Meeting Abstract
The stress response of vertebrates can be initiated by many different environmental stimuli including extreme temperatures, noxious chemicals, mechanical disturbance, visual stimuli and pain. These sensory inputs are integrated within the central nervous system (CNS), which then drives responses in the peripheral nervous and endocrine systems. Catecholamines and cortisol are released into the blood, resulting in a cascade of physiological changes that includes shifts in heart rate, blood pressure, and plasma glucose levels. Although the physiological effects of stress have been well-studied, the mechanisms by which stress modulates CNS activity and alters behavioral responses are not well understood. Zebrafish larvae are an ideal organism in which to examine this question, since they are very well-suited to most behavioral and neurobiological methods. Larval zebrafish exhibit a weak preference for well-lit areas, and previous studies have suggested that stress modulates this behavior by enhancing light preference. We conducted a broad survey of this behavior in order to identify the features of the visual stimulus that affect this behavior, the specific kinematic changes that produce the observed light preference, and the effects of specific stressors (electric shock, noxious chemicals) on responses. Our results suggest that stressors produce characteristic changes in light preference and exploratory behavior. We then used multiphoton in vivo calcium imaging to identify neuronal populations in the hindbrain associated with stressful stimuli, and small-molecule blockade to identify neuron types necessary for stress-induced changes in behavior. Our results suggest a simple pathway for stress-induced modulation of exploratory pathway.
