Effects of 5-HT and Norepinephrine on the Neuronal Activities of the Nucleus Tractus Solitaril in Medullary Slices / 第二军医大学学报

ABSTRACT

The relationship between 5-HT receptor and a-adrenoceptor was investigated in rat medullary slice preparations. In 57 nucleus tractus solitarii (NTS) neurons, 47 (82.5%) responded to both serotonin (5-HT) and norepinephrine (NE). After synapse transmission was blocked by perfusion of artificial cerebrospinal fluid (ACSF) with low calcium and high magnesium, 5 in 8 neurons were still sensitive to both 5-HT and NE. On the other hand, 3 in 5 neurons responding only to 5-HT or NA were sensitive to both 5-HT and NE after the synapse transmission blockage. In some neurons which exhibited excitatory or inhibitory responses to 5-HT or NE alone, the responses were inversed when perfused with 5-HT and NE in combination. These results suggest that there may exist an inhibitory interaction between 5-HT receptors and a-adrenoceptors in NTS and that most 5-NT and a-adrenoceptors coexist in the same NTS neurons.