Transformations and Functions of Neural Representations in a Subcortical Social Behavior Network

Citation

Yang, Bin (2022) Transformations and Functions of Neural Representations in a Subcortical Social Behavior Network. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/v13r-yt57. https://resolver.caltech.edu/CaltechTHESIS:05232022-073842501

Abstract

The brain functions by processing sensory information such as vision, smell, and touch, integrating it with internal states (hunger, fear, aggression) and memory to produce relevant motor outputs (eating, fleeing, or fighting). To understand the brain, neuroscientists study neural representations (patterns of neural activity that correlate with features of the outside world) to and perform perturbations (activate or silence groups of neurons) to determine its function. Past studies on neural representations gave us insights into how sensory regions filter complex inputs to retain relevant information and how coordinated activity in the motor regions produce complex motor actions. However, little is known about how information is processed in the inner brain (between sensory and motor) and how behaviors are controlled. Mating and aggression are innate social behaviors that are essential for animals’ survival. During social interactions, such as those preceding mating or fighting, the brain must determine the sex of a conspecific to produce sex-appropriate behaviors that are conducive to its survival. Functional studies demonstrated that they are controlled by deep subcortical circuits in the extended amygdala and hypothalamus. My thesis attempts to understand how the inner brain works by 1) showing that chemosensory cues encoding conspecific’s sex are transformed to neural representations of mating and aggression during social interactions by recording from a genetically defined group of neurons in different regions of the extended amygdala and hypothalamus. 2) Demonstrating that the neural activity representing conspecific’s sex is necessary for the emergence of behavioral representations in the hypothalamus.

Thesis Files