Biomaterial Database

Adrenalectomy attenuates stress-induced elevations in extracellular glutamate concentrations in the hippocampus. 1993

M T Lowy, and L Gault, and B K Yamamoto

Department of Psychiatry, Case Western Reserve University, Cleveland, OH 44106.

Glucocorticoids and stress have deleterious effects on hippocampal cell morphology and survival. It has been hypothesized that these effects are mediated via an excitatory amino acid mechanism. The present study was designed to evaluate the effects of acute stress on the extracellular levels of glutamate in the hippocampus and to determine if adrenalectomy modifies this response. Rats were adrenalectomized or sham-adrenalectomized and implanted with microdialysis probes in the CA3 region of the hippocampus. Three days later rats were subjected to an acute 1-h period of immobilization stress. Stress significantly increased extracellular glutamate levels in the sham-operated rats, which peaked at 20 min following the initiation of stress. Extracellular glutamate levels also increased immediately following the termination of stress. In the adrenalectomized rats there was a 30% decrease in basal extracellular concentrations of glutamate and a marked attenuation (-70%) of the stress-induced increase in extracellular glutamate levels. Extracellular concentrations of taurine were not modified by adrenalectomy and did not change in response to stress. These results suggest that glucocorticoid-induced elevations in extracellular glutamate concentrations may contribute to the deleterious effects of stress on hippocampal neurons.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D011712	Pyramidal Tracts	Fibers that arise from cells within the cerebral cortex, pass through the medullary pyramid, and descend in the spinal cord. Many authorities say the pyramidal tracts include both the corticospinal and corticobulbar tracts.	Corticobulbar Tracts,Corticospinal Tracts,Decussation, Pyramidal,Corticobulbar Tract,Corticospinal Tract,Pyramidal Decussation,Pyramidal Tract,Tract, Corticobulbar,Tract, Corticospinal,Tract, Pyramidal,Tracts, Corticobulbar,Tracts, Corticospinal,Tracts, Pyramidal
D012149	Restraint, Physical	Use of a device for the purpose of controlling movement of all or part of the body. Splinting and casting are FRACTURE FIXATION.	Immobilization, Physical,Physical Restraint,Physical Immobilization,Physical Restraints,Restraints, Physical
D003345	Corticosterone	An adrenocortical steroid that has modest but significant activities as a mineralocorticoid and a glucocorticoid. (From Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1437)
D005110	Extracellular Space	Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.	Intercellular Space,Extracellular Spaces,Intercellular Spaces,Space, Extracellular,Space, Intercellular,Spaces, Extracellular,Spaces, Intercellular
D005971	Glutamates	Derivatives of GLUTAMIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure.	Glutamic Acid Derivatives,Glutamic Acids,Glutaminic Acids
D006624	Hippocampus	A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.	Ammon Horn,Cornu Ammonis,Hippocampal Formation,Subiculum,Ammon's Horn,Hippocampus Proper,Ammons Horn,Formation, Hippocampal,Formations, Hippocampal,Hippocampal Formations,Hippocampus Propers,Horn, Ammon,Horn, Ammon's,Proper, Hippocampus,Propers, Hippocampus,Subiculums
D000315	Adrenalectomy	Excision of one or both adrenal glands. (From Dorland, 28th ed)	Adrenalectomies
D000704	Analysis of Variance	A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.	ANOVA,Analysis, Variance,Variance Analysis,Analyses, Variance,Variance Analyses