Auer R N, Jensen M L, Whishaw I Q
Neuroscience Research Group, University of Calgary, Alberta, Canada.
J Neurosci. 1989 May;9(5):1641-7. doi: 10.1523/JNEUROSCI.09-05-01641.1989.
It is well known that ischemia causes neuronal necrosis in selectively vulnerable sectors of the hippocampus. Since the hippocampus is involved in spatial navigation, learning, and memory, selective deficits in these areas may arise from ischemic brain damage. The objective of this study was to test whether a minimal ischemic insult, producing selective neuronal necrosis restricted to only a portion of the CA1 pyramidal cells of the hippocampus, could produce a detectable spatial navigation deficit. Male Wistar rats received 9 min of forebrain ischemia induced by carotid clamping and hypotension or sham operation with exposure of the carotid arteries. The rats were allowed to recover and were tested on a simple place task, a place learning-set task, and a pattern discrimination task in swimming pools paradigms. Subsequently, the rats were perfusion-fixed and their entire brains subjected to quantitative histopathologic analysis. Although both ischemic and sham-operated groups learned the simple place task, the learning-set task revealed defects in spatial navigation, reflected as increased errors and latency in the performance of the ischemic rats. In the subsequent pattern discrimination task, the ischemic group was superior to the control group, which perseverated by attempting to use a place strategy to solve the discrimination. Quantitative neuropathology revealed neuronal necrosis in the ischemia group limited to 50% of the CA1 zone of the hippocampus. Extrahippocampal damage consisted of rare cortical neuronal necrosis in 2 of 6 animals.(ABSTRACT TRUNCATED AT 250 WORDS)
众所周知，缺血会导致海马体选择性易损区域的神经元坏死。由于海马体参与空间导航、学习和记忆，这些区域的选择性缺陷可能源于缺血性脑损伤。本研究的目的是测试一种最小限度的缺血性损伤，即仅导致海马体CA1锥体细胞一部分发生选择性神经元坏死，是否会产生可检测到的空间导航缺陷。雄性Wistar大鼠接受9分钟的颈动脉夹闭和低血压诱导的前脑缺血或暴露颈动脉的假手术。让大鼠恢复后，在游泳池范式中对其进行简单位置任务、位置学习集任务和模式辨别任务测试。随后，对大鼠进行灌注固定，并对其全脑进行定量组织病理学分析。尽管缺血组和假手术组都学会了简单位置任务，但学习集任务显示出缺血大鼠在空间导航方面存在缺陷，表现为执行任务时错误增加和潜伏期延长。在随后的模式辨别任务中，缺血组优于对照组，对照组因试图使用位置策略解决辨别问题而出现持续性错误。定量神经病理学显示，缺血组的神经元坏死仅限于海马体CA1区的50%。海马体外损伤包括6只动物中有2只出现罕见的皮质神经元坏死。（摘要截断于250字）
