Travis K A, Boulant J A
Department of Physiology, College of Medicine, Ohio State University, Columbus 43210.
Am J Physiol. 1990 Jan;258(1 Pt 2):R175-81. doi: 10.1152/ajpregu.1990.258.1.R175.
Single-unit activity was recorded in hypothalamic tissue slices from spontaneously hypertensive (SH) and normotensive Wistar-Kyoto (WKY) rats to identify differences in neuronal osmosensitivity between these two strains. Neurons were characterized according to location, firing rate, temperature sensitivity, and response to hyposmotic (280 mosmol/kgH2O) and hyperosmotic (320 mosmol/kgH2O) media. More than half of the thermosensitive neurons were also osmosensitive. Three groups of osmosensitive neurons were identified: 1) low-firing neurons excited by hyposmolality and inhibited by hyperosmolality, 2) high-firing neurons excited by hyposmolality, and 3) high-firing neurons excited by hyperosmolality. There were no differences between strains in terms of the proportions of osmosensitive neurons. Compared with WKY neurons, however, SH osmosensitive neurons displayed reduced sensitivity to hyperosmotic media. Also, SH osmotically insensitive neurons displayed lower spontaneous firing rates. These differences in osmosensitivity and spontaneous activity may provide a neuronal basis to explain some of the differences in water and sodium regulation observed in hypertensive rats.
记录自发性高血压（SH）大鼠和正常血压的Wistar-Kyoto（WKY）大鼠下丘脑组织切片中的单单位活动，以确定这两种品系神经元渗透敏感性的差异。根据神经元的位置、放电频率、温度敏感性以及对低渗（280 mosmol/kgH2O）和高渗（320 mosmol/kgH2O）介质的反应对其进行表征。超过一半的热敏神经元也是渗透敏感的。确定了三组渗透敏感神经元：1）低放电神经元，受低渗刺激兴奋，受高渗抑制；2）高放电神经元，受低渗刺激兴奋；3）高放电神经元，受高渗刺激兴奋。在渗透敏感神经元的比例方面，品系之间没有差异。然而，与WKY神经元相比，SH渗透敏感神经元对高渗介质的敏感性降低。此外，SH渗透不敏感神经元的自发放电频率较低。这些渗透敏感性和自发活动的差异可能为解释高血压大鼠中观察到的水和钠调节差异提供神经元基础。
