Twery M J, Moss R L
Peptides. 1985 May-Jun;6(3):373-8. doi: 10.1016/0196-9781(85)90098-1.
Individual neurons in the hypothalamus, thalamus, cortex, and other forebrain areas of urethane-anesthetized, male rats were iontophoretically tested for their membrane sensitivity to salmon calcitonin (CT), human CT, and CT gene-related peptide (CGRP). Extracellular recording of unit activity revealed that depression of neuronal firing was the predominant effect of iontophoretically applied salmon CT (35 of 74 cells tested). Few neurons responded to salmon CT with an increase in firing rate (N = 3). When CGRP was iontophoretically applied a pattern of response resembling that of salmon CT was observed. CGRP was predominantly inhibitory and excited those neurons whose firing rate was increased by salmon CT. Inhibition was also the predominant effect of human CT. However, no neurons were excited by human CT. The results clearly demonstrate that a subpopulation of neurons with membrane sensitivity to salmon CT, human CT, and CGRP are present in the rat forebrain. This finding suggests that modulation of neuronal activity may underlie the behavioral and biochemical effects of these peptides when administered centrally. Endogenous CGRP and CT-like peptides in rat brain may be capable of regulating these events as neurotransmitters or neuromodulators.
对用氨基甲酸乙酯麻醉的雄性大鼠的下丘脑、丘脑、皮质及其他前脑区域的单个神经元进行离子导入测试，检测其对鲑鱼降钙素（CT）、人降钙素和降钙素基因相关肽（CGRP）的膜敏感性。单位活动的细胞外记录显示，离子导入鲑鱼降钙素的主要效应是抑制神经元放电（74个测试细胞中有35个）。很少有神经元对鲑鱼降钙素的反应是放电频率增加（N = 3）。当离子导入CGRP时，观察到一种类似于鲑鱼降钙素的反应模式。CGRP主要起抑制作用，并能兴奋那些因鲑鱼降钙素而放电频率增加的神经元。抑制也是人降钙素的主要效应。然而，没有人降钙素能兴奋神经元。结果清楚地表明，大鼠前脑中存在对鲑鱼降钙素、人降钙素和CGRP具有膜敏感性的神经元亚群。这一发现表明，当这些肽在中枢给药时，神经元活动的调节可能是这些肽行为和生化效应的基础。大鼠脑中内源性CGRP和CT样肽可能能够作为神经递质或神经调节剂调节这些事件。
