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P294 The effect of antigenic stimulation on content of norepinephrine in the stomach of rats
Poster Session: Basic Neurophysiology
338
only, 2 - running followed by clonic, and 3 - running, clonic and tonic convulsions. Controls had no convulsions. In metaphit-treated (10 mg/kg, i.p.) group the incidence and seizure severity of convulsive responses raised progressively, reaching peak 8-10 h after metaphit administration (10/12 and 2.25 :tz 0.32) and then gradually declined until 30 h postinjection, when no animal responded. Metaphit + APH group: eight hours after metaphit (10 mg/kg, i.p.) administration, when incidence and seizure severity grade reached their maximum, only rats who had convulsions were injected with APH i.c.v. The doses of APH were: 0.01 (n = 5), 0.02 (n = 5) and 0.05 (n = 5)/zmol, all in 5/xl of saline. The dose of 0.01/zmol inhibited seizures in 4 of 5 rats, and in one rat attenuated severity grade (from 2 to 1). The dose of 0.02 #mol blocked seizures in all animals (515) one hour, while the dose of 0.05/zmol completely inhibited seizures (5/5) for 4 hours.
EFFECT OF LC STIMULATION ON RSA PHASE SHIFT OSCILLATIONS BETWEEN LEFT AND RIGHT HIPPOCAMPUS IN RAT
A. Kalauzi i, M. Culic 2, B. Jankovic I, j. Saponjic 2, S. Popovic 2, M. Jankovic 2. t Center for Multidisciplinat 3, studies, Belgrade,
Yugoslavia: 2 Institute for Biological Research, Belgrade, Yugoslavia As reported earlier, rhythmic slow activity (RSA) in rat recorded from left and right hippocampus show very low frequency (< 0.5 Hz) phase shift oscillations. The aim of this study was to test the effect of locus coeruleus (LC) stimulation on these oscillations. The adult Wistar rats were implanted with bipolar stainless steel electrodes for chronic recording of RSA in dorsal hippocampi at stereotaxic coordinates: P: 2.8; L/R: 1.5; H: -2.9, and for electric stimulation of left LC: P: 9.8; L: 1.2; H: -6.5. Signals were treated as amplitude modulated theta carrier frequency oscillations. Carrier frequency phase shifts (CFPS) were calculated from theta band Fourier components. CFPS time dependence was obtained using 16 sec moving window through epochs of 64 seconds. CFPS oscillations before and immediately after short lasting LC stimulation were compared both in time and frequency domain. In most cases the stimulation of LC resulted in reduction of amplitudes of CFPS oscillations.
BACLOFEN DECREASES RECURRENT INHIBITION AND INCREASES THE THETA RHYTHM IN FREELY BEHAVING RATS
A.J.R. Leal, E. Moller, W.J. Wadman. HEM, Lisboa, Portugal; UvA,
Amsterdam, The Netherlands GABA-B receptors have been demonstrated to modulate synaptic transmission and the filtering properties in the hippocampus, and suggested to play an important role in its information processing role. In order to study the effects of GABA-B receptor stimulation in the CA 1 area of the hippocampus in vivo, Baclofen (10 mg/kg IP) was used in Wistar rats chronically implanted with stainless steel electrodes. Inhibition was evaluated by paired-pulse orthodromic stimulation in Stratum Radiatum (SR) in freely behaving animals, and the EEG was recorded through the same electrodes while the rats were placed in passive rotation to induce a theta rhythm. After the application of Baclofen a reduction in the fast evokable inhibition was apparent with a simultaneous increase in theta activity, and in the amplitude of the field potentials. The effectiveness of Baclofen injection was evaluated by the degree of motor paralysis produced. No changes were apparent after saline injection. Conclusions: Baclofen produces a decrease in fast recurrent inhibition in CAI area and an increase in the theta rhythm, in freely behaving rats. These actions can have important consequences in the activity of the local networks of the hippocampus.
REVERSIBILITY OF NEUROPHYSIOLOGICAL ABNORMALITIES IN TRANSPLANTED DIABETIC RATS
G. Pozzessere 1,2, E. Valle 1.2 C. D'Alessio 1.2, G. Soldati 1,2, S. Morano 3, M. Sensi 3, U. Di Mario 4. l LR.C.C.S. lstituto Neurologico Mediterraneo,
Pozzilli (IS), Italy; z lstituto di Clinica delle Malattie Nervose e Mentali, Italy; 3 2a Clinica Medica, Universita' "La Sapienza", Roma, Italy; 4 Dipartimento di Medicina Sperimentale, Universita' di Catanzaro, Italy To verify whether pancreatic islet transplantation could reverse diabetic neurophysiological alterations, we used an experimental model in which pancreatic islets were transplanted in diabetic inbred Lewis rats. VEPs, BAEPs, SEPs and metabolic parameters were evaluated in streptozotocindiabetic rats transplanted 4 months after diabetes induction (No. 7), in diabetic rats (No. 16) and in non-diabetic control rats (No. 12). Glycemic levels were normalized by transplantation. Neurophysiological values were altered in diabetic animals before transplantation, while they improved with a detectable gradient from the peripheral to the central structures, after transplantation. SEPs were significantly improved in the tarsus-L6 and in the L6-cortex tracts (p < 0.005 and p < 0.05, respectively, vs. diabetic rats) and were unchanged in the T6-cortex tract. BAEP latency values tended to improve in transplanted rats, but the differences vs. non-transplanted diabetic animals failed to reach significance. VEP values remained clearly pathological and even deteriorated after transplantation. These results show that normalization of metabolic control by pancreatic islet transplantation can reverse some of the already established neurophysiological alterations at the peripheral nervous system level, whereas it does not improve those at the central nervous system level.
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THE EFFECT OF ANTIGENIC STIMULATION ON CONTENT OF NOREPINEPHRINE IN THE STOMACH OF RATS
Svetlana Stamatovi6, Anu~ka Andjelkovi6, Katica Jovanova-Ne~i6, Aria Laban i. Immunology Research Center, "Branislav Jankovid",
Vojvode Stepe 458, 11221 Belgrade, Yugoslavia; t Department of Pathology, Medical Faculty, Belgrade, Yugoslavia It is well documented that the immune and sympathetic nervous system communicate directly through specific nerve connection. The stomach have noradrenergic sympathetic innervation too. This study was performed in order to investigate the effects of immunization on content of norepinephrine (NE) in the stomach of rats. The male Wistar rats (250-300 g) were immunized subcutaneously with 0.1 ml bovine serum albumin in complete Freund's adjuvant (BSA-KFA group). The sham-control animals were treated in the identical manner with saline (Sh group). The norepinephrine content in the stomach of all experimental groups was assayed by reversed phase high-performance liquid chromatography with electrochemical detection (HPLC). Level of anti-BSA antibodies and the NE content of stomach were determined on the 5th, 10th and 20th days after immunization. Anti-BSA antibody production was higher on day 10 than 5, and the highest antibody production was observed on day 20. The NE content of the stomach marked increased on day 5 and 10 in comparison with both controls (intact and sham animals). By day 20, NE content had returned to normal. Our results indicate that initial marked increase of NE content in stomach was consequence of sympathetic activation by antigens stimulation and return of NE content on normal was result of reinstated homeostasis. (Supported by The Ministry of Science and Technology, Belgrade, Serbia).
338
only, 2 - running followed by clonic, and 3 - running, clonic and tonic convulsions. Controls had no convulsions. In metaphit-treated (10 mg/kg, i.p.) group the incidence and seizure severity of convulsive responses raised progressively, reaching peak 8-10 h after metaphit administration (10/12 and 2.25 :tz 0.32) and then gradually declined until 30 h postinjection, when no animal responded. Metaphit + APH group: eight hours after metaphit (10 mg/kg, i.p.) administration, when incidence and seizure severity grade reached their maximum, only rats who had convulsions were injected with APH i.c.v. The doses of APH were: 0.01 (n = 5), 0.02 (n = 5) and 0.05 (n = 5)/zmol, all in 5/xl of saline. The dose of 0.01/zmol inhibited seizures in 4 of 5 rats, and in one rat attenuated severity grade (from 2 to 1). The dose of 0.02 #mol blocked seizures in all animals (515) one hour, while the dose of 0.05/zmol completely inhibited seizures (5/5) for 4 hours.
EFFECT OF LC STIMULATION ON RSA PHASE SHIFT OSCILLATIONS BETWEEN LEFT AND RIGHT HIPPOCAMPUS IN RAT
A. Kalauzi i, M. Culic 2, B. Jankovic I, j. Saponjic 2, S. Popovic 2, M. Jankovic 2. t Center for Multidisciplinat 3, studies, Belgrade,
Yugoslavia: 2 Institute for Biological Research, Belgrade, Yugoslavia As reported earlier, rhythmic slow activity (RSA) in rat recorded from left and right hippocampus show very low frequency (< 0.5 Hz) phase shift oscillations. The aim of this study was to test the effect of locus coeruleus (LC) stimulation on these oscillations. The adult Wistar rats were implanted with bipolar stainless steel electrodes for chronic recording of RSA in dorsal hippocampi at stereotaxic coordinates: P: 2.8; L/R: 1.5; H: -2.9, and for electric stimulation of left LC: P: 9.8; L: 1.2; H: -6.5. Signals were treated as amplitude modulated theta carrier frequency oscillations. Carrier frequency phase shifts (CFPS) were calculated from theta band Fourier components. CFPS time dependence was obtained using 16 sec moving window through epochs of 64 seconds. CFPS oscillations before and immediately after short lasting LC stimulation were compared both in time and frequency domain. In most cases the stimulation of LC resulted in reduction of amplitudes of CFPS oscillations.
BACLOFEN DECREASES RECURRENT INHIBITION AND INCREASES THE THETA RHYTHM IN FREELY BEHAVING RATS
A.J.R. Leal, E. Moller, W.J. Wadman. HEM, Lisboa, Portugal; UvA,
Amsterdam, The Netherlands GABA-B receptors have been demonstrated to modulate synaptic transmission and the filtering properties in the hippocampus, and suggested to play an important role in its information processing role. In order to study the effects of GABA-B receptor stimulation in the CA 1 area of the hippocampus in vivo, Baclofen (10 mg/kg IP) was used in Wistar rats chronically implanted with stainless steel electrodes. Inhibition was evaluated by paired-pulse orthodromic stimulation in Stratum Radiatum (SR) in freely behaving animals, and the EEG was recorded through the same electrodes while the rats were placed in passive rotation to induce a theta rhythm. After the application of Baclofen a reduction in the fast evokable inhibition was apparent with a simultaneous increase in theta activity, and in the amplitude of the field potentials. The effectiveness of Baclofen injection was evaluated by the degree of motor paralysis produced. No changes were apparent after saline injection. Conclusions: Baclofen produces a decrease in fast recurrent inhibition in CAI area and an increase in the theta rhythm, in freely behaving rats. These actions can have important consequences in the activity of the local networks of the hippocampus.
REVERSIBILITY OF NEUROPHYSIOLOGICAL ABNORMALITIES IN TRANSPLANTED DIABETIC RATS
G. Pozzessere 1,2, E. Valle 1.2 C. D'Alessio 1.2, G. Soldati 1,2, S. Morano 3, M. Sensi 3, U. Di Mario 4. l LR.C.C.S. lstituto Neurologico Mediterraneo,
Pozzilli (IS), Italy; z lstituto di Clinica delle Malattie Nervose e Mentali, Italy; 3 2a Clinica Medica, Universita' "La Sapienza", Roma, Italy; 4 Dipartimento di Medicina Sperimentale, Universita' di Catanzaro, Italy To verify whether pancreatic islet transplantation could reverse diabetic neurophysiological alterations, we used an experimental model in which pancreatic islets were transplanted in diabetic inbred Lewis rats. VEPs, BAEPs, SEPs and metabolic parameters were evaluated in streptozotocindiabetic rats transplanted 4 months after diabetes induction (No. 7), in diabetic rats (No. 16) and in non-diabetic control rats (No. 12). Glycemic levels were normalized by transplantation. Neurophysiological values were altered in diabetic animals before transplantation, while they improved with a detectable gradient from the peripheral to the central structures, after transplantation. SEPs were significantly improved in the tarsus-L6 and in the L6-cortex tracts (p < 0.005 and p < 0.05, respectively, vs. diabetic rats) and were unchanged in the T6-cortex tract. BAEP latency values tended to improve in transplanted rats, but the differences vs. non-transplanted diabetic animals failed to reach significance. VEP values remained clearly pathological and even deteriorated after transplantation. These results show that normalization of metabolic control by pancreatic islet transplantation can reverse some of the already established neurophysiological alterations at the peripheral nervous system level, whereas it does not improve those at the central nervous system level.
~ ' ~
THE EFFECT OF ANTIGENIC STIMULATION ON CONTENT OF NOREPINEPHRINE IN THE STOMACH OF RATS
Svetlana Stamatovi6, Anu~ka Andjelkovi6, Katica Jovanova-Ne~i6, Aria Laban i. Immunology Research Center, "Branislav Jankovid",
Vojvode Stepe 458, 11221 Belgrade, Yugoslavia; t Department of Pathology, Medical Faculty, Belgrade, Yugoslavia It is well documented that the immune and sympathetic nervous system communicate directly through specific nerve connection. The stomach have noradrenergic sympathetic innervation too. This study was performed in order to investigate the effects of immunization on content of norepinephrine (NE) in the stomach of rats. The male Wistar rats (250-300 g) were immunized subcutaneously with 0.1 ml bovine serum albumin in complete Freund's adjuvant (BSA-KFA group). The sham-control animals were treated in the identical manner with saline (Sh group). The norepinephrine content in the stomach of all experimental groups was assayed by reversed phase high-performance liquid chromatography with electrochemical detection (HPLC). Level of anti-BSA antibodies and the NE content of stomach were determined on the 5th, 10th and 20th days after immunization. Anti-BSA antibody production was higher on day 10 than 5, and the highest antibody production was observed on day 20. The NE content of the stomach marked increased on day 5 and 10 in comparison with both controls (intact and sham animals). By day 20, NE content had returned to normal. Our results indicate that initial marked increase of NE content in stomach was consequence of sympathetic activation by antigens stimulation and return of NE content on normal was result of reinstated homeostasis. (Supported by The Ministry of Science and Technology, Belgrade, Serbia).