Electrophysiological and morphological properties of identified crossed tecto-reticular neurons in the rat superior colliculus
Electrophysiological and morphological properties of identified crossed tecto-reticular neurons in the rat superior colliculus
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DOI：
10.1016/j.neures.2005.03.007
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发表时间：
2005-06-01
影响因子：
2.9
通讯作者：
Isa, T
中科院分区：
文献类型：
--
作者：
Sooksawate, T;Saito, Y;Isa, T
在此之前，我们将随机取样的大鼠上丘中间层（SI）神经元根据其对去极化电流脉冲的放电反应分为6个亚类，根据其在切片制备中的形态特征分为5个亚类。在本研究中，我们研究了大鼠SC （PND 17-24）的主要输出细胞群，交叉构造网状神经元（ctrn）的特性，这些神经元投射到对侧内侧桥脑网状结构。用荧光示踪剂逆行标记识别ctrn （n = 112）。我们将它们的特性与假定的中间神经元的特性进行了比较（n = 127）。我们发现大多数ctrn是正常的尖峰神经元，放电频率适中（73%），多极形状（66%）。与假定的中间神经元相比，ctrn具有更大的膜电容、更大的胞体尺寸和更低的输入阻抗。电刺激浅灰质层诱导ctrn的epsp寡突触。当细胞外溶液中加入二胡兰时，epsp明显增强，并诱导爆发尖峰反应。应用d -2-氨基-5-磷酸戊酸抑制了破裂反应。这些结果表明ctrn对视觉输入表现出NMDA受体依赖的爆发反应。这些观察结果让我们深入了解ctrn中产生突发活动的神经元机制，从而触发定向行为。(c) 2005爱思唯尔爱尔兰有限公司和日本神经科学学会。版权所有。
Previously we classified randomly sampled neurons in the intermediate layer (SI) of the rat superior colliculus (SC) into six subclasses according to their firing responses to depolarizing current pulses and five subclasses based on their morphological properties in slice preparations. In the present study, we investigated properties of a major output cell group of the rat SC (PND 17-24), crossed tecto-reticular neurons (cTRNs), which project to the contralateral medial pontine reticular formation. The cTRNs were identified by retrograde labeling with a fluorescent tracer (n = 112). We compared their properties with those of presumed interneurons (n = 127). We found that a majority of cTRNs were regular spiking neurons with moderate firing frequency (73%) and were multipolar-shaped (66%). The cTRNs had larger membrane capacitance, larger soma size and lower input impedance than presumed interneurons. Electrical stimulation of the superficial gray layer induced oligosynaptic EPSPs in the cTRNs. When bicuculline was added to the extracellular solution, the EPSPs were markedly enhanced and bursting spike responses were induced. The bursting responses were suppressed by applying D-2-amino-5-phosphonovalerate. These results suggest that the cTRNs exhibit NMDA receptor-dependent bursting responses to visual inputs. These observations give insights into the neuronal mechanism of generating burst activity in cTRNs, which triggers orienting behaviors. (c) 2005 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.