地塞米松对大鼠孤束核压力感受性神经元微电泳NA/NPY所致反应的影响

实验采用多管微电泳记录神经元胞外放电技术，观察地塞米松（Ｄｅｘ）、去甲肾上腺素（ＮＡ）及神经肽Ｙ（ＮＰＹ）对孤束核（ＮＴＳ）压力感受反射性神经元的作用，以及将这些神经元用Ｄｅｘ预处理后对ＮＡ／ＮＰＹ反应的变化。向ＮＴＳ内３８个压力感受神经元微电泳Ｄｅｘ后，压力感受兴奋性神经元主要表现为抑制（８／１９），压力感受抑制性神经元则主要表现为兴奋（９／１９）。而电泳ＮＡ或ＮＰＹ，压力感受兴奋性神经性元以兴

INFLUENCE OF DEXAMETHASONE ON THE RESPONSES OF BARORECEPTIVE NEURONS IN NUCLEUS TRACTUS SOLITARIUS TO MICROIONTOPHORESIS OF NORADRENALINE/NEUROPEPTIDE Y IN RATS

The responses of a single neuron in the nucleus tractus solitarius to activation of the baroreflex and to microiontophoresis of Dex, NA or NPY were studied. Of the 75 cells studied, 19 exhibited decrease and another 19 units showed increase in firing rate in response to baroreflex activation, while the remaining 37 neurons showed no response. Microiontophoresis of Dex had exciting effect on baroreflex inhibited cells (9/19) and inhibitory effect on baroreflex excited cells (8/19). In contrast, microiontophoresis of NA or NPY showed inhibitory effect on baroreflexinhibited cells (10/19 or 13/19) and exciting effect on baroreflex excited cells (15/19 or 14/19). The responses of baroreceptive cells to microiontophoresis of NA or NPY were blocked by microiontophoresis of Dex (20/32 or 18/34). The results suggest that Dex has not only a rapid influence on the response of baroreceptive neurons in the NTS, but also a rapid modulation on the response of baroreceptive neurons in the NTS to NA/NPY.