Meeting Abstract
Navigation of feed vs. flee trade-offs is crucial for survival and fitness. To do this animals must integrate sensory and somatic information. The optic tectum (OT) integrates visual and lateral line information and sends projections to the brain stem and spinal cord, thus it may link sensory cues with motor output. The precise cues and neuromodulators of this trade-off are not entirely known, but neuropeptides associated with the physiological stress response may play a role. CRF, well known for its role in the hypothalamic-pituitary-interrenal axis, is abundant in the OT. In the South African clawed frog (Xenopus laevis) stressor or predator exposure decreases feeding and increases OT CRF, and elevated OT CRF decreases feeding; blocking CRFR1 reverses outcomes. The CRFR1 may be acting on visual, lateral line, and/or multiple sensory modalities. In the visual system, CRF may alter the way food items are perceived. Here, we test the prediction that OT CRF injection will decrease the response to visual stimuli. We initially tested multiple releasing stimuli previously used in adult frogs before finding a purely visual stimulus (iPad) that repeatedly elicited behavioral responses in juveniles. Frogs were injected with one of 4 doses of CRF, saline, or left unmanipulated; 1 h later they were exposed to visual prey cues (iPad movie) and then to a live worm (positive control). After 72 h, behavioral tests were repeated. All trials were video recorded. Analysis of discrete behaviors is underway. Preliminary analyses suggest CRF decreases the response to visual stimuli, and to live prey, but does not completely abolish responses. Our data will aid in understanding the neuroendocrine mechanisms governing feed/flee trade-offs. Funded by the NSF (Grant No. 1656734).
