DEVELOPMENT OF INTRINSIC ELECTROPHYSIOLOGICAL PROPERTIES IN NEURONS FROM THE GUSTATORY REGION OF RAT NUCLEUS OF SOLITARY TRACT
DEVELOPMENT OF INTRINSIC ELECTROPHYSIOLOGICAL PROPERTIES IN NEURONS FROM THE GUSTATORY REGION OF RAT NUCLEUS OF SOLITARY TRACT
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DOI：
10.1016/0165-3806(95)00020-e
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发表时间：
1995-05-26
期刊：
影响因子：
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通讯作者：
MISTRETTA, CM
中科院分区：
文献类型：
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作者：
BAO, H;BRADLEY, RM;MISTRETTA, CM
有没有目前的理解的性质或时间过程中成熟的内在电生理特性的孤束核（NST）的味觉区的神经元。因此，我们使用全细胞记录在体外切片制备的大鼠脑干的特点发展的静息膜，动作电位和重复放电特性的味觉NST细胞在出生后第5，10，15，20和30天，和成人年龄。用生物胞素填充神经元以验证位置并表征形态。来自年轻神经元的膜表现出比成熟细胞更陡峭的电流-电压关系或更高的输入电阻，以及更长的时间常数。年轻细胞的动作电位上升速度较慢，持续时间较长。后超极化，通常遵循的尖峰放电通常有一个阶段，在年轻的神经元，但其特点是两个或两个以上的阶段，在越来越多的老年细胞的比例。重复放电频率响应于一系列的去极化电流脉冲在发展过程中增加，和频率/电流图是陡峭的老年人相比，年轻的神经元。然而，在所有年龄组有明确的住宿的放电频率。静息膜、动作电位和放电特性的最大变化在P5和P15之间观察到，并且通常在P20达到成熟值。在每个出生后的年龄，神经元可以分为四个神经元组，根据放电模式，以响应超极化/去极化电流协议。解剖重建表明，虽然细胞在发育过程中增加了整体树突扩张，神经元变得不那么复杂，如树突分支点的数量减少，以及棘的数量和密度。在这里观察到的内在电特性的主要发展差异的时间与以前报道的成熟的细胞外味觉反应的化学刺激的数量和浓度的变化。然而，细胞外味觉反应的进一步改变在内在神经特性明显成熟后进行。
There is no current understanding of the nature or time course of maturation of intrinsic electrophysiological properties for neurons in the gustatory region of the nucleus of the solitary tract (NST). Therefore, we used whole cell recordings in an in vitro slice preparation of the rat brainstem to characterize development of resting membrane, action potential and repetitive discharge properties of cells in gustatory NST at postnatal days 5, 10, 15, 20, and 30, and adult ages. Neurons were filled with Biocytin to verify location and characterize morphology. Membranes from younger neurons demonstrated a steeper current-voltage relation or higher input resistance, and a longer time constant than mature cells. Action potentials in younger cells had a slower rate of rise and were longer in duration. The afterhyperpolarization that typically follows the spike discharge usually had one phase in younger neurons, but was characterized by two or more phases in an increasing proportion of older cells. The repetitive discharge frequency in response to a range of depolarizing current pulses increased during development, and frequency/current plots were steeper in older compared with younger neurons. However, in all age groups there was clear accommodation of the discharge frequency. The greatest changes in resting membrane, action potential, and discharge properties were observed between P5 and P15, and mature values were generally reached by P20. At each postnatal age, neurons could be categorized in four neuron groups, based on the discharge pattern in response to a hyperpolarizing/depolarizing current protocol. Anatomical reconstructions indicated that although cells increased in overall dendritic expanse during development, neurons became less complex as illustrated by decreases in number of dendritic branch points, and in number and density of spines. The timing of major developmental differences in intrinsic electrical characteristics observed here is associated with a period of previously reported maturational changes in extracellular taste responses to number and concentration of chemical stimuli. However, further alterations in extracellular taste responses proceed after apparent maturation of intrinsic neural properties.