TY - JOUR
T1 - Wired for social touch
T2 - the sense that binds us to others
AU - Bohic, Manon
AU - Abraira, Victoria E.
N1 - Funding Information: We thank Aman Upadhyay for helpful comments on the organization and details of this Review. The authors’ research addressing the organization and function of LTMR circuits is supported by the Pew Charitable Trust and the N.I.H. / NINDS R01 1R01NS119268-01 . Funding Information: We thank Aman Upadhyay for helpful comments on the organization and details of this Review. The authors? research addressing the organization and function of LTMR circuits is supported by the Pew Charitable Trust and the N.I.H./NINDSR01 1R01NS119268-01. Publisher Copyright: © 2021 Elsevier Ltd
PY - 2022/2
Y1 - 2022/2
N2 - The somatosensory system decodes a wide range of tactile stimuli, from touch to itch and pain, with considerable overlap and crosstalk between the pathways that relay each of those modalities. However, the most emotionally rewarding tactile sensation is that evoked by social touch: a sensation that we have missed dearly during this ongoing pandemic due to forced social isolation. How do sensory neurons detect and help us interpret the richness of social touch? What are the major skin highways for social touch and how do they shape our perception of social interactions? Here we describe the anatomical and physiological characteristics of rodent touch sensory neurons (Low Threshold Mechanoreceptors, LTMRs) and their associated spinal cord circuits responsible for translating mechanical stimuli of the skin into the neural codes of social touch perception. We propose that C-LTMRs, Aδ-LTMRs and Aβ-LTMRs represent a family of social touch mechanoreceptors, each fine tuned to detect subtle aspects of social touch interactions. Together these LTMR ensembles are the substrate of the rich world of sensations that arise from social touch. We outline the five layers of complexity that characterize each LTMR: physiological properties, peripheral terminal ending anatomy, receptive field, conduction velocities, and spinal projections. Such characteristics ensure that, although LTMR signals can converge onto common spinal interneurons, their unique temporal and physiological patterns of activation will imprint a wide variety of touch signals onto spinal networks. We also suggest a model for top-down control of spinal sensory processing where neuromodulators can finely tune the gain or the sensitivity of local spinal neurons to incoming peripheral touch information, affecting the intensity and/or the valence of the final touch representation sent to the brain.
AB - The somatosensory system decodes a wide range of tactile stimuli, from touch to itch and pain, with considerable overlap and crosstalk between the pathways that relay each of those modalities. However, the most emotionally rewarding tactile sensation is that evoked by social touch: a sensation that we have missed dearly during this ongoing pandemic due to forced social isolation. How do sensory neurons detect and help us interpret the richness of social touch? What are the major skin highways for social touch and how do they shape our perception of social interactions? Here we describe the anatomical and physiological characteristics of rodent touch sensory neurons (Low Threshold Mechanoreceptors, LTMRs) and their associated spinal cord circuits responsible for translating mechanical stimuli of the skin into the neural codes of social touch perception. We propose that C-LTMRs, Aδ-LTMRs and Aβ-LTMRs represent a family of social touch mechanoreceptors, each fine tuned to detect subtle aspects of social touch interactions. Together these LTMR ensembles are the substrate of the rich world of sensations that arise from social touch. We outline the five layers of complexity that characterize each LTMR: physiological properties, peripheral terminal ending anatomy, receptive field, conduction velocities, and spinal projections. Such characteristics ensure that, although LTMR signals can converge onto common spinal interneurons, their unique temporal and physiological patterns of activation will imprint a wide variety of touch signals onto spinal networks. We also suggest a model for top-down control of spinal sensory processing where neuromodulators can finely tune the gain or the sensitivity of local spinal neurons to incoming peripheral touch information, affecting the intensity and/or the valence of the final touch representation sent to the brain.
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U2 - https://doi.org/10.1016/j.cobeha.2021.10.009
DO - https://doi.org/10.1016/j.cobeha.2021.10.009
M3 - Review article
SN - 2352-1546
VL - 43
SP - 207
EP - 215
JO - Current Opinion in Behavioral Sciences
JF - Current Opinion in Behavioral Sciences
ER -