Ethanol and physostigmine effects on open field behavior in Wistar rats

The paper is aimed at the evaluation the effect of relatively low doses of ethanol and physostigmine salicylate on behavior of the male Wistar rat in an open field test. Both drugs were administered as a solution intragastrically 1 hour before the test started in dose ranges of 0.6-1.8 g/kg and 0.06-0.18 mg/kg, respectively. Lower doses of ethanol showed dose dependent biphasic effect on the ambulation and grooming time in animals. The medium dose 1.2 g/kg was rather ineffective in affecting rat behavior in the hole board test. Individual variables showed different sensitivity to individual ethanol doses. But from the medium dose, individual manifestations of ataxia were observed. Using the dose, only total ambulation, rearing time and rear latency were not affected when the rats were experienced with repeated exposure to open field arena or ethanol dose beforehand. Physostigmine alone increased defecation level significantly by two doses but lower doses changed some of the other variables, too. Combined administration of both drugs in medium doses did not affect the rat behavior considerably. The intra-trial habituation of three parameters of OF behavior seems to be influenced differently. Ethanol showed a tendency to facilitate the habituation of rearing, but rather to interfere with that of grooming. The later effect was also shown for physostigmine 0.12 mg/kg. The experimental part of the paper is supplied by the discussion of aspects important for modulation of rodent behavior in an open field test.