Non-NMDA and NMDA receptors in the synaptic pathway between area postrema and nucleus tractus solitarius
Non-NMDA and NMDA receptors in the synaptic pathway between area postrema and nucleus tractus solitarius
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DOI：
10.1152/ajpheart.1998.275.4.h1236
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发表时间：
1998-10-01
影响因子：
4.8
通讯作者：
Bonham, AC
中科院分区：
文献类型：
--
作者：
Aylwin, ML;Horowitz, JM;Bonham, AC
静息区（AP）通过对孤束核（NTS）神经元的兴奋性投射来调节心血管功能，孤束核也通过孤立束（TS）处理初级感觉（包括心血管相关）输入。AP-NTS通路中的神经递质及其受体尚未完全表征。我们在电压和电流钳模式下对大鼠脑干片进行全细胞记录，以检验嗜离子性谷氨酸受体和α(2)-肾上腺素能受体在AP到NTS神经元通过TS接收内脏传入信息的通路中的作用。在-100到+80 mV的电位下，AP刺激（0.2 Hz）引起兴奋性突触后电流，其快速成分被非n-甲基- d -天冬氨酸（NMDA）受体拮抗剂阻断1,2,3,4-四氢-6-硝基-2,3-二氧苯并-喹啉-7-磺酰胺（NBQX; 3 μ M, n = 7）和一个被NMDA受体拮抗剂dl -2-氨基-5-磷酸戊酸（APV; 50 μ M, n = 8）阻断的缓慢组分。NBQX （3 μ M, n = 14）可消除ap诱发的动作电位，而APV （50 μ M, n = 9或500 μ M， n = 6）和育亨宾（200 μ M, n = 5或2 μ M， n = 10）则无此作用。因此，尽管AP刺激激活了接受TS输入的NTS神经元上的非NMDA和NMDA受体，但突触传递只需要非NMDA受体。
Area postrema (AP) modulates cardiovascular function through excitatory projections to neurons in nucleus tractus solitarius (NTS), which also process primary sensory (including cardiovascular-related) input via the solitary tract (TS). The neurotransmitter(s) and their receptors in the AP-NTS pathway have not been fully characterized. We used whole cell recordings in voltage- and current-clamp modes in the rat brain stem slice to examine the role of ionotropic glutamatergic receptors and alpha(2)-adrenergic receptors in the pathway from AP to NTS neurons receiving visceral afferent information via the TS. In neurons voltage clamped at potentials from -100 to +80 mV,AP stimulation (0.2 Hz) evoked excitatory postsynaptic currents having a fast component blocked by the non-N-methyl-D-aspartate (NMDA) receptor antagonist 1,2,3,4-tetrahydro-6-nitro-2,3-dioxobenzo- quinoxaline-7-sulfonamide (NBQX; 3 mu M, n = 7) and a slow component blocked by the NMDA receptor antagonist DL-2-amino-5-phosphonovaleric acid (APV; 50 mu M, n = 8). Although NBQX (3 mu M, n = 14) abolished AP-evoked action potentials, APV (50 mu M, n = 9 or 500 mu M, n = 6) or yohimbine, (200 nM, n = 5 or 2 mu M, n = 10) did not. Thus, although AP stimulation activates both non-NMDA and NMDA receptors on NTS neurons receiving TS input, only non-NMDA receptors are required for synaptic transmission.