Rapid changes in monoamine levels following administration of corticotropin-releasing factor or corticosterone are localized in the dorsomedial hypothalamus.
Monoaminergic systems are important modulators of the neuroendocrine, autonomic, and behavioral responses to stress-related stimuli. The male roughskin newt (Taricha granulosa) was used as a model system to investigate the effects of corticotropin-releasing factor (CRF) or corticosterone administration on tissue concentrations of norepinephrine, epinephrine, dopamine, 3,4-dihydroxyphenylacetic acid, serotonin, and 5-hydroxyindoleacetic acid (5-HIAA) in microdissected brain areas. Intracerebroventricular infusion of 25 or 50 ng of CRF increased locomotor activity and site-specifically increased dopamine concentrations within the dorsomedial hypothalamus 30 min after treatment when compared to vehicle-treated controls. In further studies, male newts were treated as follows: (1) no injection, no handling, (2) saline injection, or (3) 10 microg corticosterone and then placed in a novel environment. Monoamine and monoamine metabolite concentrations were similar in the unhandled and saline-injected controls 20 min after treatment. In contrast, corticosterone-injected newts had elevated concentrations of dopamine, serotonin, and 5-HIAA in the dorsomedial hypothalamus (a region that contains dopamine- and serotonin-accumulating neuronal cell bodies in representatives of all vertebrate classes) but not in several other regions studied. These site-specific neurochemical effects parallel neurochemical changes observed in the dorsomedial hypothalamic nucleus of mammals following exposure to a variety of physical and psychological stress-related stimuli. Therefore, these changes may reflect highly conserved, site-specific neurochemical responses to stress and stress-related neurochemicals in vertebrates. Given the important role of the dorsomedial hypothalamus in neuroendocrine, autonomic, and behavioral responses to stress, and a proposed role for this region in fast-feedback effects of glucocorticoids on the hypothalamo-pituitary-adrenal axis, these stress-related monoaminergic changes are likely to have important physiological or behavioral consequences.
Lowry
C A
CA
University Research Centre for Neuroendocrinology, University of Bristol, Marlborough Street, Bristol BS2 8HW, United Kingdom.
Burke
K A
KA
Renner
K J
KJ
Moore
F L
FL
Orchinik
M
M
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001007:Anxiety / Q000378:metabolism; D003345:Corticosterone / Q000494:pharmacology*; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D004302:Dorsomedial Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism*; D008124:Locomotion / Q000502:physiology; D008297:Male; D012455:Salamandridae; D012701:Serotonin / Q000378:metabolism*; D012726:Sexual Behavior, Animal / Q000502:physiology; D013315:Stress, Psychological
D000893:Anti-Inflammatory Agents; D012701:Serotonin; D003346:Corticotropin-Releasing Hormone; D004298:Dopamine; D003345:Corticosterone