Central Dopamine Turnover in Guinea Pig Pups During Separation From Their Mothers in a Novel Environment

Guinea pig pups that were separated from their mothers and placed into a novel environment for 90 min showed an increase in dopamine (DA) turnover (ratio of metabolites to DA) in the septum compared with undisturbed baseline controls. Pups placed into the novel environment with their mothers exhibited an intermediate level of DA turnover. After 24 hr of separation in the novel environment, pups’ DA turnover in the septum had returned to the baseline level. DA turnover in the caudate nucleus was unaffected by these procedures. Also, turnover in both septum and caudate nucleus when pups were not separated was positively correlated with the number of vocalizations emitted during 30 min of separation. These results closely parallel findings in separated monkeys and indicate that the guinea pig represents a useful rodent model for studying such effects. That elevated DA turnover during separation occurred in the septum suggests involvement of the mesolimbic system.