The effects of stress on ß1 thyroid hormone receptor immunoreactivity in brain

grantor: University of TorontoThe goal of this project was to determine whether stressful conditions could produce changes in ß1-like immunoreactivity in rat brain. Three stress models were used. First, social isolation was examined, but produced no changes in ß1-like immunoreactivity in the brain regions examined. Second, uncontrollable foot shock, a model of depression and a more intense form of stress, was utilized but also suggested a lack of plasticity in the ß1 receptor subtype. Third, learned helplessness was used and resulted in increased ß1-like receptor immunoreactivity in the locus coeruleus, cerebellum and superior olivary nucleus. The upregulation of the ß1 receptor subtype in the locus coeruleus is a potentially important finding, since it is a major adrenergic centre and a target for the actions of tricyclic antidepressants (TCAs) suggesting that changes in ß1 like immunoreactivity are not a result of stress per se, but may be associated with differential, depressive-type responses to stress.M.Sc