Hammack Sayamwong E, Mania Irakli, Rainnie Donald G
Department of Psychiatry and Behavioral Science, Center for Behavioral Neuroscience, Emory University, Atlanta, Georgia 30329, USA.
J Neurophysiol. 2007 Aug;98(2):638-56. doi: 10.1152/jn.00382.2007. Epub 2007 May 30.
The anterolateral group of the bed nucleus of the stria terminalis (BNST(ALG)) plays a critical role in a diverse array of behaviors, although little is known of the physiological properties of neurons in this region. Using whole cell patch-clamp recordings from rat BNST(ALG) slices in vitro, we describe three distinct physiological cell types. Type I neurons were characterized by the presence of a depolarizing sag in response to hyperpolarizing current injection that resembled activation of the hyperpolarization-activated cation current I(h) and a regular firing pattern in response to depolarizing current injection. Type II neurons exhibited the same depolarizing sag in response to hyperpolarizing current injection, but burst-fired in response to depolarizing current injection, which was indicative of the activation of the low-threshold calcium current I(T). Type III neurons did not exhibit a depolarizing sag in response to hyperpolarizing current injection, but instead exhibited a fast time-independent rectification that became more pronounced with increased amplitude of hyperpolarizing current injection, and was indicative of activation of the inwardly rectifying potassium current I(K(IR)). Type III neurons also exhibited a regular firing pattern in response to depolarizing current. Using voltage-clamp analysis we further characterized the primary active currents that shaped the physiological properties of these distinct cell types, including I(h), I(T), I(K(IR)), the voltage-dependent potassium current I(A), and the persistent sodium current I(NaP). The functional relevance of each cell type is discussed in relation to prior anatomical studies, as well as how these currents may interact to modulate neuronal activity within the BNST(ALG).
终纹床核前外侧组（BNST(ALG)）在多种行为中起着关键作用，尽管对该区域神经元的生理特性了解甚少。利用体外大鼠BNST(ALG)脑片的全细胞膜片钳记录，我们描述了三种不同的生理细胞类型。I型神经元的特征是，在注入超极化电流时出现去极化凹陷，类似于超极化激活阳离子电流I(h)的激活，并且在注入去极化电流时呈现规则的放电模式。II型神经元在注入超极化电流时也表现出相同的去极化凹陷，但在注入去极化电流时出现簇状放电，这表明低阈值钙电流I(T)被激活。III型神经元在注入超极化电流时未表现出去极化凹陷，而是表现出一种与时间无关的快速整流，随着超极化电流注入幅度的增加，这种整流变得更加明显，这表明内向整流钾电流I(K(IR))被激活。III型神经元在注入去极化电流时也呈现规则的放电模式。利用电压钳分析，我们进一步表征了塑造这些不同细胞类型生理特性的主要活动电流，包括I(h)、I(T)、I(K(IR))、电压依赖性钾电流I(A)和持续性钠电流I(NaP)。结合先前的解剖学研究，讨论了每种细胞类型的功能相关性，以及这些电流如何相互作用以调节BNST(ALG)内的神经元活动。
