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REM sleep deprivation decreases apomorphine-induced stimulation of locomotor activity but not stereotyped behavior in mice
Gen. Pharmac. Vol. 23, No. 3, pp. 337-341, 1992 Printed in Great Britain. All rights reserved
0306-3623/92 $5.00 + 0.00 Copyright © 1992 Pergamon Press Ltd
REM SLEEP DEPRIVATION DECREASES APOMORPHINE-INDUCED STIMULATION OF LOCOMOTOR ACTIVITY BUT NOT STEREOTYPED BEHAVIOR IN MICE WATARU ASAKURA, KINZO MATSUMOTO,HIROYUKI OHTA and HIROSHI WATANABE* Section of Pharmacology, Research Institute for Wakan-Yaku (Oriental Medicines), Toyama Medical and Pharmaceutical University, Toyama 930-01, Japan (Received 7 October 1991)
Abstract--1. Effects of rapid eye movement (REM) sleep deprivation on central dopaminergic system were investigated by testing the behavioral responses to apomorphine and brain dopamine metabolism in mice. 2. REM sleep deprivation for 48 hr significantly suppressed apomorphine. HC1 (3.0 and 6.0 mg/kg, i.p.)stimulated spontaneous locomotor activity without affecting the intensity of stereotyped behavior. 3. Neither the latency of nociceptive response in a hot-plate test nor the duration of pentobarbitalinduced sleep was changed by REM sleep deprivation. 4. Dopamine turnover in the striatum and the nucleus accumbens of REM sleep-deprived mice was significantly higher than that of control animals. 5. These results suggest that REM sleep deprivation may decrease the function of postsynaptic dopamine receptor in the mesolimbic but not nigrostriatal dopaminergic system.
INTRODUCTION
MATERIALS AND METHODS
Deprivation of rapid eye movement (REM) sleep causes several behavioral changes in animals and humans (Vogel, 1975). It enhances dopamine (DA) agonists-induced aggressive behavior (Ferguson and Dement, 1969; Tufik et al., 1978; Tufik, 1981; Mogilnicka, 1981; Zelger and Carlini, 1982), episodic excitation (Trotta, 1984), stereotyped behavior (Tufik et al., 1978; Troncone et al., 1988) and locomotor activity (Arriaga et al., 1988) in rats. Those R E M sleep deprivation-induced changes in the responses to D A agonists have been explained to be due to either supersensitivity of postsynaptic D A receptor (Tufik et al., 1978; Tufik, 1981) or subsensitivity of presynaptic D A receptor (Serra et al., 1981; Tufik et al., 1987) in the rat brain. On the other hand, R E M sleep deprivation has been shown to affect specifcally the function of several DAergic systems. For example, R E M sleep deprivation increases D~ receptor density in mesolimbic area but not striatum in rats (Demontis et al., 1990). However, there are few behavioral evidences that R E M sleep deprivation changes the function of mesolimbic DAergic system. To clarify whether R E M sleep deprivation differently affects the function of nigrostriatal and mesolimbic DAergic system, we investigated the effects of R E M sleep deprivation on apomorphineinduced increase in locomotor activity and stereotyped behavior in mice, and on D A metabolism in the striatum and the mesolimbic area of the mouse brain.
Animals Male ddY mice (4 weeks old) were obtained from Nippon SLC (Shizuoka, Japan) and were housed [20-30 mice per cage (35 x 30 × 16cm)] for at least a week before the experiments. Housing conditions were thermostatically maintained at 25 + I°C, with a 12 hr light/dark cycle (light on at 07:30 a.m.). Food and water were given ad libitum. R E M sleep deprivation REM sleep was deprived using small pedestal (platform) method described by Morden et al. (1967) with slight modification for mice. Briefly, the animal was individually placed in REM sleep deprivation chamber (20 × 15 × 21 cm) at the light period and housed for 48 hr with free access to food and water. The chamber was consisted of a pedestal (1.8 cm dia, 4.5 cm height) surrounded by water (3.5 cm depth). Control mice were socially isolated for 48 hr in the plexiglas cage (25 x 18 × 12cm) with wood chip. After REM sleep deprivation or isolation, each mouse was individually placed in the new plexiglas cage. Behavioral experiments Locomotor activity was measured using animal movement analyzing systems (Scanet SV-10, MATYS, Toyama, Japan). The system consisted of rectangular enclosure (40× 38cm) of which side walls (12cm height) were equipped with 144 pairs of photosensors. Each pair of photosensors was scanned every 0.1 sec to detect animal movements. Locomotor activity was calculated from the scanning data and accumulated every 5min. One hundred minutes after the end of REM sleep deprivation, each mouse was individually placed in a transparent plexiglas cage (25 x 18 × 24 cm) which was fixed at the center of the apparatus, and the locomotor activity was measured. After 80 rain habituation, apomorphine was injected (i.p.). Measurement of stereotyped behavior was carried out in a cage (24 × 12 × 15 cm) of which side walls were made of
*To whom all correspondence should be addressed.
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Fig. 1. Time-course of apomorphine-induced stimulation of locomotor activity in control and REM sleepdeprived mice. Control ((3) and REM sleep-deprived ( 0 ) mice were housed for 48 hr in a socially isolated cage and a REM sleep deprivation chamber which consists of a small pedestal surrounding water, respectively. One hundred minutes after the end of isolation or REM sleep deprivation, each mouse was individually placed in the plexiglas cage, habituated for 80 min, and given apomorphine. HCI (A, 0.75; B, 1.5; C, 3.0; D, 6.0 mg/kg, i.p.). Locomotor activity was measured every 5 min. The arrow indicates apomorphine injection. Each point represents the mean value of locomotor activity for 5 min obtained from 20 mice. wire mesh (mesh size 1 cm, wire dia 2 mm). Each mouse was individually placed in the cage 100min after the end of REM sleep deprivation, habituated for 80 min, and given apomorphine (i.p.). Rating of stereotyped behavior was
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carried out for 30 sec in a 5 min interval over a 60 min period. Stereotyped behavior was scored as described by Randall and Randall (1986): 0, no drug effect; 1, decreased locomotor activity; 2, intermittent sniffing; 3, continuous sniffing; 4, upright, intermittent sniffing; 5, upright, continuous sniffing; 6, extreme upright position, continuous oral behavior. Behavioral changes were recorded by a video camera for later analysis. The duration of pentobarbital-induced sleep and the latency of nociceptive response in a hot-plate test were measured as described by Matsumoto et al. (1991b) with minor modifications. Briefly, 60 min after the end of REM sleep deprivation, pentobarbital.Na (64mg/kg, i.p.) was administered and sleeping time was measured. In the hotplate test, 10 min after the end of REM sleep deprivation, mice were placed on the hot-plate maintained at 51-53°C. The latency of nociceptive response such as licking or flicking of hind limb or jumping was measured. Catecholamine assay
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Apomorphine HCl(mg/kg) Fig. 2. Effect of REM sleep deprivation on locomotor activity stimulated by apomorphine in mice. Open and solid circles represent the data obtained from control and REM sleep-deprived mice, respectively. Each point represents the mean value of locomotor activity for 60 min after apomorphine administration obtained from 20-30 mice. *P < 0.05, **P < 0.01, compared with control mice (Mann-Whitney U-test).
Mice were decapitated 180min after the end of REM sleep deprivation. The brains were rapidly removed and washed in ice-cold saline. The striatum and the nucleus accumbens were dissected on an ice-cold glass plate and frozen in liquid nitrogen. After weighing, each tissue was homogenized in 1 ml ice-cold perchloric acid solution (0.25 M) containing 0.3 mg cysteine and 40 ng 3,4-dihydroxybenzylamine as an internal standard. After centrifugation (10,000g, 4°C for 10min), the supernatant and 30mg acid-washed alumina were added to 1 ml Tris-HC1 buffer (1.5 M, pH 8.6) and shaken (250 rpm) at 4°C for l0 min. The
339
REM deprivation and DAergic system
Table 1. Effect of REM sleep deprivation on the duration of pentobarbital-induced sleep and the latency of nociceptive response in the hot-plate test in mice
30-
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3.0
6.0
Apomorphlne. HCI (rng/kg)
Fig. 3. Effect of REM sleep deprivation on apomorphine-induced stereotyped behavior in mice. Open and solid circles represent the data obtained from control and REM sleepdeprived mice, respectively. Each point represents the mean value of total score of stereotyped behavior for 60 min after apomorphine administration obtained from 15 mice. alumina was washed 3 times with distilled water. Catecholamines adsorbed to the alumina were eluated with 0.3 ml perchloric acid solution (0.25M) containing cysteine (0. l mg/ml) and determined with a high performance liquid chromatography with electrochemical detector (HPLCECD).
Drugs Pentobarbital. Na (Toyko Kasei) and apomorphine-HC1 (Sigma) were dissolved in saline and that containing 0.03% ascorbic acid, respectively, just before the experiments. Test drugs were injected i.p. at a volume of 10 ml/kg.
Statistics The significant differences ( P <0.05) in locomotor activity and stereotyped behavior were evaluated with non-parametric two-tailed Mann-Whitney U-test. The significant differences ( P < 0.05) in the duration of pentobarbital-induced sleep, the latency of nociceptive response and brain catecholamine levels were calculated by parametric two-tailed Student's t-test following one-way analysis of variance (ANOVA).
(A) (B) Duration of sleep Latency of nociceptive Treatment (min) response (see) Control 67 + 5.8 14.9 ± 2.6 REMSD 54 ± 5.2 11.6 ± 1.7 Control and REM sleep-deprived (REMSD) mice were housed for 48 hr in a socially isolated cage and a REM sleep deprivation chamber, respectively. (A) 60 min after the end of isolation or REM sleep deprivation, pentobarbital.Na (64mg/kg, i.p.) was administered and the duration of sleep was measured. (B) 10 min after the end of isolation or REM sleep deprivation, a mouse was put on the hot-plate maintained at 51 53'C. The latency of nociceptive response was measured. Each data represents the mean value obtained from 10 mice, with the SEM indicated.
When locomotor activity was accumulated for 60 min after apomorphine administration, the d o s e - r e s p o n s e r e l a t i o n s h i p was shifted d o w n w a r d by R E M sleep d e p r i v a t i o n (Fig. 2). A p o m o r p h i n e (3 a n d 6 m g / k g ) - s t i m u l a t e d l o c o m o t o r activities in R E M sleep-deprived mice were significantly lower t h a n t h o s e in c o n t r o l animals, while the basal l o c o m o t o r activity in the R E M sleep-deprived mice was slightly b u t n o t significantly higher t h a n that in the c o n t r o l animals. A p o m o r p h i n e (0.75-6.0 m g / k g ) p r o d u c e d stereotyped b e h a v i o r d o s e - d e p e n d e n t l y , w h e r e a s the intensity o f the b e h a v i o r in R E M sleep-deprived mice did n o t differ f r o m that in the c o n t r o l a n i m a l s (Fig. 3). N e i t h e r the latency o f nociceptive r e s p o n s e in the h o t - p l a t e test n o r the d u r a t i o n o f p e n t o b a r b i t a l i n d u c e d sleep in R E M sleep-deprived mice significantly differed f r o m t h o s e in the c o n t r o l a n i m a l s (Table |). D A levels in the s t r i a t u m a n d the nucleus a c c u m bens o f R E M sleep-deprived mice did n o t significantly differ f r o m t h o s e o f the c o n t r o l animals, w h e r e a s 3 , 4 - d i h y d r o x y p h e n y l a c e t i c acid ( D O P A C ) levels in t h o s e tissues o f R E M sleep-deprived mice were significantly higher t h a n t h o s e o f c o n t r o l a n i m a l s (Table 2).
RESULTS A p o m o r p h i n e ( 0 . 7 5 - 6 . 0 m g / k g ) s t i m u l a t e d the s p o n t a n e o u s l o c o m o t o r activity in c o n t r o l a n d R E M s l e e p - d e p r i v e d mice (Fig. 1). T h e d u r a t i o n o f apomorphine-induced stimulation of spontaneous l o c o m o t o r activity d o s e - d e p e n d e n t l y b e c a m e long, w h e r e a s the p e a k values in the c o n t r o l a n d R E M s l e e p - d e p r i v e d mice t e n d e d to b e c o m e lower as the d o s e s o f a p o m o r p h i n e increased.
DISCUSSION
The present results demonstrate that REM sleep deprivation decreases locomotor responses to high doses of apomorphine in mice. These findings are in contrast to the data reported by other group that d-amphetamine-induced increase in locomotor activity is higher in REM sleep-deprived rats than in
Table 2. Effect of REM sleep deprivation on DA and DOPAC levels in the mouse brain DA (,ug/g tissue) DOPAC (,ug/g tissue) Treatment Striatum Accumbens Striatum Accumbens Control REMSD
12.1 + 0.47 12.2 _+0.54
10.7 + 0.64 10.0 ± 0.32
0.92 + 0.06 1.26 _+.0.09*
1.05 + 0.09 1.36 + 0.06*
Control and REM sleep-deprived (REMSD) mice were housed for 48 hr in a socially isolated cage and a REM sleep deprivation chamber, respectively. Each mouse was decapitated 180 min after the end of isolation or REM sleep deprivation. DA and DOPAC in the striatum and the nucleus accumbens were assayed using HPLC-ECD. Each data represents the mean value of 9 10 mice, with the SEM indicated. *P < 0.01 compared with control mice (Student's t-test).
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control animals (Arriaga et al., 1988). The reasons for this discrepancy remain unclear but it may be due to species difference of animals used and/or difference in experimental procedures. Various stress manipulations have been shown to affect not only the behavioral responses to DA agonists (Cabib et al., 1984, 1988; Gleiter and Nutt, 1989) but also the latency of nociceptive response in the hot-plate test and/or the duration of barbiturateinduced sleep (Willow et al., 1980; Carmody, 1983). Involvement of stressful factors in the present results cannot be excluded, since the small pedestal method used in this study limits animal movements within the pedestal area and causes mice to soak their tails in water. However, neither the duration of pentobarbital-induced sleep nor the latency of nociceptive response in the hot-plate test significantly changed in REM sleep-deprived mice. Therefore, the involvement of stress factors in REM sleep deprivationinduced changes of locomotor responses to apomorphine may be slight, if any. The dose-response curve of apomorphine-induced increase in spontaneous locomotor activity shifted toward the downward in REM sleep-deprived mice. The results suggest the possibility that the decreases of apomorphine-stimulated locomotor activity in REM sleep-deprived mice may be due to the behavioral switching by higher doses of DA agonist from hyperactivity to potentiated stereotyped behavior such as biting, licking and/or sniffing (Kelly, 1977; Hirabayashi et al., 1979). However, this does not seem to be the case, because there were no significant differences in apomorphine (3.0 and 6.0 mg/kg)-induced stereotyped behavior between the control and REM sleep deprived animals. On the other hand, apomorphine-induced grooming does not seem to affect the apomorphine-stimulated locomotor activity, since apomorphine-induced grooming behavior appeared in parallel with the termination of locomotor activity induced by apomorphine rather than with its appearance (data not shown) in consistent with our previous observation (Matsumoto et al., 1991a). Therefore, the decrease in locomotor response to apomorphine in REM sleep-deprived mice may be due to the decrease in DA receptor function. Apomorphine-induced hyperactivity and stereotyped behavior have been shown to be predominantly mediated by stimulation of postsynaptic DA receptors (Iversen, 1977) in mesolimbic and nigrostriatal DAergic systems, respectively (Kelly, 1977; Van Ree et al., 1989). Therefore, the facts that REM sleep deprivation decreases apomorphine-induced increase of locomotor activity but not stereotyped behavior suggest that REM sleep deprivation decreases the postsynaptic DA receptor function in mesolimbic but not nigrostriatal DAergic system in the mouse brain. When examined 180 rain after the end of REM sleep deprivation, the present neurochemical analysis indicates that DAergic neuronal activities in the nucleus accumbens and the striatum of REM sleep-deprived mice are higher than those of the control animals. However, the changes in behavioral responses to apomorphine in REM sleep-deprived mice do not reflect the presynaptic effects of REM sleep deprivation, since the doses of apomorphine tested here
are considered to be enough to stimulate postsynaptic DA receptor predominantly. In conclusion, the results that REM sleep deprivation decreases the locomotor response to apomorphine may be derived from the functional change in postsynaptic DA receptor in mesolimbic but not in nigrostriatal DAergic system of the mouse brain. REFERENCES
Arriaga F., Dugovic C. and Wauquier A. (1988) Effects of lithium on dopamine behavioural supersensitivityinduced by rapid eye movement sleep deprivation. Neuropsychobiology 20, 23 27. Cabib S., Puglisi-AllegraS. and Oliverio A. (1984) Chronic stress enhances apomorphine-induced stereotyped behavior in mice: involvement of endogenous opioids. Brain Res. 298, 138-140. Cabib S, Kempf E., SchleefC., Mele A. and Puglisi-Allegra S. (1988) Different effects of acute and chronic stress on two dopamine-mediated behaviors in the mouse. Physiol. Behav. 43, 223-227. Carmody J. (1983) Effects of electric footshock on barbiturate sensitivity, nociception and body temperature in mice. Eur. J. Pharmac. 89, 119-123. Demontis M. G., Fadda P., Devoto P., Martellotta M. C. and Fratta W. (1990) Sleep deprivation increases dopamine D t receptor agonist [3H]SCH 23390 binding and dopamine-stimulated adenylate cyclase in the rat limbic system. Neurosci. Lett. 117, 224 227. Ferguson J. and Dement W. (1969) The behavioral effects of amphetamine on REM deprived rats. J. Psychiat. Res. 7, 111--118. Gleiter C. H. and Nutt D. J. (1989) Chronic electroconvulsive shock and neurotransmitter receptors--an update. Life Sci. 44, 985 1006. Hirabayashi M., Iwai F., Iizuka M., Mesaki T., Alam M. R. and Tadokoro S. (1979) Individual differences in the accelerating effect of methamphetamine, d-amphetamine and morphine on ambulatory activity in mice. (Abstract in English) Folia pharmac, jap. 75, 6834593. Iversen S. D. (1977) Brain dopamine systems and behavior. In Handbook of Psychopharmacology (Edited by Iversen L. L., Iversen S. D. and Snyder S. H.), Vol. 8, pp. 333-384. Plenum Press, New York. Kelly P. H. (1977) Drug-induce motor behavior. In Handbook o f Psychopharmacology (Edited by Iversen L. L., Iversen S. D. and Snyder S. H.), Vol. 8, pp. 295-331. Plenum Press, New York. Matsumoto K., Cai B., Ohta H., lmamura L. and Watanabe H. (1991a) Apparent enhancement by SCH 23390 of apomorphine-induced locomotor activity in mice. Pharmac. Biochem. Behav. 39, 699 703. Matsumoto K., Satoh T., Li H. B., Ohta H. and Watanabe H. (1991b) Effects of forced shaking stress at low temperature on pentobarbital-induced sleeping in mice. Gen. Pharmac. 22, 729-733. Mogilnicka E. (1981) REM sleep deprivation changes behavioral response to catecholaminergic and serotonergic receptor activation in rats. Pharmac. Biochem. Behav. 15, 149 151. Morden B., Mitchell G. and Dement W. (1967) Selective REM sleep deprivation and compensation phenomena in the rat. Brain Res. 5, 339-349. Randall P. K. and Randall J. S. (1986) Mouse strain differences in apomorphine-induced behavior: an empirical and methodological study. Behav. Neurosci. I00, 85-92. Serra G., Melis M. R., Argiolas A., Fadda F. and Gessa G. L. (1981) REM sleep deprivation induces subsensitivity of dopamine receptors mediating sedation in rats. Eur. J. Pharmac. 72, 131-135.
REM deprivation and DAergic system Troncone L. R. P., Ferreira T. M. S., Braz S., Silveira Filho N. G. and Tufik S. (1988) Reversal of the increase in apomorphine-induced stereotypy and aggression in REM sleep deprived rats by dopamine agonist pretreatments. Psychopharmacology 94, 79-83. Trotta E. E. (1984) Episodic excitation and changes in aggressive behavior induced by apomorphine in rats subjected to REM sleep deprivation. Neuropharmacology 23, 1053-1057. Tufik S. (1981) Changes of response to dopaminergic drugs in rats submitted to REM-sleep deprivation. Psychopharmacology 72, 257 260. Tufik S., Lindsey C. J. and Carlini E. A. (1978) Does REM sleep deprivation induce a supersensitivity of dopaminergic receptors in the rat brain? Pharmacology 16, 98-105. Tufik S., Troncone L. R. P., Braz S., Silva-Filho A. R. and Neumann B. G. (1987) Does REM sleep deprivation
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induce subsensitivity of presynaptic dopamine or postsynaptic acetylcholine receptors in the rat brain? Eur. J. Pharmac. 140, 215-219. Van Ree J. M., Elands J., Kiraly I. and Wolterink G. (1989) Antipsychotie substances and dopamine in the rat brain; behavioral studies reveal distinct dopamine receptor systems. Eur. J. Pharmac. 166, 441-452. Vogel G. W. (1975) A review of REM sleep deprivation. Archs Gen. Psychiat. 32, 749-761. Willow M., Carmody J. and Carroll P. (1980) The effects of swimming in mice on pain perception and sleeping time in response to hypnotic drugs. Life Sci. 26, 219~24. Zelger K. D. and Carlini E. A. (1982) The persistence of hyperresponsiveness to apomorphine in rats following REM sleep deprivation and the influence of housing conditions. Eur. J. Pharmac. 80, 99 104.
0306-3623/92 $5.00 + 0.00 Copyright © 1992 Pergamon Press Ltd
REM SLEEP DEPRIVATION DECREASES APOMORPHINE-INDUCED STIMULATION OF LOCOMOTOR ACTIVITY BUT NOT STEREOTYPED BEHAVIOR IN MICE WATARU ASAKURA, KINZO MATSUMOTO,HIROYUKI OHTA and HIROSHI WATANABE* Section of Pharmacology, Research Institute for Wakan-Yaku (Oriental Medicines), Toyama Medical and Pharmaceutical University, Toyama 930-01, Japan (Received 7 October 1991)
Abstract--1. Effects of rapid eye movement (REM) sleep deprivation on central dopaminergic system were investigated by testing the behavioral responses to apomorphine and brain dopamine metabolism in mice. 2. REM sleep deprivation for 48 hr significantly suppressed apomorphine. HC1 (3.0 and 6.0 mg/kg, i.p.)stimulated spontaneous locomotor activity without affecting the intensity of stereotyped behavior. 3. Neither the latency of nociceptive response in a hot-plate test nor the duration of pentobarbitalinduced sleep was changed by REM sleep deprivation. 4. Dopamine turnover in the striatum and the nucleus accumbens of REM sleep-deprived mice was significantly higher than that of control animals. 5. These results suggest that REM sleep deprivation may decrease the function of postsynaptic dopamine receptor in the mesolimbic but not nigrostriatal dopaminergic system.
INTRODUCTION
MATERIALS AND METHODS
Deprivation of rapid eye movement (REM) sleep causes several behavioral changes in animals and humans (Vogel, 1975). It enhances dopamine (DA) agonists-induced aggressive behavior (Ferguson and Dement, 1969; Tufik et al., 1978; Tufik, 1981; Mogilnicka, 1981; Zelger and Carlini, 1982), episodic excitation (Trotta, 1984), stereotyped behavior (Tufik et al., 1978; Troncone et al., 1988) and locomotor activity (Arriaga et al., 1988) in rats. Those R E M sleep deprivation-induced changes in the responses to D A agonists have been explained to be due to either supersensitivity of postsynaptic D A receptor (Tufik et al., 1978; Tufik, 1981) or subsensitivity of presynaptic D A receptor (Serra et al., 1981; Tufik et al., 1987) in the rat brain. On the other hand, R E M sleep deprivation has been shown to affect specifcally the function of several DAergic systems. For example, R E M sleep deprivation increases D~ receptor density in mesolimbic area but not striatum in rats (Demontis et al., 1990). However, there are few behavioral evidences that R E M sleep deprivation changes the function of mesolimbic DAergic system. To clarify whether R E M sleep deprivation differently affects the function of nigrostriatal and mesolimbic DAergic system, we investigated the effects of R E M sleep deprivation on apomorphineinduced increase in locomotor activity and stereotyped behavior in mice, and on D A metabolism in the striatum and the mesolimbic area of the mouse brain.
Animals Male ddY mice (4 weeks old) were obtained from Nippon SLC (Shizuoka, Japan) and were housed [20-30 mice per cage (35 x 30 × 16cm)] for at least a week before the experiments. Housing conditions were thermostatically maintained at 25 + I°C, with a 12 hr light/dark cycle (light on at 07:30 a.m.). Food and water were given ad libitum. R E M sleep deprivation REM sleep was deprived using small pedestal (platform) method described by Morden et al. (1967) with slight modification for mice. Briefly, the animal was individually placed in REM sleep deprivation chamber (20 × 15 × 21 cm) at the light period and housed for 48 hr with free access to food and water. The chamber was consisted of a pedestal (1.8 cm dia, 4.5 cm height) surrounded by water (3.5 cm depth). Control mice were socially isolated for 48 hr in the plexiglas cage (25 x 18 × 12cm) with wood chip. After REM sleep deprivation or isolation, each mouse was individually placed in the new plexiglas cage. Behavioral experiments Locomotor activity was measured using animal movement analyzing systems (Scanet SV-10, MATYS, Toyama, Japan). The system consisted of rectangular enclosure (40× 38cm) of which side walls (12cm height) were equipped with 144 pairs of photosensors. Each pair of photosensors was scanned every 0.1 sec to detect animal movements. Locomotor activity was calculated from the scanning data and accumulated every 5min. One hundred minutes after the end of REM sleep deprivation, each mouse was individually placed in a transparent plexiglas cage (25 x 18 × 24 cm) which was fixed at the center of the apparatus, and the locomotor activity was measured. After 80 rain habituation, apomorphine was injected (i.p.). Measurement of stereotyped behavior was carried out in a cage (24 × 12 × 15 cm) of which side walls were made of
*To whom all correspondence should be addressed.
337
338
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ASAKURA
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Fig. 1. Time-course of apomorphine-induced stimulation of locomotor activity in control and REM sleepdeprived mice. Control ((3) and REM sleep-deprived ( 0 ) mice were housed for 48 hr in a socially isolated cage and a REM sleep deprivation chamber which consists of a small pedestal surrounding water, respectively. One hundred minutes after the end of isolation or REM sleep deprivation, each mouse was individually placed in the plexiglas cage, habituated for 80 min, and given apomorphine. HCI (A, 0.75; B, 1.5; C, 3.0; D, 6.0 mg/kg, i.p.). Locomotor activity was measured every 5 min. The arrow indicates apomorphine injection. Each point represents the mean value of locomotor activity for 5 min obtained from 20 mice. wire mesh (mesh size 1 cm, wire dia 2 mm). Each mouse was individually placed in the cage 100min after the end of REM sleep deprivation, habituated for 80 min, and given apomorphine (i.p.). Rating of stereotyped behavior was
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carried out for 30 sec in a 5 min interval over a 60 min period. Stereotyped behavior was scored as described by Randall and Randall (1986): 0, no drug effect; 1, decreased locomotor activity; 2, intermittent sniffing; 3, continuous sniffing; 4, upright, intermittent sniffing; 5, upright, continuous sniffing; 6, extreme upright position, continuous oral behavior. Behavioral changes were recorded by a video camera for later analysis. The duration of pentobarbital-induced sleep and the latency of nociceptive response in a hot-plate test were measured as described by Matsumoto et al. (1991b) with minor modifications. Briefly, 60 min after the end of REM sleep deprivation, pentobarbital.Na (64mg/kg, i.p.) was administered and sleeping time was measured. In the hotplate test, 10 min after the end of REM sleep deprivation, mice were placed on the hot-plate maintained at 51-53°C. The latency of nociceptive response such as licking or flicking of hind limb or jumping was measured. Catecholamine assay
3J0
610
Apomorphine HCl(mg/kg) Fig. 2. Effect of REM sleep deprivation on locomotor activity stimulated by apomorphine in mice. Open and solid circles represent the data obtained from control and REM sleep-deprived mice, respectively. Each point represents the mean value of locomotor activity for 60 min after apomorphine administration obtained from 20-30 mice. *P < 0.05, **P < 0.01, compared with control mice (Mann-Whitney U-test).
Mice were decapitated 180min after the end of REM sleep deprivation. The brains were rapidly removed and washed in ice-cold saline. The striatum and the nucleus accumbens were dissected on an ice-cold glass plate and frozen in liquid nitrogen. After weighing, each tissue was homogenized in 1 ml ice-cold perchloric acid solution (0.25 M) containing 0.3 mg cysteine and 40 ng 3,4-dihydroxybenzylamine as an internal standard. After centrifugation (10,000g, 4°C for 10min), the supernatant and 30mg acid-washed alumina were added to 1 ml Tris-HC1 buffer (1.5 M, pH 8.6) and shaken (250 rpm) at 4°C for l0 min. The
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Table 1. Effect of REM sleep deprivation on the duration of pentobarbital-induced sleep and the latency of nociceptive response in the hot-plate test in mice
30-
O o)
20
o 10
8 O3 I
.75
I
f
I
1.5
3.0
6.0
Apomorphlne. HCI (rng/kg)
Fig. 3. Effect of REM sleep deprivation on apomorphine-induced stereotyped behavior in mice. Open and solid circles represent the data obtained from control and REM sleepdeprived mice, respectively. Each point represents the mean value of total score of stereotyped behavior for 60 min after apomorphine administration obtained from 15 mice. alumina was washed 3 times with distilled water. Catecholamines adsorbed to the alumina were eluated with 0.3 ml perchloric acid solution (0.25M) containing cysteine (0. l mg/ml) and determined with a high performance liquid chromatography with electrochemical detector (HPLCECD).
Drugs Pentobarbital. Na (Toyko Kasei) and apomorphine-HC1 (Sigma) were dissolved in saline and that containing 0.03% ascorbic acid, respectively, just before the experiments. Test drugs were injected i.p. at a volume of 10 ml/kg.
Statistics The significant differences ( P <0.05) in locomotor activity and stereotyped behavior were evaluated with non-parametric two-tailed Mann-Whitney U-test. The significant differences ( P < 0.05) in the duration of pentobarbital-induced sleep, the latency of nociceptive response and brain catecholamine levels were calculated by parametric two-tailed Student's t-test following one-way analysis of variance (ANOVA).
(A) (B) Duration of sleep Latency of nociceptive Treatment (min) response (see) Control 67 + 5.8 14.9 ± 2.6 REMSD 54 ± 5.2 11.6 ± 1.7 Control and REM sleep-deprived (REMSD) mice were housed for 48 hr in a socially isolated cage and a REM sleep deprivation chamber, respectively. (A) 60 min after the end of isolation or REM sleep deprivation, pentobarbital.Na (64mg/kg, i.p.) was administered and the duration of sleep was measured. (B) 10 min after the end of isolation or REM sleep deprivation, a mouse was put on the hot-plate maintained at 51 53'C. The latency of nociceptive response was measured. Each data represents the mean value obtained from 10 mice, with the SEM indicated.
When locomotor activity was accumulated for 60 min after apomorphine administration, the d o s e - r e s p o n s e r e l a t i o n s h i p was shifted d o w n w a r d by R E M sleep d e p r i v a t i o n (Fig. 2). A p o m o r p h i n e (3 a n d 6 m g / k g ) - s t i m u l a t e d l o c o m o t o r activities in R E M sleep-deprived mice were significantly lower t h a n t h o s e in c o n t r o l animals, while the basal l o c o m o t o r activity in the R E M sleep-deprived mice was slightly b u t n o t significantly higher t h a n that in the c o n t r o l animals. A p o m o r p h i n e (0.75-6.0 m g / k g ) p r o d u c e d stereotyped b e h a v i o r d o s e - d e p e n d e n t l y , w h e r e a s the intensity o f the b e h a v i o r in R E M sleep-deprived mice did n o t differ f r o m that in the c o n t r o l a n i m a l s (Fig. 3). N e i t h e r the latency o f nociceptive r e s p o n s e in the h o t - p l a t e test n o r the d u r a t i o n o f p e n t o b a r b i t a l i n d u c e d sleep in R E M sleep-deprived mice significantly differed f r o m t h o s e in the c o n t r o l a n i m a l s (Table |). D A levels in the s t r i a t u m a n d the nucleus a c c u m bens o f R E M sleep-deprived mice did n o t significantly differ f r o m t h o s e o f the c o n t r o l animals, w h e r e a s 3 , 4 - d i h y d r o x y p h e n y l a c e t i c acid ( D O P A C ) levels in t h o s e tissues o f R E M sleep-deprived mice were significantly higher t h a n t h o s e o f c o n t r o l a n i m a l s (Table 2).
RESULTS A p o m o r p h i n e ( 0 . 7 5 - 6 . 0 m g / k g ) s t i m u l a t e d the s p o n t a n e o u s l o c o m o t o r activity in c o n t r o l a n d R E M s l e e p - d e p r i v e d mice (Fig. 1). T h e d u r a t i o n o f apomorphine-induced stimulation of spontaneous l o c o m o t o r activity d o s e - d e p e n d e n t l y b e c a m e long, w h e r e a s the p e a k values in the c o n t r o l a n d R E M s l e e p - d e p r i v e d mice t e n d e d to b e c o m e lower as the d o s e s o f a p o m o r p h i n e increased.
DISCUSSION
The present results demonstrate that REM sleep deprivation decreases locomotor responses to high doses of apomorphine in mice. These findings are in contrast to the data reported by other group that d-amphetamine-induced increase in locomotor activity is higher in REM sleep-deprived rats than in
Table 2. Effect of REM sleep deprivation on DA and DOPAC levels in the mouse brain DA (,ug/g tissue) DOPAC (,ug/g tissue) Treatment Striatum Accumbens Striatum Accumbens Control REMSD
12.1 + 0.47 12.2 _+0.54
10.7 + 0.64 10.0 ± 0.32
0.92 + 0.06 1.26 _+.0.09*
1.05 + 0.09 1.36 + 0.06*
Control and REM sleep-deprived (REMSD) mice were housed for 48 hr in a socially isolated cage and a REM sleep deprivation chamber, respectively. Each mouse was decapitated 180 min after the end of isolation or REM sleep deprivation. DA and DOPAC in the striatum and the nucleus accumbens were assayed using HPLC-ECD. Each data represents the mean value of 9 10 mice, with the SEM indicated. *P < 0.01 compared with control mice (Student's t-test).
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control animals (Arriaga et al., 1988). The reasons for this discrepancy remain unclear but it may be due to species difference of animals used and/or difference in experimental procedures. Various stress manipulations have been shown to affect not only the behavioral responses to DA agonists (Cabib et al., 1984, 1988; Gleiter and Nutt, 1989) but also the latency of nociceptive response in the hot-plate test and/or the duration of barbiturateinduced sleep (Willow et al., 1980; Carmody, 1983). Involvement of stressful factors in the present results cannot be excluded, since the small pedestal method used in this study limits animal movements within the pedestal area and causes mice to soak their tails in water. However, neither the duration of pentobarbital-induced sleep nor the latency of nociceptive response in the hot-plate test significantly changed in REM sleep-deprived mice. Therefore, the involvement of stress factors in REM sleep deprivationinduced changes of locomotor responses to apomorphine may be slight, if any. The dose-response curve of apomorphine-induced increase in spontaneous locomotor activity shifted toward the downward in REM sleep-deprived mice. The results suggest the possibility that the decreases of apomorphine-stimulated locomotor activity in REM sleep-deprived mice may be due to the behavioral switching by higher doses of DA agonist from hyperactivity to potentiated stereotyped behavior such as biting, licking and/or sniffing (Kelly, 1977; Hirabayashi et al., 1979). However, this does not seem to be the case, because there were no significant differences in apomorphine (3.0 and 6.0 mg/kg)-induced stereotyped behavior between the control and REM sleep deprived animals. On the other hand, apomorphine-induced grooming does not seem to affect the apomorphine-stimulated locomotor activity, since apomorphine-induced grooming behavior appeared in parallel with the termination of locomotor activity induced by apomorphine rather than with its appearance (data not shown) in consistent with our previous observation (Matsumoto et al., 1991a). Therefore, the decrease in locomotor response to apomorphine in REM sleep-deprived mice may be due to the decrease in DA receptor function. Apomorphine-induced hyperactivity and stereotyped behavior have been shown to be predominantly mediated by stimulation of postsynaptic DA receptors (Iversen, 1977) in mesolimbic and nigrostriatal DAergic systems, respectively (Kelly, 1977; Van Ree et al., 1989). Therefore, the facts that REM sleep deprivation decreases apomorphine-induced increase of locomotor activity but not stereotyped behavior suggest that REM sleep deprivation decreases the postsynaptic DA receptor function in mesolimbic but not nigrostriatal DAergic system in the mouse brain. When examined 180 rain after the end of REM sleep deprivation, the present neurochemical analysis indicates that DAergic neuronal activities in the nucleus accumbens and the striatum of REM sleep-deprived mice are higher than those of the control animals. However, the changes in behavioral responses to apomorphine in REM sleep-deprived mice do not reflect the presynaptic effects of REM sleep deprivation, since the doses of apomorphine tested here
are considered to be enough to stimulate postsynaptic DA receptor predominantly. In conclusion, the results that REM sleep deprivation decreases the locomotor response to apomorphine may be derived from the functional change in postsynaptic DA receptor in mesolimbic but not in nigrostriatal DAergic system of the mouse brain. REFERENCES
Arriaga F., Dugovic C. and Wauquier A. (1988) Effects of lithium on dopamine behavioural supersensitivityinduced by rapid eye movement sleep deprivation. Neuropsychobiology 20, 23 27. Cabib S., Puglisi-AllegraS. and Oliverio A. (1984) Chronic stress enhances apomorphine-induced stereotyped behavior in mice: involvement of endogenous opioids. Brain Res. 298, 138-140. Cabib S, Kempf E., SchleefC., Mele A. and Puglisi-Allegra S. (1988) Different effects of acute and chronic stress on two dopamine-mediated behaviors in the mouse. Physiol. Behav. 43, 223-227. Carmody J. (1983) Effects of electric footshock on barbiturate sensitivity, nociception and body temperature in mice. Eur. J. Pharmac. 89, 119-123. Demontis M. G., Fadda P., Devoto P., Martellotta M. C. and Fratta W. (1990) Sleep deprivation increases dopamine D t receptor agonist [3H]SCH 23390 binding and dopamine-stimulated adenylate cyclase in the rat limbic system. Neurosci. Lett. 117, 224 227. Ferguson J. and Dement W. (1969) The behavioral effects of amphetamine on REM deprived rats. J. Psychiat. Res. 7, 111--118. Gleiter C. H. and Nutt D. J. (1989) Chronic electroconvulsive shock and neurotransmitter receptors--an update. Life Sci. 44, 985 1006. Hirabayashi M., Iwai F., Iizuka M., Mesaki T., Alam M. R. and Tadokoro S. (1979) Individual differences in the accelerating effect of methamphetamine, d-amphetamine and morphine on ambulatory activity in mice. (Abstract in English) Folia pharmac, jap. 75, 6834593. Iversen S. D. (1977) Brain dopamine systems and behavior. In Handbook of Psychopharmacology (Edited by Iversen L. L., Iversen S. D. and Snyder S. H.), Vol. 8, pp. 333-384. Plenum Press, New York. Kelly P. H. (1977) Drug-induce motor behavior. In Handbook o f Psychopharmacology (Edited by Iversen L. L., Iversen S. D. and Snyder S. H.), Vol. 8, pp. 295-331. Plenum Press, New York. Matsumoto K., Cai B., Ohta H., lmamura L. and Watanabe H. (1991a) Apparent enhancement by SCH 23390 of apomorphine-induced locomotor activity in mice. Pharmac. Biochem. Behav. 39, 699 703. Matsumoto K., Satoh T., Li H. B., Ohta H. and Watanabe H. (1991b) Effects of forced shaking stress at low temperature on pentobarbital-induced sleeping in mice. Gen. Pharmac. 22, 729-733. Mogilnicka E. (1981) REM sleep deprivation changes behavioral response to catecholaminergic and serotonergic receptor activation in rats. Pharmac. Biochem. Behav. 15, 149 151. Morden B., Mitchell G. and Dement W. (1967) Selective REM sleep deprivation and compensation phenomena in the rat. Brain Res. 5, 339-349. Randall P. K. and Randall J. S. (1986) Mouse strain differences in apomorphine-induced behavior: an empirical and methodological study. Behav. Neurosci. I00, 85-92. Serra G., Melis M. R., Argiolas A., Fadda F. and Gessa G. L. (1981) REM sleep deprivation induces subsensitivity of dopamine receptors mediating sedation in rats. Eur. J. Pharmac. 72, 131-135.
REM deprivation and DAergic system Troncone L. R. P., Ferreira T. M. S., Braz S., Silveira Filho N. G. and Tufik S. (1988) Reversal of the increase in apomorphine-induced stereotypy and aggression in REM sleep deprived rats by dopamine agonist pretreatments. Psychopharmacology 94, 79-83. Trotta E. E. (1984) Episodic excitation and changes in aggressive behavior induced by apomorphine in rats subjected to REM sleep deprivation. Neuropharmacology 23, 1053-1057. Tufik S. (1981) Changes of response to dopaminergic drugs in rats submitted to REM-sleep deprivation. Psychopharmacology 72, 257 260. Tufik S., Lindsey C. J. and Carlini E. A. (1978) Does REM sleep deprivation induce a supersensitivity of dopaminergic receptors in the rat brain? Pharmacology 16, 98-105. Tufik S., Troncone L. R. P., Braz S., Silva-Filho A. R. and Neumann B. G. (1987) Does REM sleep deprivation
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induce subsensitivity of presynaptic dopamine or postsynaptic acetylcholine receptors in the rat brain? Eur. J. Pharmac. 140, 215-219. Van Ree J. M., Elands J., Kiraly I. and Wolterink G. (1989) Antipsychotie substances and dopamine in the rat brain; behavioral studies reveal distinct dopamine receptor systems. Eur. J. Pharmac. 166, 441-452. Vogel G. W. (1975) A review of REM sleep deprivation. Archs Gen. Psychiat. 32, 749-761. Willow M., Carmody J. and Carroll P. (1980) The effects of swimming in mice on pain perception and sleeping time in response to hypnotic drugs. Life Sci. 26, 219~24. Zelger K. D. and Carlini E. A. (1982) The persistence of hyperresponsiveness to apomorphine in rats following REM sleep deprivation and the influence of housing conditions. Eur. J. Pharmac. 80, 99 104.