Departamento de Psicobiologia, Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
Behav Brain Res. 2012 May 16;231(1):97-104. doi: 10.1016/j.bbr.2012.02.041. Epub 2012 Mar 3.
Rats with a neonatal ventral hippocampal lesion (NVHL) have been used to model certain features of schizophrenia because they display dopaminergic activity and behavioral alterations consistent with a dysfunctional prefrontal cortex after puberty. Microdialysis studies in normal rats demonstrated increased prefrontal dopamine release during the incentive phase of behavior in an experimental situation specifically designed to evidence this behavioral aspect: the so called "sensory-specific satiety" procedure. Our hypothesis is that if dopaminergic activity in the prefrontal cortex of NVHL rats differs from sham lesioned rats, the responsiveness to the aforementioned experimental situation should also be different. Extracellular medial prefrontal dopamine outflow increased in hungry control rats when they had access to food and decreased across satiety. It increased again when a new food was presented, even when the rats were satiated. NVHL rats also had increased dopamine prefrontal outflow in these conditions, but it remained high after the end of the consumption period. The food consumption behavior declined less rapidly and the reinstatement of food consumption, usually produced by new food, did not occur in NVHL rats, provided the lesions were large. These data were discussed in relation to several theoretical backgrounds developed about the incentive aspect of behavior and for understanding the pathophysiology of schizophrenia.
新生大鼠海马腹侧区损伤（NVHL）模型被用于模拟精神分裂症的某些特征，因为它们在青春期后表现出多巴胺能活性和行为改变，与前额叶皮层功能障碍一致。在正常大鼠的微透析研究中，在专门设计的实验情况下，即所谓的“感觉特异性饱足”程序中，在行为的激励阶段，前额叶多巴胺释放增加。我们的假设是，如果 NVHL 大鼠前额叶皮层中的多巴胺能活性与假损伤大鼠不同，那么对上述实验情况的反应也应该不同。当饥饿的对照大鼠可以接触到食物时，其内侧前额叶多巴胺外流增加，而在饱足时则减少。当呈现新食物时，它再次增加，即使大鼠已经饱足。在这些情况下，NVHL 大鼠的前额叶多巴胺外流也增加，但在消耗期结束后仍然很高。NVHL 大鼠的食物消耗行为下降速度较慢，并且通常由新食物引起的食物消耗的恢复不会发生，前提是损伤较大。这些数据与关于行为激励方面和理解精神分裂症病理生理学的几个理论背景进行了讨论。
