Excitatory and inhibitory inputs from saccular afferents to single vestibular neurons in the cat.
Excitatory and inhibitory inputs from saccular afferents to single vestibular neurons in the cat.
复制标题
从囊状传入到猫的单个前庭神经元的兴奋性和抑制性输入。
作者：
Y. Uchino;Hitoshi Sato;H. Suwa
用细胞内兴奋性（E）和抑制性（I）突触后电位（PSP）记录法研究了去大脑猫的囊状斑传入纤维与前庭神经元的联系。通过改变刺激电流极性的两种方法对囊状黄斑进行局灶性刺激。A组将电极分别插入囊状斑的腹侧和背侧边缘。局灶性刺激穿过纹状体，使得毛细胞中形态极化的逆转被脉冲刺激桥接。在22/36个前庭神经元中，刺激囊状斑可诱发单突触（≤ 1.2ms）EPSP，包括单极性刺激的EPSP-IPSP序列，改变刺激电流极性可诱发双突触（≥ 1.5ms）IPSP。在14/36个神经元中，无论刺激极性如何，反应模式都是相同的; EPSP（12/36）或IPSP（2/36）。B组在囊状斑背侧边缘插入一对电极，使电流刺激不桥接纹状体。在所有测试的前庭神经元中，无论极性如何，反应模式总是相同的：单突触（22/31）和双突触（3/31）EPSP或双突触IPSP（6/31）。另外，部分猫（C组）摘除黄斑后刺激囊神经。刺激囊神经可诱发62个前庭神经元的EPSP（包括31个神经元的EPSP-IPSP序列）和19个前庭神经元的IPSP。用细胞内PSPs记录法研究了囊神经与前庭神经的会聚。刺激椭圆囊神经、水平神经和前半规管神经后，五十六%（18/32）的囊状激活神经元产生兴奋性和/或抑制性电位，44%（19/43）的囊状激活神经元接受后半规管神经的传入。这些结果支持了这一假设，即囊状传入从一个人口的毛细胞激活前庭神经元单突触和传入从另一个人口的毛细胞位于相反侧的纹状体出现项目通过抑制性中间神经元双突触相同的前庭神经元。从囊状神经传入前庭神经元的神经回路，我们称之为跨纹状体抑制，因此可能提供了一种机制，增加垂直线性加速度的敏感性。所述电路不仅具有高灵敏度，而且具有抗输入噪声的特性。
Connections from saccular afferents to vestibular neurons were studied by means of intracellular recordings of excitatory (E) and inhibitory (I) postsynaptic potentials (PSPs) in vestibular neurons after focal stimulation of the saccular macula in decerebrated cats. Focal stimulation was given to the saccular macula in two ways, in which the polarity of stimulus current via a pair of electrodes was changed. In group A, one of the electrodes was inserted into the ventral and the other into the dorsal edge of the saccular macula. The focal stimulation was across the striola so that the reversal of morphological polarization in hair cells was bridged by the pulse stimulus. In 22/36 vestibular neurons tested, the stimulation of the saccular macula evoked monosynaptic (</=1.2 ms) EPSPs, including EPSP-IPSP sequences, with one polarity of stimulation, and disynaptic (>/=1.5 ms) IPSPs when the polarity of the stimulus current was changed. In 14/36 neurons, the response pattern was the same regardless of the stimulus polarity; EPSPs (12/36) or IPSPs (2/36). In group B, a pair of electrodes was inserted into the dorsal edge of the saccular macula, so that the striola was not bridged by the current stimulus. In all of the vestibular neurons tested, the response pattern was always the same regardless of the polarity: mono- (22/31) and disynaptic (3/31) EPSPs or disynaptic IPSPs (6/31). In addition, the saccular nerve was stimulated after removing the macula in some cats (group C). The stimulation of the saccular nerve evoked EPSPs in 62 vestibular neurons (including EPSP-IPSP sequences in 31 neurons) and IPSPs in 19 vestibular neurons. Convergence between the saccular nerve and other vestibular nerves was studied by the intracellular recording of PSPs. Fifty-six percent (18/32) of the saccular-activated neurons had excitatory and/or inhibitory potentials evoked after stimulation of the utricular nerve and the horizontal and anterior semicircular canal nerves, and 44% (19/43) of the neurons received inputs from the posterior semicircular canal nerve. The results support the hypothesis that saccular afferents from one population of hair cells activate vestibular neurons monosynaptically and that afferents from another population of hair cells located on the opposite side of the striola appear to project to the same vestibular neurons disynaptically via inhibitory interneurons. Neural circuits from saccular afferents to vestibular neurons, which we term cross-striolar inhibition, thus may provide a mechanism for increasing the sensitivity to vertical linear acceleration. The circuit described is provided not only with high sensitivity but also with input noise-resistant characteristics.
影响因子：
2.5
作者：
FERNANDEZ, C;BAIRD, RA;GOLDBERG, JM
通讯作者：
GOLDBERG, JM
影响因子：
2.5
作者：
BAIRD, RA;DESMADRYL, G;GOLDBERG, JM
通讯作者：
GOLDBERG, JM
影响因子：
2.5
作者：
GOLDBERG, JM;DESMADRYL, G;FERNANDEZ, C
通讯作者：
FERNANDEZ, C