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Behavioural, arousal and neuronal sensitisation: The comparative approach
227 BEHAVIOURAL,AROUSAL AND NEURONAL SENSITISATION: THE COMPARATIVEAPPROACH LAMING, P.R. Department of Zoology, The Queen's U n i v e r s i t y of B e l f a s t , Belfast BT7 INN, Northern Ireland Behavioural arousal to novel s t i m u l i in vertebrates is associated with
a reduction in sensory
thresholds and enhanced responsiveness. Studies on f i s h and amphibia indicate c o n s i s t e n t , coordinated changes in peripheral physiology, increases in EEG frequency and synchrony and a sustained pot e n t i a l s h i f t . These l a t t e r central responses may r e f l e c t neuronal and g l i a l events respectively which sensitise the brain during arousal. The responses of adult mammals to novel s t i m u l i are less consistent than those of j u v e n i l e s or less p h y l o g e n e t i c a l l y "advanced" vertebrates. I t is suggested that t h i s due to the increased adaptive importance of a t t e n t i o n a l responses in mammals.
SELECTIVE MODE OF ACTION OF THE DOPAMINE D-2 RECEPTORANTAGONIST SULPIRIDE IN BEHAVIOURAL PHARMACOLOGICAL MODELS LJUNGBERG, T. Dept. of Pharmacology, Karolinska I n s t i t u t e , Box 60 400, S-I04 01 Stockholm, Sweden The dopamine (DA) D-2 receptor antagonist s u l p i r i d e has in a v a r i e t y of behavioural tests been found to exert pharmacological effects r a d i c a l l y d i f f e r e n t both from classical D-2 antagonists l i k e metoclopramide and haloperidol and from the selective D-I antagonist SCH 23390. S u l p i r i d e , f o r example, antagonises DA agonist-induced locomotion more potently than DA agonist-induced stereotypes, while the reverse is true f o r haloperidol and metoclopramide. S u l p i r i d e has f u r t h e r been found not to attenuate operant behaviours, while both the D-2 antagonists haloperidol and metoclopramide and the D-I antagonist SCH 23390 do. S u l p i r i d e has also been found to exert selective effects in tests thought to r e f l e c t DA autoreceptor a c t i v i t y , 23390 are not s e l e c t i v e .
models in which metoclopramide, haloperidol or SCH
These behavioural pharmacological results are discussed in r e l a t i o n to c l i n i c a l data and to the c u r r e n t l y accepted view of DA receptor c l a s s i f i c a t i o n .
PASSIVE AND ACTIVE AVOIDANCE LEARNING IN HOMOZYGOUSAND HETEROZYGOUSDIABETES INSIPIDUS RATS (BRATTLEBORO STRAIN) AMBROGI LORENZINI, C., BUCHERELLI, C., GIACHETTI, A. AND TASSONI, G. Dipartimento di Scienze F i s i o l o g i c h e , Viale Morgagni 63, 50134 Firenze, I t a l y Passive and active avoidance learning was investigated in male naive homozygous (HODI) and heterozygous (HEDI) diabetes insipidus Brattleboro r a t s , aged 70-80 days. A c q u i s i t i o n (7 days) and retention (7 days) of both responses were studied using the l i g h t - d a r k box paradigm. The subjects (Ss) underwent single d a i l y consecutive t r i a l s .
20 HODI and 20 HEDI Ss were divided respectively in two
equal groups, subjected e i t h e r to 0.6 or to 2 mA footshocks. Starting from the l i g h t chamber, during
a reduction in sensory
thresholds and enhanced responsiveness. Studies on f i s h and amphibia indicate c o n s i s t e n t , coordinated changes in peripheral physiology, increases in EEG frequency and synchrony and a sustained pot e n t i a l s h i f t . These l a t t e r central responses may r e f l e c t neuronal and g l i a l events respectively which sensitise the brain during arousal. The responses of adult mammals to novel s t i m u l i are less consistent than those of j u v e n i l e s or less p h y l o g e n e t i c a l l y "advanced" vertebrates. I t is suggested that t h i s due to the increased adaptive importance of a t t e n t i o n a l responses in mammals.
SELECTIVE MODE OF ACTION OF THE DOPAMINE D-2 RECEPTORANTAGONIST SULPIRIDE IN BEHAVIOURAL PHARMACOLOGICAL MODELS LJUNGBERG, T. Dept. of Pharmacology, Karolinska I n s t i t u t e , Box 60 400, S-I04 01 Stockholm, Sweden The dopamine (DA) D-2 receptor antagonist s u l p i r i d e has in a v a r i e t y of behavioural tests been found to exert pharmacological effects r a d i c a l l y d i f f e r e n t both from classical D-2 antagonists l i k e metoclopramide and haloperidol and from the selective D-I antagonist SCH 23390. S u l p i r i d e , f o r example, antagonises DA agonist-induced locomotion more potently than DA agonist-induced stereotypes, while the reverse is true f o r haloperidol and metoclopramide. S u l p i r i d e has f u r t h e r been found not to attenuate operant behaviours, while both the D-2 antagonists haloperidol and metoclopramide and the D-I antagonist SCH 23390 do. S u l p i r i d e has also been found to exert selective effects in tests thought to r e f l e c t DA autoreceptor a c t i v i t y , 23390 are not s e l e c t i v e .
models in which metoclopramide, haloperidol or SCH
These behavioural pharmacological results are discussed in r e l a t i o n to c l i n i c a l data and to the c u r r e n t l y accepted view of DA receptor c l a s s i f i c a t i o n .
PASSIVE AND ACTIVE AVOIDANCE LEARNING IN HOMOZYGOUSAND HETEROZYGOUSDIABETES INSIPIDUS RATS (BRATTLEBORO STRAIN) AMBROGI LORENZINI, C., BUCHERELLI, C., GIACHETTI, A. AND TASSONI, G. Dipartimento di Scienze F i s i o l o g i c h e , Viale Morgagni 63, 50134 Firenze, I t a l y Passive and active avoidance learning was investigated in male naive homozygous (HODI) and heterozygous (HEDI) diabetes insipidus Brattleboro r a t s , aged 70-80 days. A c q u i s i t i o n (7 days) and retention (7 days) of both responses were studied using the l i g h t - d a r k box paradigm. The subjects (Ss) underwent single d a i l y consecutive t r i a l s .
20 HODI and 20 HEDI Ss were divided respectively in two
equal groups, subjected e i t h e r to 0.6 or to 2 mA footshocks. Starting from the l i g h t chamber, during