Stress, Chemical Defense Agents and Cholinergic Receptors
Abstract
The goal of this project is to assess the effects of exposure to a chemical defense agent (XGD; soman) on anxiety and stress, by using rat models of anxiety (conditioned emotional response, CER) and unconditioned non-specific stress. To test for changes in anxiety, extinction from CER was measured, based on the hypothesis that increased anxiety produced by environmental exposures would prolong extinction. The specific experiments determined the plasticity of muscarinic cholinergic binding-sites in the central nervous system. The effects of acute exposure to doses of soman on lethality and well-characterized behaviors were examined, and found to be consistent with previous reports. The binding of radiolabelled cholinergic (ACh) ligands to brain tissue was studied in vitro. The major findings are that CER produces increases in acetycholine turnover in brain areas involved in anxiety, and that primarily post-synaptic M1 ACh receptors decrease. These neurochemical phenomena are directly correlated with several behaviors, including acquisition and extinction of CER and non- specific stress. If soman exposure increased anxiety under any conditions, this should be reflected in increased time of CER extinction and changes in receptors; the behavioral response was not observed, so receptor function was not assessed. Therefore, the effect of soman exposure on anxiety is not likely to be specific to the cholinergic system. Anxiety, Acetylcholine, CD Agents, Acetylcholinesterase, Inhibitors, Brain receptors, RA1.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 31, 1991
- Accession Number
- ADA256166
Entities
People
- John D. Lane
Organizations
- University of North Texas Health Science Center