Affective touch in the context of development, oxytocin signaling, and autism

Abstract

Touch represents one of our most important senses throughout life and particularly in the context of our social and emotional experiences. In this review, we draw on research on touch processing from both animal models and humans. Firstly, we briefly describe the cutaneous touch receptors and neural processing of both affective and discriminative touch. We then outline how our sense of touch develops and summarize increasing evidence demonstrating how essential early tactile stimulation is for the development of brain and behavior, with a particular focus on effects of tactile stimulation in infant animals and pediatric massage and Kangaroo care in human infants. Next, the potential mechanisms whereby early tactile stimulation influences both brain and behavioral development are discussed, focusing on its ability to promote neural plasticity changes and brain interhemispheric communication, development of social behavior and bonding, and reward sensitivity through modulation of growth factor, oxytocin, and opioid signaling. Finally, we consider the implications of evidence for atypical responses to touch in neurodevelopmental disorders such as autism spectrum disorder and discuss existing evidence and future priorities for establishing potential beneficial effects of interventions using massage or pharmacological treatments targeting oxytocin or other neurochemical systems.

Autonomic and hedonic response to affective touch in autism spectrum disorder

“…Given the considerable heterogeneity within the spectrum, future studies may benefit from including individuals with lower levels of functioning. Secondly, in light of our results, further investigation should address the well-known controversy surrounding the coexistence of both hypo-and hyper-autonomic sensory activation in the ASD population (Li et al, 2022), recognizing the observed dissociation between implicit and explicit levels of ASD experience. Thirdly, as in our study we obtained a sample composed of young ASD participants only, it would be important for future research to investigate the behavioral and autonomic activities related to affective touch in elderly subjects.…”

Oxytocin administration enhances pleasantness and neural responses to gentle stroking but not moderate pressure social touch by increasing peripheral concentrations

“…These findings support the conclusion that exogenously administered OT selectively facilitates neural and behavioral responses to stimulation of CT fibers during social touch via peripheral-mediated routes rather than by direct entry into the brain. Touch and massage interventions are increasingly demonstrated to have beneficial effects on brain development and function and it is likely that their effects on OT release and signaling play a major role in this ( Li et al, 2022 ). Our findings demonstrating that OT treatment can facilitate behavioral and brain responses to gentle social touch/massage therefore may have important translational therapeutic implications for using OT-based interventions in individuals with aberrant responses to social touch such as in autism.…”

Insecure Attachment, Oxytocinergic System and C Tactile Fibers: An Integrative and Translational Pathophysiological Model of Fibromyalgia and Central Sensitization Syndromes

“…In this line, it has been demonstrated that OT acts synergistically with the dopaminergic afferents of the mesocorticolimbic regions and with the opioidergic tachykinin + neurons of the reward system and more specifically of the lateral and ventrolateral PAG [123,131,137,138].…”

“…Affective touch (AT) and the related CT fibers represent a fundamental functional system for the development of the newborn's brain and, according to some evidence, also for that of the fetus [121][122][123]. It is known that the somatosensory system is almost completely mature by the 32nd week of pregnancy, with the exception of the insula and the superior temporal sulcus, two cortical regions involved in social cognition that become operational around 2-3 months and 12 months of age respectively [123]. It is interesting to note that it has been hypothesized that already in this gestational period the CT fibers may have a regulatory function on the maturation and differentiation of the "affective tactile system".…”