Neuromodulation of experience-dependent sexually dimorphic learning
How do sex-specific evolutionary drives influence decision-making processes when facing a shared environmental cue? Given the sex biases in disease states, some of which include a significant cognitive component, it is crucial to evaluate the influence of genetic sex on brain mechanisms from the ground up. In my thesis, I investigate if and how the genetic sex affects context and experience-dependent behavioral plasticity when learning an environmental cue. By utilizing a genes-to-behavior approach, I unravel sexual dimorphism in an ethologically relevant behavioral paradigm. C. elegans males do not learn to avoid the pathogenic bacteria PA14 as efficiently and rapidly as hermaphrodites, even though the pathogenicity is perceived. I explore the neuronal representations following training that encode this dimorphism and observe a possible sensory gating mechanism. The transcriptomic and subsequent behavioral analysis revealed the influence of the neuromodulatory network on male behavior. In particular, npr-5, an ortholog of the mammalian NPY receptor, regulates male learning by modulating typical neuronal activity. Finally, we uncover that male decision-making behavior is shaped by sexual status and is regulated by npr-5. Taken together, the work portrays how shared experiences drive sex-specific plasticity in hermaphrodites and males by modulating learning to fulfill perceived evolutionary needs.