Nilsson L, Mohammed A K, Henriksson B G, Winblad B, Bergström L
Department of Clinical Neuroscience and Family Medicine, Alzheimer's Disease Research Center, Karolinska Institutet, Huddinge University Hospital, Sweden.
Regul Pept. 1995 Jul 21;58(1-2):11-8. doi: 10.1016/0167-0115(95)00053-e.
We have previously reported increased somatostatin levels in the cerebral cortex of rats housed in impoverished environment and subsequently subjected to a behavioural testing procedure, consisting of open-field exposure and spatial learning. The aim of the present study was to evaluate the degree of neurochemical specificity of the activation of somatostatin neurotransmission and to examine whether the altered levels were due to learning stimulation. Adult rats, previously housed individually for 30 days, were exposed to repeated sessions of a spatial learning task (2 days or 14 days) or repeated sessions of free swimming (14 days). The training sessions of the 14 day group consisted in recurrently changed position of the platform in a learning-set paradigm. Our data showed increased somatostatin immunoreactivity, and unchanged substance P immunoreactivity in the posterior part of the cerebral cortex. However, somatostatin levels increased to a similar extent following 14 days of repeated spatial learning sessions as free swimming sessions. We conclude that the activity of the cortical somatostatin system appears to be sensitive to environmentally induced sensorimotor stimulation in general, rather than learning per se. Thus, external stimulation of early clinical dementia patients with preserved sensorimotor receptivity, in an attempt to restore cognitive function, might be associated with altered somatostatin levels.
我们之前报道过，饲养在贫困环境中并随后接受行为测试程序（包括旷场暴露和空间学习）的大鼠，其大脑皮层中生长抑素水平升高。本研究的目的是评估生长抑素神经传递激活的神经化学特异性程度，并检查水平的改变是否是由于学习刺激所致。成年大鼠，先前单独饲养30天，接受重复的空间学习任务训练（2天或14天）或重复的自由游泳训练（14天）。14天组的训练课程包括在学习集范式中反复改变平台的位置。我们的数据显示，大脑皮层后部生长抑素免疫反应性增加，而P物质免疫反应性未改变。然而，经过14天的重复空间学习训练和自由游泳训练后，生长抑素水平升高的程度相似。我们得出结论，一般来说，皮层生长抑素系统的活性似乎对环境诱导的感觉运动刺激敏感，而不是对学习本身敏感。因此，对具有保留的感觉运动接受能力的早期临床痴呆患者进行外部刺激，试图恢复认知功能，可能与生长抑素水平改变有关。
