Meeting Abstract
The nervous system has a central role in the regulation of the cardiovascular and ventilatory systems in vertebrates. Oxygen, carbon dioxide, and arterial pressure in the blood are monitored by sensory neurons including neurons of the glossopharyngeal and vagal sensory ganglia. These sensory neurons project into the hindbrain, where signals are integrated by complex circuits that are still not fully understood. Neurons of the hindbrain then synapse onto preganglionic neurons of the parasympathetic and sympathetic nervous systems, which ultimately innervate the target organs and control heart rate, vasomotor tone, and ventilatory rate. Larval zebrafish are an ideal system in which to examine how cues are encoded by sensory neurons and integrated by hindbrain neural circuits, since their small size and optical transparency enables approaches that are difficult in other animal models. To address these questions, we recorded the responses of neurons of the vagal sensory ganglion in larval zebrafish to a range of respiratory cues including low oxygen and high carbon dioxide. Responses were quantified by expressing the fluorescent calcium indicator GCaMP6F in these neurons, imaging these neurons using in vivo multi-photon microscopy, and taking fluorescence as a measure of neural activity. We found that individual cells exhibited characteristic profiles in their response to different cues.
