Kant G J, Meyerhoff J L, Jarrard L E
Pharmacol Biochem Behav. 1984 May;20(5):793-7. doi: 10.1016/0091-3057(84)90201-6.
The response of rats with hippocampal lesions to acute and repeated footshock stress was assessed by measurement of pituitary cyclic AMP, plasma corticosterone and plasma prolactin. Levels of pituitary cyclic AMP and plasma prolactin and corticosterone were similar in never-shocked sham controls, and never-shocked hippocampal and neocortical lesion groups. Acute first time shock markedly elevated all measured stress indices with no statistically significant differences observed among surgical groups. In rats subjected to repeated stress (one 15 min footshock session per day for 10 days) and sacrificed 24 hours after the last shock session, levels of pituitary cyclic AMP and plasma hormones were similar to levels in never-shocked shams with the exception of the hippocampal animals. The rats with hippocampal lesions had higher levels of pituitary cyclic AMP, plasma corticosterone and plasma prolactin compared to never-shocked animals. We suggest that these data reflect a hyperreactive response of the hippocampal animals to a situation previously associated with shock. Finally, rats in all surgical groups subjected to repeated stress and sacrificed immediately after the last shock session showed a diminished cyclic AMP response to the stressor as compared to first footshock session response, demonstrating a habituation to the stressor as measured by this index. No differences in habituation were observed among hippocampal, neocortical and sham groups. Plasma hormone responses did not habituate in any group. These data support the behavioral observations of hyperreactivity in hippocampal animals and indicate that hippocampal animals are able to habituate to repeated stressful stimuli.
通过测量垂体环磷酸腺苷（cAMP）、血浆皮质酮和血浆催乳素来评估海马体损伤大鼠对急性和反复足部电击应激的反应。在从未接受电击的假手术对照组、从未接受电击的海马体和新皮质损伤组中，垂体cAMP、血浆催乳素和皮质酮水平相似。首次急性电击显著提高了所有测量的应激指标，各手术组之间未观察到统计学上的显著差异。在接受反复应激（每天进行一次15分钟的足部电击，持续10天）并在最后一次电击后24小时处死的大鼠中，除海马体损伤动物外，垂体cAMP和血浆激素水平与从未接受电击的假手术组相似。与从未接受电击的动物相比，海马体损伤大鼠的垂体cAMP、血浆皮质酮和血浆催乳素水平更高。我们认为，这些数据反映出海马体损伤动物对先前与电击相关的情况反应过度。最后，所有接受反复应激并在最后一次电击后立即处死的手术组大鼠，与首次足部电击时相比，对应激源的环磷酸腺苷反应减弱，表明通过该指标测量，大鼠对应激源产生了习惯化。在海马体损伤组、新皮质损伤组和假手术组之间未观察到习惯化方面的差异。任何组的血浆激素反应均未出现习惯化。这些数据支持了海马体损伤动物反应过度的行为观察结果，并表明海马体损伤动物能够对反复的应激刺激产生习惯化。
