Hyponeophagia and arousal in rats: effects of diazepam, 5-methoxy-N,N-dimethyltryptamine, d-amphetamine and food deprivation.
Psychopharmacology January 1, 1982 DOI: 10.1007/BF00433744
Summary
Diazepam significantly reduces anxiety-like behavior in rats, with doses of 0.3 to 3.0 mg/kg showing effective results. In a study involving both acute and chronic administration, 10 mg/kg led to sedation and variability, while lower doses maintained consistent anxiolytic effects. Increased food deprivation did not replicate benzodiazepine effects and actually delayed eating in rats given another compound. Notably, the sedative effects of high-dose diazepam were counteracted by d-amphetamine, highlighting a complex interaction between arousal and anxiety responses.
Abstract
A modified hyponeophagia test is described as an animal model of anxiety. The effects of 0, 0.3, 1.0, 3.0 and 10 mg/kg diazepam, given both acutely and for 7 days pretest, were assessed in rats. Acutely, diazepam reduced hyponeophagia over the dose range 0.3-3.0 mg/kg but 10.0 mg/kg produced sedation and large variability. Chronically, the dose-response relationships were monotonic and the maximal effect was increased, suggesting that differential tolerance occurs to the sedative, but not to the anxiolytic, effects of this drug. Increased food deprivation did not mimic benzodiazepine effects on hyponeophagia, and actually prolonged eating latency in rats treated with 5-methoxy-N,N-dimethyltryptamine (2.5 mg/kg), which does not support an interpretation of diazepam effects in terms of appetitive actions. An arousal hypothesis of hyponeophagia was proposed and supported by the antagonism of the sedative effects of 10.0 mg/kg diazepam by d-amphetamine (0.5 mg/kg). Although both male and female rats were used throughout, sex differences were few in these studies.