Nettles K W, Pesold C, Goldman M B
Department of Psychiatry, University of Chicago, IL 60637, USA.
Brain Res. 2000 Mar 6;858(1):181-90. doi: 10.1016/s0006-8993(99)02281-7.
The ventral hippocampal formation (vHF) seems to constrain diverse responses to psychological stimuli, and disruption of this function may underlie severe neuropsychiatric diseases. In particular, the ventral subiculum inhibits hypothalamic-pituitary-adrenal axis (HPA) activity following psychological, but not systemic, stressors. Despite the difficulty in interpreting such HPA responses, they have been relied upon to further characterize vHF function, because increased HPA axis activity is implicated in neuropsychiatric disturbances, and reliance on behavioral and cognitive data is even more problematic. Plasma arginine vasopressin (pAVP), which is inhibited by psychological stimuli and is also implicated in diverse neuropsychiatric diseases, provides a less ambiguous measure of CNS function. To test if its inhibition by psychological stress is also mediated by the vHF, we conducted two studies. In the first, pAVP and behavioral responses to novel acoustic stress were assessed in rats with bilateral excitotoxic lesions of the ventral subiculum and the ventral hippocampus. The subiculum lesions blocked the fall in pAVP and enhanced escape behaviors, whereas the hippocampal lesions produced responses intermediate to those in the subiculum-lesioned and control rats. In the second study, the pAVP response was similarly blocked by small lesions restricted to those vHF subfields which project to the neuroendocrine hypothalamus, compared to the response in animals with lesions in other vHF subfields. These results indicate that discrete projections from the vHF inhibit the pAVP response to psychological stimuli, and suggest that pAVP may provide a reliable probe of vHF activity.
腹侧海马结构（vHF）似乎对心理刺激的多种反应具有抑制作用，该功能的破坏可能是严重神经精神疾病的基础。特别是，腹侧下托在心理应激源（而非全身性应激源）作用后会抑制下丘脑-垂体-肾上腺轴（HPA）的活动。尽管解读此类HPA反应存在困难，但由于HPA轴活动增加与神经精神障碍有关，且依赖行为和认知数据存在更多问题，因此一直依靠这些反应来进一步描述vHF的功能。血浆精氨酸加压素（pAVP）受心理刺激抑制，也与多种神经精神疾病有关，它为中枢神经系统功能提供了一个较明确的测量指标。为了测试心理应激对其的抑制作用是否也由vHF介导，我们进行了两项研究。在第一项研究中，评估了腹侧下托和腹侧海马双侧兴奋性毒性损伤大鼠对新声音应激的pAVP和行为反应。下托损伤阻止了pAVP的下降并增强了逃避行为，而海马损伤产生的反应介于下托损伤大鼠和对照大鼠之间。在第二项研究中，与其他vHF亚区有损伤的动物相比，仅限于投射到神经内分泌下丘脑的vHF亚区的小损伤同样阻断了pAVP反应。这些结果表明，vHF的离散投射抑制了pAVP对心理刺激的反应，并提示pAVP可能为vHF活动提供可靠的检测指标。
