흰쥐 뇌에서 Diazepam이 Haloperidol에 의한 DOPAC 증가에 미치는 영향

Effect of Diazepam on Haloperidol-Induced DOPAC Increase in the Rat Brain

The effects of diazepam on halopridol-induced DOPAC increase in the caudate-putamen and frontal cortex of the rat brain were studied. There were significant differences in the degree of DOPAC increase after haloperidol administration between the caudate-putamen and frontal cortex. While the dose responses of DOPAC increase revealed a similar trend between two regions at the haloperidol dose of 0.05mg/kg, the DOPAC increase was much higher in the caudate-putamen than in the frontal cortex at the haloperidol doses of 0.5mg/kg and 5mg/kg. After the single administration of diazepam 5mg/kg or lOmg/kg, there was no significant decrease of DOPAC levels in both regions. On the other hand the pretreatment of diazepam in doses of 5mg/kg or lOmg/kg blunted haloperidol-induced increase of DOPAC levels in the caudateputamen and in the frontal cortex to lesser degree. These results not only support the previous findings that diazepam blunted antipsychoticinduced D A metabolism in the striatum but also suggest that diazepam modulate antipsychoticinduced DA metabolism in the frontal cortex too. However, it is unlikely that there exists a feedback interaction between GABA neurons in the frontal cortex and DA neurons in the ventral tegmental area.