CCN Colloquium: "Neural population dynamics underlying the regulation of motivated behavior"
As we interact with the world around us, we experience a constant stream of sensory inputs, and generate a constant stream of behavioral actions. What makes brains more than simple input-output machines is their capacity to integrate sensory inputs with an animal's own internal motivational state-alertness, hunger, level of stress-to produce behavior in a manner that is flexible and adaptive. While some experimental work has examined the effect of motivational states such as alertness on neuronal encoding of sensory cues, a key theoretical question is how motivational states themselves are established and maintained by the brain. Here, we contrast neural population activity in two hypothalamic nuclei involved in control of social behavior, captured using microendoscopic imaging as a male mouse interacts with a male or female conspecific. We uncover region-specific dynamical regimes that encode information about animals' actions and motivational states, and uncover slow-ramping and persistent dynamics that are correlated with animals' levels of aggressive motivation. This may suggest a more general framework by which nuclei of the hypothalamus shape animal behavior via graded and persistent representations of motivational state.