CODDINGTON, EJ; ROSE, JD; MOORE, FL; Univ. Wyoming, Laramie; Univ. Wyoming, Laramie; Oregon State Univ., Corvallis: Endogenous Cannabinoid Signaling System Regulates Neuroendocrine Control of Behavior in an Amphibian, Taricha granulosa.

Prior research has established endocannabinoid signaling as an important basic neural process, but, the physiological mechanism by which endocannabinoids regulate vertebrate behavior remains unknown. Truncated preparations revealed endocannabinoid cellular signaling mechanisms but a whole, behaving organism needs to be studies to reveal integrated, systems level endocannabinoid functions in behavior. Studies of rough skin newts, Taricha granulosa, have revealed neuroendocrine and neurophysiological controls of behavior. These studies provide a well understood model through which we have discovered that endocannabinoids are involved in the control of male Taricha behavioral responses to acute stress. Collectively, the present and previous research in this species shows that the neuroendocrine pathway controlling stress-induced suppression of reproductive behaviors involves the following steps: an increase in plasma CORT increases endocannabinoid activity at CB1 receptors, and subsequent suppression of medullary neuron responses to clasp-triggering somatosensory information. Given that endocrine responses to acute stress and cannabinoid receptors are conserved across vertebrate taxa, endocannabinoids may also regulate the behavioral effects of acute stress, especially suppressed reproductive behaviors in fishes, reptiles, other tetrapods, and birds. Our findings suggest that endocannabinoid signaling is an integral component of other neuroendocrine signaling processes.