Abstract: The present study investigated the effects of pubertal and adult social isolation on latent inhibition of rats and explored its dopamine substrate. In experiment 1, Wistar male rats were given 14 days isolated rearing during their puberty (PND38-51), then latent inhibition (LI) was tested in both adolescent and young adult rats, the results show that social isolation during peri-puberty impaired LI of young adult rats, but left LI of adolescent rats intact; In experiment 2, Wistar male rats were given 14 days isolated rearing during their puberty (PND58-71), then LI was tested at PND72 and PND86, the results show that social isolation during adult period did not affect LI of rats; In experiment 3, after the same isolation treatment like experiment 1, dopamine (DA) level in nucleus accumbens (NAc) was measured in adolescent and young adult rats, the results showed that social isolation during puberty increased the DA level of NAc in young adult rats, but not in adolescent rats. These results suggest that compared to social isolation during adult period, the expression of LI deficit induced by isolated rearing during puberty is found after a developmental delay, and DA in NAc may be involved in the neural substrate, which may mirror some aspects of the ontogency of schizophrenic symptoms.

Key words: puberty, schizophrenia, latent inhibition, dopamine (DA), nucleus accumbens (NAc)

摘要： 观察青春期和成年早期社会隔离对不同发育阶段大鼠的潜伏抑制的影响，并进一步探讨其神经机制。实验1：雄性Wistar大鼠在PND38-51天被给予2周的社会隔离，然后分别在PND52天及恢复2周群居后的PND66天，即青春期和成年早期，测定潜伏抑制；实验2：雄性Wistar大鼠在PND58-71天被给予2周的社会隔离，然后分别在PND72天及恢复2周群居后的PND86天，测定潜伏抑制；实验3：利用实验1的社会隔离模式，然后在PND52天及PND66天测定其伏隔核的多巴胺水平。实验发现：1）青春期社会隔离不影响青春期大鼠的潜伏抑制及伏隔核多巴胺水平，但能诱发成年早期大鼠的潜伏抑制缺失及伏隔核内多巴胺水平的提高；2）成年早期的社会隔离不影响大鼠的潜伏抑制。实验结果表明：与成年早期社会隔离相比，青春期社会隔离能诱发大鼠的潜伏抑制缺失，且此行为异常直至成年期后才表现出来，伏隔核的多巴胺可能和参与这一过程的神经机制相关。

关键词: 青春期, 精神分裂症, 潜伏抑制, 多巴胺, 伏隔核