DIFFERENTIAL FIRING PATTERN AND RESPONSE TO LIGHTING CONDITIONS OF RAT INTERGENICULATE LEAFLET NEURONS PROJECTING TO SUPRACHIASMATIC NUCLEUS OR CONTRALATERAL INTERGENICULATE LEAFLET
DIFFERENTIAL FIRING PATTERN AND RESPONSE TO LIGHTING CONDITIONS OF RAT INTERGENICULATE LEAFLET NEURONS PROJECTING TO SUPRACHIASMATIC NUCLEUS OR CONTRALATERAL INTERGENICULATE LEAFLET
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DOI：
10.1016/j.neuroscience.2012.10.044
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发表时间：
2013-01-01
期刊：
影响因子：
3.3
通讯作者：
Lewandowski, M. H.
中科院分区：
文献类型：
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作者：
Blasiak, T.;Lewandowski, M. H.
大鼠侧膝状体的膝间小叶（IGL）是一个gaba能神经元群，在解剖学和神经化学上可分为两个不同的群体。一类是神经肽y （NPY）阳性神经元，形成支配视交叉上核（SCN）的膝下丘脑束；另一类是脑啡肽阳性（ENK）神经元，形成支配对侧IGL （cIGL）的膝-膝状束。以往的电生理研究已经在体外和体内观察到IGL神经元的各种放电模式和对光照条件变化的不同反应。本研究的目的是确定这些不同的特性是否可以归因于差异投射的IGL神经元。在不同光照条件下（即明暗），记录麻醉大鼠IGL细胞外神经元活动。反向激活用于识别记录的细胞是否投射到SCN或对侧IGL。所有被识别为向对侧IGL投射的IGL神经元都表现出次慢振荡活动（ISO，即慢节奏的动作电位爆发）。这些神经元的ISO在光照下维持，在黑暗中减弱。相反，所有被确定为投射到SCN的IGL神经元在光线下表现出低水平的放电，而大多数这些细胞在黑暗中增加了放电。所有投射到SCN的IGL神经元在光照和黑暗中都表现出不规则的放电模式。这些数据首次证明了不同投射的大鼠束间小叶神经元具有不同的放电模式和对光和暗条件的相反反应。(c) 2012 ibro。Elsevier Ltd.出版。版权所有。
The intergeniculate leaflet (IGL) of the lateral geniculate body in the rat is a population of GABAergic neurons that can be divided into two, anatomically and neuro-chemically distinct populations. One population comprises neuropeptide-Y (NPY)-positive neurons that form the geniculohypothalamic tract innervating the suprachiasmatic nuclei (SCN) and the other population comprises enkephalin-positive (ENK) neurons giving rise to the geniculo-geniculate tract innervating the contralateral IGL (cIGL). Previous electrophysiological studies have observed various patterns of firing and different responses to changes in lighting conditions of IGL neurons in vitro and in vivo. The aim of the present study was to determine if these distinct properties could be ascribed to differentially projecting IGL neurons. Neuron activity was recorded extracellularly in the IGL of anaesthetised rats under different lighting conditions (i.e. light/dark). Antidromic activation was used to identify recorded cells as projecting to the SCN or the contralateral IGL. All IGL neurons identified as projecting to the contralateral IGL displayed infra-slow oscillatory activity (ISO; i.e. slow rhythmic bursts of action potentials). ISO of these neurons was sustained in the light and was diminished in the darkness. In contrast, all IGL neurons identified as projecting to the SCN displayed a low level of firing in the light and a majority of these cells increased firing in the darkness. All IGL neurons projecting to the SCN were characterised by an irregular pattern of firing in the light and dark. These data are the first to demonstrate that differentially projecting rat intergeniculate leaflet neurons are characterised by distinct firing patterns and opposite responses to light and dark conditions. (C) 2012 IBRO. Published by Elsevier Ltd. All rights reserved.