Abstract

The dorsal raphe nucleus (DRN) is a key brainstem structure modulating motivated behaviors, such as positive and negative salience, reward processing, and defensive actions. This complexity arises from its diverse neuronal populations, including serotonergic (DRN5-HT) and dopaminergic (DRNDA) neurons. Recent studies emphasize the integration of afferent inputs and downstream targets by these subtypes, offering insights into the DRN’s orchestration of behavioral responses and its implications for psychiatric disorders marked by motivation deficits.

This symposium explores cell-type-specific and input-specific DRN interactions, focusing on how afferent inputs and neuromodulators shape circuit functions. The speakers, with a core interest in cellular and behavioral investigation of neuromodulatory circuits, utilize tools like genetic profiling, connectivity mapping, and in vivo neural activity imaging to highlight the heterogeneity of DRN5-HT subtypes, the functional interactions between DRNDA and DRN5-HT cells modulated by noradrenergic inputs, and the role of DRNDA neurons in anxiety and defensive behavior. This multidisciplinary approach addresses key questions on DRN subpopulations, neuromodulatory diversity, and behavioral impacts. By linking basic research to pathological conditions such as Parkinson’s, depression, and anxiety, the symposium bridges neuroscience and biomedical applications, appealing to researchers studying synaptic physiology, reward, and decision-making.