Meeting Abstract
An animal’s ability to perform context-specific behaviors in response to immediate threats is an essential skill for survival and reproduction, yet little is understood about the non-genomic mechanisms involved in acute contexts. In rough-skinned newts (Taricha granulosa), the stress hormone corticosterone suppresses clasping, a context-specific sex behavior, via cannabinoid (CB) signaling. Prior research suggests that endocytosis of vasotocin, the analogue to mammalian vasopressin, is required for clasping and is blocked by elevated corticosterone. This research project aims to identify if, and to what extent, transient receptor potential vanilloid 1 (TRPV1) is involved in CB-mediated suppression of vasotocin. N-arachidonoyl-dopamine (NADA) is an endogenous agonist of TRPV1 and CB1 receptors, which are both expressed in the medullary reticular formation of Taricha. Given its dual role as an endocannabinoid and endovaniloid, it is predicted that NADA (2.2ng/μl) administered via intracerebroventricular injection will, like other endocannabinoids, suppress vasotocin endocytosis. We examine whether pre-treatment with the TRPV1 antagonist SB366791 (0.29ng/μl) and/or the CB1 antagonist AM281 (50ng/μl) will inhibit NADA (2.2ng/μl) suppression of vasotocin endocytosis, and if so to what extent. We have used quantitative confocal imaging to examine this question, focusing on the rostromedial reticular formation in the medulla oblongata as it is a primary mediator of behavioral switching and initiation of locomotion in all tetrapods.
