DOPAMINERGIC MODULATION OF GENTLE TOUCH

Gentle touch is a fundamental somatosensory modality that plays a crucial role in social interactions, emotional regulation, and well-being. While the dopaminergic (DA) system is well established in reward processing, motivation, and hedonic valuation, its role in the processing of gentle touch remains poorly understood. The nucleus accumbens (NAc), a key node of the mesolimbic DA system, integrates sensory, motivational, and emotional signals and is therefore well positioned to encode the affective value of tactile input.
We investigate how gentle stimulation is represented in the NAc and how it modulates DA signaling. Using diverse somatosensory stimulation, we monitor DA release and calcium activity in the NAc using fiber photometry, allowing real-time assessment of NAc dynamics in response to gentle touch. Complementary behavioral, physiological, and immunohistochemical approaches are used to further characterize the neural circuits involved in touch integration.
Previous results indicate that gentle touch induces robust changes in both DA release and neuronal calcium activity in the NAc, supporting a role for mesolimbic circuits in encoding the affective value of tactile stimulation. This work aims to dissect the contribution of specific peripheral sensory neuron populations to NAc responses using advanced genetic and viral strategies. In particular, C-low threshold mechanoreceptors (C-LTMRs), which are specialized sensory neurons mediating affective touch, represent a strong candidate to causally link gentle touch to dopaminergic signaling and NAc activity. Extending this framework to social contexts and neurodevelopmental disorders, such as ASD, may provide new insights into how alterations in affective touch processing contribute to social dysfunction.