Logo image
Sex-specific regulation and neural representations of social behavior in a corticothalamic circuit
Dissertation   Open access

Sex-specific regulation and neural representations of social behavior in a corticothalamic circuit

Nancy Rose Mack
Doctor of Philosophy (Ph.D.), Drexel University
Dec 2022
DOI:
https://doi.org/10.17918/00001413
pdf
Mack_Nancy_20223.73 MBDownloadView

Abstract

Neurosciences Neural circuitry Prefrontal cortex Thalamus Mice as laboratory animals Social behavior
Social behaviors are fundamental to our survival and well-being and are also disrupted in numerous psychiatric disorders such as depression, anxiety, and schizophrenia. Although a robust body of work indicates that the prefrontal cortex (PFC) plays an important role in regulating social interactions, how the PFC communicates with other brain regions to exert top-down control over social behaviors remains elusive. The PFC sends dense projections to the paraventricular nucleus of the thalamus (PVT), and recent work has demonstrated that this neural circuit can support behavioral responses to salient, emotionally-relevant cues. Therefore, we hypothesized that PFC projections to the PVT may play an essential role in regulating behavior during a social encounter. To explore this, we first utilized an intersectional chemogenetic approach to evaluate the behavioral consequences of exciting or inhibiting neural activity in the PFC[right arrow]PVT circuit. We found that excitation of this pathway significantly reduced social interaction in male mice, yet increased social interaction in female mice. Further, we recapitulated these results in males by selectively activating PFC axon terminals in the PVT, demonstrating that optical activation can reduce social interaction when time-locked to the entry of the social chamber. Finally, we utilized fiber photometry to monitor changes to PFC[right arrow]PVT neural activity while mice explored a novel conspecific or a novel object. In male mice, we found that PFC[right arrow]PVT neurons are inhibited during the onset of social investigation but not object investigation. In contrast, PFC[right arrow]PVT neurons in female mice showed a significant increase in activity exclusively during social approach. Thus, the PFC[right arrow]PVT circuit conveys distinct social information in males versus females that is critical for social interaction in a sex-dependent manner.

Metrics

44 File views/ downloads
47 Record Views

Details

Logo image