当前位置： SCI文献检索 > BRAIN RESEARCH期刊下所有文献 > Response of medial medullary reticular neurons to otolith stimulation during bidirectional off-vertical axis rotation of the cat.

Response of medial medullary reticular neurons to otolith stimulation during bidirectional off-vertical axis rotation of the cat.

Abstract：

:In decerebrate cats, the extracellular activities of neurons in the medial medullary reticular formation were studied during constant velocity off-vertical axis rotations (OVAR) in the clockwise (CW) and counterclockwise (CCW) directions (at 10 degrees tilt). Spontaneously active neurons demonstrated sinusoidal position-dependent discharge modulations to OVAR which selectively stimulates the otoliths. Two features of neuronal responses to bidirectional OVAR were identified. Within the velocity spectrum tested (1.75-15 degrees/s), some neurons showed symmetric bidirectional response sensitivity (delta value) to CW and CCW rotations. The spread of the delta values of each of these neurons with velocity was small. This group of reticular neurons were described as exhibiting symmetric and velocity-stable bidirectional response sensitivity. The mathematically derived gain tuning ratios of these neurons were within the range of narrowly spatiotemporal-tuned neurons. Another group of reticular neurons, however, showed asymmetric bidirectional response sensitivity to CW and CCW rotations; a few of these neurons were responsive only to OVAR of one direction but not to both. For each of this second group of neurons, the spread of the delta values with velocity was large. These reticular neurons were described as exhibiting asymmetric and velocity-variable bidirectional response sensitivity. The gain tuning ratios of these latter neurons were found to be within the range of broadly spatiotemporal-tuned neurons. Single neurons of both groups displayed orientational tuning. Both the best response orientations of neurons that showed symmetric and velocity-stable bidirectional response sensitivity and the preferred orientations of neurons that showed asymmetric and velocity-variable bidirectional response sensitivity were found to point in all directions on the rotary plane. The response dynamics of the former group of neurons was also examined. All showed flat response gain across the entire velocity range. Some showed a flat response lead while others showed a progressive shift from small response lead at low velocity to phase close to zero at higher velocities. The functional significance of these medial medullary reticular neurons to the direction and orientation of head tilt is discussed.

journal_name

Brain Res

journal_title

Brain research

authors

Chan YS,Chen CW,Lai CH

doi

10.1016/0006-8993(96)00516-1

subject

Has Abstract

pub_date

1996-09-02 00:00:00

pages

159-68

issue

1-2

eissn

0006-8993

issn

1872-6240

pii

0006-8993(96)00516-1

journal_volume

732

pub_type

杂志文章

在线工具

Response of medial medullary reticular neurons to otolith stimulation during bidirectional off-vertical axis rotation of the cat.