【摘要】 在89张Sprague－Dawley大鼠延髓脑片上，用玻离微电极记录到165个延髓头端腹外侧区（RVLM）神经元的自发放电，其放电形式有三种：规则型（102个，61.8％）；不规则型（40个，24．2％）；静息型（23个，14％）。乙酰胆碱（ACh，0．1，0.3，1.0，3.0μmol／L，1～3min）对自发放电有兴奋、抑制、双相和无影响四种效应，各占所测试神经元数的41.8％，20％，3％和35．2％。兴奋效应呈剂量一反应关系。此外，观察了49例ACh对RVLM神经元的效应（兴奋效应29例，抑制效应20例），这些效应大部分被阿托品所阻断（n＝42）；ACh的兴奋效应（n＝14）大部分可被胆碱能M1受体特异性拮抗剂吡卓酮（PZ，10，30nmol／L）所拮抗（n＝9），而不被M2受体特异性拮抗剂聚亚甲基四胺（MT）和AFDX－116所拮抗；ACh的抑制效应（n＝10）大部分可被MT（10，30nmol／L）所拮抗（n＝7）；而这种抑制效应（n＝9）也可被AFDX-116（10，30nmol／L）所拮抗（n＝6），但是，ACh的这种抑制效应不能被PZ阻断。更多还原

【Abstract】 Extracellular single-unit discharges were obtained from l65 spontaneously active neurons within the region of the rostral ventrolateral medulla (RVLM ) by glass microelectrode from 89 brain slices of the SpragUe-Dawley rats. The units could be divided into three types: regular (61. 8% ), irregular (24. 2% ) and silent (14% ).Acetylcholine (ACh, 0. 1, 0.3 μmol/L) showed four kinds of effects on spontaneous discharges of RVLM neurons: excitatory, inhibitory, biphasic and non-responsive, counting respectively 41. 8%, 20%, 3% and 35 .2% of the neurons tested. The excitatory effect of ACh was dose-dependent. The effects, either excitatory or inhibitory,of ACh (n = 49) were mostly blocked by atropine (0. 3 μmol/L, n = 42). The excitatory effect of ACh (n = l4) could be blocked mainly by selective antagonist of M1 receptor,pirenzepine (PZ, 30 nmol/L, n = 9), but not by selective antagonist of M2 receptor,methoctramine (MT) and AFDX-116. The inhibitory effect of ACh (n = 10) could be blocked mostly by M2 receptor antagonist MT (30 nmol/L, n = 7); and this inhibitory effect (n = 9) could be blocked mostly by another M2 receptor antagonist AFDX-116 (30nmol/L, n = 6), but not by M1 receptor antagonist PZ.更多还原