ISSN:
1432-1912
Keywords:
Neuroleptics
;
Benzodiazepines
;
Dopamine
;
HVA
;
GABA
;
Catalepsy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Several benzodiazepines (chlordiazepoxide, clonazepam, diazepam and flunitrazepam) markedly counteracted the elevation of the homovanillic acid (HVA) content of the rat brain induced by neuroleptics (haloperidol, pimozide, chlorpromazine, and clozapine). A similar effect was obtained with the inhibitor of GABA transaminase, aminooxyacetic acid (AOAA). The interaction of benzodiazepines with the neuroleptic-induced HVA increase was similar in the striatum and in the limbic forebrain, and was antagonized by the GABA receptor-blocking agent, picrotoxin. Both the benzodiazepines used and AOAA potentiated the cataleptic effect of the four neuroleptics. It is concluded that benzodiazepines, by intensifying GABA-ergic transmission, enhance the ongoing inhibition of mesencephalic dopamine neurons exerted by the striatonigral GABA system. As a consequence, the feedback activation of dopamine neurons induced by the neuroleptic blockade of dopamine receptors in the striatum and the limbic system is attenuated. This results in a reduction of the neuroleptic-induced increase of HVA and in the potentiation of the cataleptic effect of neuroleptics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00692778
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