The Distinct Subpopulations in Parafascicular Thalamic Nucleus Encoding Innate Emotional Valence

Abstract

A fundamental question in neuroscience is how animals adapt their behavior to pursue rewards and avoid punishments. Our findings demonstrate that exposure to appetitive and aversive valence stimuli enhances c-Fos expression and calcium signaling in the parafascicular thalamic nucleus (PF). We identified two distinct populations within the PF which respectively encodes appetitive or aversive emotional valence. Furthermore, we show that the subpopulations within PF projecting to ventral tegmental area (VTA) or periaqueductal gray (PAG) are anatomically segregated. And PF-VTA and PF-PAG circuits are engaged in appetitive and aversive responses, respectively. Maladaptive changes in the activity of these PF populations following stress subserve related depressive-like phenotypes and emotional valence alternations. These findings enhance our understanding of the role of the PF and its neural circuits in emotional processing, and its dysregulation in depressive disorders.

Note:
Funding Information: This research was funded by the STI2030 Major Projects (2021ZD0202804), National Natural Science Foundation of China (no. 32471068), the Key R&D Program of Shandong Province (2022ZLGX03).

Declaration of Interests: The authors declare no competing interests.

Ethics Approval Statement: Efforts were made to ensure minimal discomfort or distress to the animals. All experimental procedures adhered to the National Institutes of Health (NIH) Guide for the Care and Use of Laboratory Animals and received approval from the institutional animal care and use committee of Shandong University.

Keywords: Emotional valence, Salience, Parafascicular thalamic nucleus, Ventral tegmental area, Periaqueductal gray, Depression