Dose
effects of chlordiazepoxide upon habituation of open-field behavior
in white rats
S. Fukuda & S. Iwahara |
Naive
male rats were observed for 10 min in an open field for 5 successive
days. For the first 4 flays, i.p. injections were made with either
S (saline) or D (chlordiazepoxide at 10, 20 or 40 mg/2 ml/kg) 30
min prior to observation and on the following 2 days, the S rats
were treated with either S or D (at one of the 3 doses), while the
D rats with either D (at the same dose) or S. The drug-state changes
(both from S to D and D to S) increased ambulation and rearing in
the open field with D at 10 mg/kg, but at higher doses the same effect
was found only from D to S probably because of the drug's stronger
muscle relaxant action. The same "dishabituation" effect
was observed in terms of defecation and urination with the D-to-S
shift but not with the reverse shift probably because of the drug's
depressant effect upon defecation and urination; in addition the
dose-response relationship failed to appear as in ambulation and
rearing. Correlations between the 2 skeletal measures and the 2 autonomic
measures were very low.
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