Doctor of Philosophy (PhD)
Behavioral responses to stressors can be influenced in different ways by both serotonin (5-HT) agonists and antagonists. Further study, of both different stressors as well as different 5-HT agents, is needed to clarify the place of 5-HT in stress responding. To date, no published report has investigated the influence of centrally and/or peripherally administered 5-HT2A/C agonist DOI or the 5-HT2A/C antagonist ketanserin on behaviors evoked by tail pinch or open field stressors. Five separate, related experiments were conducted to investigate this influence. It was hypothesized that that peripherally (Experiment 1), centrally (Experiment 2), and centrally + peripherally (Experiment 3) injected DOI would reduce stress responding to tail pinch and open field stressors, and that peripheral injection of ketanserin (Experiment 4) would increase behavioral responding to stress when injected alone, as well as reverse the reduction in behavioral responding from injection of DOI (Experiment 5). The results strongly supported the hypotheses. Administration of DOI resulted in significantly decreased behavioral responding to tail pinch stress in all five experiments, regardless of route of administration. Concomitant peripheral administration of KET and DOI resulted in a reversal of the decrease in stress-evoked behaviors seen with administration of DOI alone. This is the first report of the influence of centrally and peripherally administered DOI on behaviors evoked by tail pinch or open field stress, and the reversal of that influence by the 5-HT2A/C antagonist ketanserin. Future investigations should be designed to study whether the effects observed in the current report are centrally or peripherally mediated.
Document Availability at the Time of Submission
Release the entire work immediately for access worldwide.
Uzelac, Sarah Mathews, "Serotonin and stress responding in animals: role of 5-HT.2A/C receptors in the central and peripheral nervous systems" (2005). LSU Doctoral Dissertations. 3145.