EFFECT OF UNILATERAL MOTOR CORTEX ABLATION ON ACTIVITY OF CHOLINE-ACETYLTRANSFERASE AND LEVELS OF AMINO-ACID TRANSMITTER CANDIDATES IN THE SPINAL-CORD OF ADULT MONKEYS

Citation
K. Fujita et al., EFFECT OF UNILATERAL MOTOR CORTEX ABLATION ON ACTIVITY OF CHOLINE-ACETYLTRANSFERASE AND LEVELS OF AMINO-ACID TRANSMITTER CANDIDATES IN THE SPINAL-CORD OF ADULT MONKEYS, Neurochemical research, 18(7), 1993, pp. 731-736
Citations number
22
Categorie Soggetti
Biology,Neurosciences
Journal title
ISSN journal
03643190
Volume
18
Issue
7
Year of publication
1993
Pages
731 - 736
Database
ISI
SICI code
0364-3190(1993)18:7<731:EOUMCA>2.0.ZU;2-T
Abstract
Evidence that L-glutamate is a neurotransmitter of corticofugal fibers was sought by measuring changes in several biochemical markers of neu rotransmitter function in discrete regions of spinal cord after ablati on of sensorimotor cortex in monkeys. One and five weeks after unilate ral cortical ablation, samples from six areas of spinal cord (ventral, lateral and dorsal regions of the left and right sides) were analysed for choline acetyltransferase (ChAT) activity and contents of amino a cid transmitter candidates -glutamic acid (Glu), aspartic acid (Asp), glycine (Gly), taurine (Tau) and gamma-aminobutyric acid (GABA). Durin g one to five weeks after unilateral cortical ablation of the monkey, prolonged hemiplegia in the contralateral side was observed. Histologi cal examination of the spinal cord 5 weeks after unilateral (left) cor tical ablation showed no apparent change in either control (ipsilatera l, left) or affected (contralateral, right) sides of the cord as exami ned by the Kluver-Barrera method. The ChAT activity as a cholinergic m arker was scarcely changed in any region of either left (control) or r ight (affected) side of the spinal cord at one and five weeks after un ilateral (left side) ablation of the motor cortex. Amino acid levels i n each region of the spinal cord were not significantly changed one we ek after unilateral ablation of the motor cortex. However, a significa nt decrease of Glu content was observed in the lateral column of the a ffected (right) side compared to the control (left) side of cervical a nd lumbar cord five weeks after cortical ablation of the left motor ar ea. No concomitant alterations of other amino acids were detected. The se data strongly suggest that L-Glu is a neurotransmitter for corticof ugal pyramidal tract fibers to anterior horn secondary neurons related to motor control activity in monkey spinal cord.