Potassium currents in isolated statocyst neurons and RPeD1 in the pond snail, Lymnaea stagnalis.
Potassium currents in isolated statocyst neurons and RPeD1 in the pond snail, Lymnaea stagnalis.
复制标题
孤立的静囊神经元和池塘蜗牛 Lymnaea stagnalis 中的 RPeD1 中的钾电流。
DOI：
10.1152/jn.01163.2004
复制
发表时间：
2005
影响因子：
2.5
通讯作者：
K. Lukowiak
中科院分区：
文献类型：
--
作者：
M. Sakakibara;F. Okuda;K. Nomura;Kenji Watanabe;Hongxu Meng;T. Horikoshi;K. Lukowiak
为了开始确定记忆形成的潜在神经机制，我们研究了两种不同类型的细胞，它们在Lymneea中不同形式的联想学习中发挥了重要作用。状态囊神经元(毛细胞)介导经典的条件反射，而RPeD1是空气呼吸的操作性条件反射诱导记忆形成的场所。由于钾(K(+))通道在神经元兴奋性中起关键作用，我们在上述神经元中启动了对这些通道的研究。毛细胞胞体和RPeD1胞体均表达三种不同的K(+)电流。在毛细胞和RPeD1中，存在快速激活和快速失活的4-氨基吡啶(4-AP)敏感的A电流(I(A))、四乙基铵(TEA)敏感的延迟整流电流(I(KV))和TEA和4-AP不敏感的钙(2+)依赖电流(I(Ca-K))。在毛细胞中，I(A)的激活电压、其半最大稳态激活电压和半最大稳态失活都比RPeD1处于更去极化的水平。在毛细胞中，I(A)失活恢复的时间常数稍快一些。毛细胞的I(A)的幅度也比RPeD1的小，并且在更多的去极化电位下被激活。同样，在毛细胞中，I(KV)比RPeD1更小，并且在更多的去极化电位下被激活。
To begin to determine the underlying neural mechanisms of memory formation, we studied two different cell types that play important roles in different forms of associative learning in Lymnaea. Statocyst neurons (hair cells) mediate classical conditioning, whereas RPeD1 is a site of memory formation induced by operant conditioning of aerial respiration. Because potassium (K(+)) channels play a critical role in neuronal excitability, we initiated studies on these channels in the aforementioned neurons. Three distinct K(+) currents are expressed in the soma of both the hair cells and RPeD1. In hair cells and RPeD1, there is a fast activating and rapidly inactivating 4-aminopyridine (4-AP)-sensitive A current (I(A)), a tetraethyl ammonium (TEA)-sensitive delayed rectifying current, which exhibits slow inactivation kinetics (I(KV)), and a TEA- and 4-AP-insensitive Ca(2+)-dependent current (I(Ca-K)). In hair cells, the activation voltage of I(A); its half-maximal steady-state activation voltage and its half-maximal steady-state inactivation were at more depolarized levels than in RPeD1. The time constant of recovery from I(A) inactivation was slightly faster in hair cells. I(A) in hair cells is also smaller in amplitude than in RPeD1 and is activated at more depolarized potentials. In like manner, I(KV) is smaller in hair cells and is activated at more depolarized potentials than in RPeD1.