ISSN:
1432-2072
Keywords:
γ-Aminobutyrate (GABA)
;
GABA and GABA agonists
;
Chlordiazepoxide
;
Amylobarbitone
;
Picrotoxin
;
Bicuculline
;
β-Carbolines
;
Muscimol
;
Baclofen
;
Punished barpressing
;
Anxiety
;
Rat
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Rats were trained to press a bar for sucrose reward on a random-interval (RI) schedule and footshock punishment was then introduced for 3-min intrusion periods (signalled by a tone) on an independent RI schedule. Shock intensity was individually adjusted to produce stable intermediate levels of response suppression during the tone for each animal. Groups of animals were then allocated to a number of separate experiments in which they were systemically injected with anxiolytics (chlordiazepoxide HCl or sodium amylobarbitone), GABA antagonists (picrotoxin or bicuculline), the GABAA agonist muscimol, the GABAB agonist baclofen, an antagonist (RO 15-1788) at the benzodiazepine receptor and, an inverse agonist (FG 7142) at this receptor. The results showed that the alleviation of punishment-induced suppression of barpressing produced by chlordiazepoxide was blocked or partially blocked by RO 15-1788, picrotoxin and bicuculline but not by FG 7142; that picrotoxin (but not FG 7142) increased the suppression of responding by punishment; that neither muscimol nor baclofen affected responding on their own, but their combination weakly but reliably released punished responding from suppression; and that the anti-punishment effect of amylobarbitone was unaffected by either picrotoxin or bicuculline, though the barbiturate reversed the punishment-enhancing effect of picrotoxin. These results are discussed in the light of the hypothesis that anxiolytic behavioural effects are due to increased GABAergic inhibition.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00428424
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