Intrinsic firing patterns and whisker-evoked synaptic responses of neurons in the rat barrel cortex.
Intrinsic firing patterns and whisker-evoked synaptic responses of neurons in the rat barrel cortex.
复制标题
DOI：
10.1152/jn.1999.81.3.1171
复制
发表时间：
1999-03
影响因子：
2.5
通讯作者：
J. Julius Zhu;Barry W. Connors
中科院分区：
文献类型：
--
作者：
J. Julius Zhu;Barry W. Connors
我们在麻醉大鼠上用全细胞记录法研究了桶状皮层单个神经元的须诱发突触和棘波反应。根据神经元的内在放电模式，神经元可分为规则发放（RS）细胞、内在爆发发放（IB）细胞和快速发放（FS）细胞。一些录音响应电流注入一个复杂的尖峰模式的特点顶端树突。所有细胞类型的自发突触后电位，兴奋性（EPSP）和抑制性（IPSP）的高利率。一些自发性EPSP达到阈值，并且这些通常仅在RS细胞中引起单个动作电位，在FS细胞和IB细胞中引起动作电位爆发，以及在树突中引起小的快速尖峰或复杂尖峰。单个触须的偏转在所有类型的细胞中诱发了快速的初始EPSP、延长的IPSP和延迟的EPSP。细胞的内在放电模式预测其短潜伏期胡须诱发的尖峰模式。所有细胞类型对一个或偶尔两个初级须的反应最好，但通常6-15个周围的须也产生显著的突触反应。初始EPSP具有相对固定的振幅和潜伏期，其对一阶周围触须的反应振幅约为初级触须的55%。二阶和三阶周围的胡须引起的反应分别约为27%和12%。起始EPSP的潜伏期以初级须最短，周围须较长，且随软膜以下神经元的深度而变化。EPSP潜伏期在颗粒层最短，在颗粒上层较长，在颗粒下层最长。感受野的大小，定义为总数量的快速EPSP诱导晶须，是独立的每个细胞的内在的放电类型，其软膜下的深度，或晶须刺激参数。平均而言，感受野包括>10根胡须。我们的研究结果表明，单个神经元集成快速突触反应的大比例的mystyrus触须，并建议，桶神经元的胡须诱发的反应是一个函数的突触输入和内在的膜特性。
We have used whole cell recording in the anesthetized rat to study whisker-evoked synaptic and spiking responses of single neurons in the barrel cortex. On the basis of their intrinsic firing patterns, neurons could be classified as either regular-spiking (RS) cells, intrinsically burst-spiking (IB) cells, or fast-spiking (FS) cells. Some recordings responded to current injection with a complex spike pattern characteristic of apical dendrites. All cell types had high rates of spontaneous postsynaptic potentials, both excitatory (EPSPs) and inhibitory (IPSPs). Some spontaneous EPSPs reached threshold, and these typically elicited only single action potentials in RS cells, bursts of action potentials in FS cells and IB cells, and a small, fast spike or a complex spike in dendrites. Deflection of single whiskers evoked a fast initial EPSP, a prolonged IPSP, and delayed EPSPs in all cell types. The intrinsic firing pattern of cells predicted their short-latency whisker-evoked spiking patterns. All cell types responded best to one or, occasionally, two primary whiskers, but typically 6-15 surrounding whiskers also generated significant synaptic responses. The initial EPSP had a relatively fixed amplitude and latency, and its amplitude in response to first-order surrounding whiskers was approximately 55% of that induced by the primary whisker. Second- and third-order surrounding whiskers evoked responses of approximately 27 and 12%, respectively. The latency of the initial EPSP was shortest for the primary whiskers, longer for surrounding whiskers, and varied with the neurons' depth below the pia. EPSP latency was shortest in the granular layer, longer in supragranular layers, and longest in infragranular layers. The receptive field size, defined as the total number of fast EPSP-inducing whiskers, was independent of each cell's intrinsic firing type, its subpial depth, or the whisker stimulus parameters. On average, receptive fields included >10 whiskers. Our results show that single neurons integrate rapid synaptic responses from a large proportion of the mystacial vibrissae, and suggest that the whisker-evoked responses of barrel neurons are a function of both synaptic inputs and intrinsic membrane properties.