Neural mechanisms of social preferences

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Vocal communication is an integral component of social behavior across a wide range of species. For communication systems to function, receivers must properly perceive and respond to communication signals. Perception of and preference for particular vocal signals has been a focus of studies on female mate choice. However, perception is not static, but instead can be shaped and modulated by both developmental and adult experiences. In particular, recent studies in the mammalian auditory system have highlighted how developmental and adult acoustic experience can influence the neural responses and receptive fields of individual neurons in the auditory cortex. The neurotransmitter dopamine has been hypothesized to be significant to these plastic changes in neural response. For example, social and sensory experience appear to modulate levels of the neurotransmitter dopamine within the auditory cortex, and the stimulation of dopaminergic neurons leads to changes in the plasticity and encoding of behaviorally-relevant, salient stimuli. The long-term aim of my research is to integrate these two research directions, in particular, to investigate the plasticity and neuromodulation of neural responses to signals important for mate choice and preference. We study this in a female songbird, the zebra finch, where female preferences for song have been well-documented and neural substrates are tractable for monitoring and manipulation. Using a combination of neurophysiological, pharmacological, and immunohistochemical methods, I will investigate the neural mechanisms underlying perception and preferences and how they are shaped by social and sensory experiences in songbirds. In particular, we will investigate the degree to which dopamine and developmental experience mediate variation in the processing of socially relevant stimuli through two broad aims. For Aim 1, we will investigate the degree to which dopamine modulates neural responses to acoustic stimuli that vary in attractiveness. In addition, we will determine the degree to which natural interactions, in particular mating, modulate dopamine neuron activity and preference. In Aim 2, we will examine the developmental trajectory of auditory and dopamine neuron responses to socially modulated song and investigate how hearing song for the first time reorganizes auditory responses in females raised without developmental song exposure. We will also perform circuit-breaking studies to test the contributions of auditory and dopamine inputs to developmental song preference learning. Together, the studies proposed here will provide us with novel insights into how experiences throughout the lifespan can modulate preference and perception as well as their neural substrates.