1. Stress and re-stress increases conditioned taste aversion learning in rats: Possible frontal cortical and hippocampal muscarinic receptor involvement
- Author
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Gregers Wegener, Dan J. Stein, Linda Brand, Brian H. Harvey, Ilse Groenewald, 11083417 - Harvey, Brian Herbert, and 10066357 - Brand, Linda
- Subjects
Male ,Re-stress ,Conditioned taste aversion ,Prefrontal Cortex ,Hippocampus ,Sensory system ,Muscarinic Antagonists ,Hippocampal formation ,Frontal cortex ,Rats, Sprague-Dawley ,Stress Disorders, Post-Traumatic ,Muscarinic acetylcholine receptor ,Avoidance Learning ,medicine ,Muscarinic Receptor Binding ,Animals ,Cholinergic ,Pharmacology ,Muscarinic receptor ,Receptor, Muscarinic M1 ,Posttraumatic stress disorder ,Single prolonged stress ,medicine.disease ,Receptors, Muscarinic ,Rats ,Quinuclidinyl Benzilate ,Taste ,Mental Recall ,Taste aversion ,Lithium Chloride ,Psychology ,Neuroscience ,Stress, Psychological ,Anxiety disorder - Abstract
Udgivelsesdato: 2008-May 31 Symptoms of posttraumatic stress disorder are often precipitated by sensory cues in the form of visual, auditory, olfactory and gustatory "flashbacks" resulting in enhanced fear-memory consolidation and the characteristic symptoms of re-experiencing, avoidance and hyper-arousal. Single prolonged stress with and without re-stress have been used to explore the neurobiology of this disorder, particularly with respect to contextual conditioning and spatial memory impairment. However, less work has been done regarding associative sensory-related memories linked to aversive events. Although growing evidence supports a role for cholinergic pathways in stress, this has not been studied in the above animal models. We studied the effects of single prolonged stress with and without re-stress on conditioned taste aversion learning in rats, together with differential analysis of frontal cortical and hippocampal [(3)H]-quinuclidinyl benzylate ([(3)H]-QNB) muscarinic receptor binding. Single prolonged stress with and without re-stress both enhanced associative sensory aversion learning 7 days after stressor-taste pairing, although re-stress did not strengthen this response. Increased cortical and hippocampal muscarinic receptor density (B(max)) was found 7 days after single prolonged stress with re-stress, although receptor affinity remained unaltered. Frontal cortical and hippocampal muscarinic receptor changes may thus underlie conditioned taste aversion learning in rats exposed to stress and re-stress. These data suggest that it may be useful to study the role of cholinergic pathways in mediating associative memory in psychiatric disorders such as posttraumatic stress disorder.
- Published
- 2008