Chlordiazepoxide discriminates between the neural circuits mediating neuroendocrine responses to fear- and anxiety-producing stimuli in the rat.
Effects of a benzodiazepine, chlordiazepoxide (CDP), on neuroendocrine responses to emotional stimuli were studied in male rats. In the experiments with conditioned fear stimuli, rats received a pure tone paired with footshocks in the training session and were tested on the following day with the same environmental stimuli. CDP injected i.p. 30 min before training impaired the suppressive vasopressin and the augmentative oxytocin or adrenocorticotrophic hormone (ACTH) responses to the conditioned fear stimuli. However, the drug, administered 30 min after the training, did not significantly alter the hormonal responses to conditioned fear stimuli. CDP administered 30 min before testing also abolished the hormonal responses to conditioned fear stimuli. The stimuli which were identical to those used for training or unconditioned fear stimuli (intermittent footshocks) also produced the vasopressin, oxytocin and ACTH responses, and CDP prevented these hormonal responses. The drug, however, did not prevent the hormonal responses to novel environmental stimuli. Novel stimuli are known to produce a state of anxiety. Thus the present experiments demonstrate that CDP discriminates between the neural circuits mediating fear- and anxiety-producing stimuli in the rat.
Yagi
K
K
Department of Physiology, Jichi Medical School, Minamikawachi-machi, Japan.
Onaka
T
T
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D014151:Anti-Anxiety Agents; D001007:Anxiety / Q000503:physiopathology*; D002707:Chlordiazepoxide; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004777:Environment; D005239:Fear / Q000502:physiology*; D008297:Male; D009415:Nerve Net / Q000187:drug effects*; D009490:Neurosecretory Systems / Q000187:drug effects / Q000502:physiology*; D010121:Oxytocin / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D014667:Vasopressins / Q000097:blood
D014151:Anti-Anxiety Agents; D014667:Vasopressins; D010121:Oxytocin; D002707:Chlordiazepoxide; D000324:Adrenocorticotropic Hormone