The role of intrinsic and agonist-activated conductances in determining the firing patterns of preoptic area neurons in the guinea pig.
The role of intrinsic and agonist-activated conductances in determining the firing patterns of preoptic area neurons in the guinea pig.
复制标题
内在电导和激动剂激活电导在确定豚鼠视前区神经元放电模式中的作用。
DOI：
10.1016/s0006-8993(00)02698-6
复制
发表时间：
2000
期刊：
影响因子：
2.9
通讯作者：
Kelly,MJ
中科院分区：
文献类型：
--
作者：
Wagner,EJ;Reyes-Vazquez,C;Ronnekleiv,OK;Kelly,MJ
Whole-cell and intracellular recordings were made in coronal hypothalamic slices prepared from ovariectomized female guinea pigs. 62% of preoptic area (POA) neurons fired action potentials in a bursting manner, and exhibited a significantly greater afterhyperpolarization (AHP) than did non-bursting POA neurons. The majority (70%) of POA neurons (n=76) displayed a time-dependent inward rectification (Ih) that was blocked by CsCl (3 mM) or by ZD 7288 (30 μM). In addition, 51% of the cells expressed a low-threshold spike (LTS) associated with a transient inward current (IT) that was blocked by NiCl2(200 μM). A smaller percentage of POA neurons (29%) expressed a transient outward, A-type K+current that was antagonized by a high concentration of 4-aminopyridine (3 mM). Moreover, POA neurons responded to bath application of the μ-opioid receptor agonist DAMGO (93%) or the GABABreceptor agonist baclofen (83%) with a membrane hyperpolarization or an outward current. These responses were accompanied by a decrease in input resistance or an increase in conductance, respectively, and were attenuated by BaCl2(100 μM). In addition, the reversal potential for these responses closely approximated the Nernst equilibrium potential for K+. These results suggest that POA neurons endogenously express to varying degrees an AHP, an Ih, an ITand an A-type K+current. The vast majority of these neurons also are inhibited upon μ-opioid or GABABreceptor stimulation via the activation of an inwardly-rectifying K+conductance. Such intrinsic and transmitter-activated conductances likely serve as important determinants of the firing patterns of POA neurons.
