[Use of Transsynaptic Viral Tracers for Observing Neural Circuit Control of Physiological Responses].

Central neural circuits in the brain receive and integrate environmental and internal information to enable the animals to execute appropriate behaviors and physiological responses. Communication between the brain and peripheral organs via peripheral neural circuits maintains energy homeostasis in the body. Therefore it is important to investigate the anatomical organization of central and peripheral neural circuits for elucidating the mechanisms of energy homeostasis. Transsynaptic viral tracers can travel through connected neurons via synaptic connections and have been used to delineate the anatomical organization of neural circuits with specific functions. Herein, I review our recent studies investigating neural circuits and their involvement in physiological changes using transsynaptic tracers.