Effects of spinal transection on presynaptic markers for glutamatergic neurons in the rat

Journal Article · Fri May 01 04:00:00 EDT 1981 · Neurochem. Res.; (United States)

DOI:https://doi.org/10.1007/BF00964388· OSTI ID:5402660

Singer, H S; Coyle, J T; Frangia, J; Price, D L

To evaluate the hypothesis that glutamic acid may be the neurotransmitter of descending, excitatory supraspinal pathways, the uptake and release of L-(3H) glutamate and the levels of endogenous glutamate were measured in preparations from rat lumbar spinal cord following complete mid-thoracic transection. Following transection, the activity of the synaptosomal high-affinity glutamate uptake process was increased in both dorsal and ventral halves of lumbar cord between 1 and 14 days after transection and returned to control levels by 21 days posttransection. At 7 days, the increased activity of the uptake process for L-(3H)glutamate resulted in elevation of Vmax with no significant alteration in KT as compared to age-matched controls. Depolarization-induced release of L-(3H)glutamate from prelabeled slices did not differ significantly from control in the lesioned rat except at 21 days after lesion when the amount of tritium release was significantly greater in the transected preparations than in control. Amino acid analysis of the lumbar cord from control and transected rats indicated only a 10% decrease in the level of endogenous glutamate and no alterations in the concentration of GABA and glycine 7 days after lesion. These findings do not support the hypothesis that glutamate serves as a major excitatory neurotransmitter in supraspinal pathways innervating the lumbar cord of the rat.

• OSTI ID: 5402660
• Journal Information: Neurochem. Res.; (United States), Journal Name: Neurochem. Res.; (United States) Vol. 6:5; ISSN NERED
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMAL CELLS
ANIMALS
BIOLOGICAL FUNCTIONS
BIOLOGICAL PATHWAYS
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM
FUNCTIONS
GLUTAMIC ACID
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MEDICINE
NERVE CELLS
NERVOUS SYSTEM
NEUROLOGY
ORGANIC ACIDS
ORGANIC COMPOUNDS
PHYSIOLOGY
RATS
RECEPTORS
RODENTS
SOMATIC CELLS
SPINAL CORD
TRITIUM COMPOUNDS
VERTEBRATES