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Neuroscientific research on pleasant touch has focused on the C-tactile pathway for gentle stroking and has successfully explained how these sensory fibers transmit information about affective social touch to the brain and induce sensations of pleasantness. The C-tactile social/affective touch hypothesis even proposes that C-tactile fibers form a privileged pathway underlying social touch. However, deep pressure is a type of touch commonly considered pleasant and calming, occurring in hugs, cuddling, and massage. In this paper we introduce a paradigm for studying pleasant deep pressure and propose that it constitutes another important form of social touch. We describe development of the oscillating compression sleeve (OCS) as one approach to administering deep pressure and demonstrate that this touch is perceived as pleasant and calming. Further, we show that deep pressure can be imaged with functional magnetic resonance imaging (MRI) using the air-pressure-driven OCS and that deep pressure activates brain regions highly similar to those that respond to C-tactile stroking, as well as regions not activated by stroking. We propose that deep pressure constitutes another social touch pathway of evolutionary importance signaling the close proximity of conspecifics.

Schizophrenia is a severe neuropsychiatric disorder with core features including hallucinations, delusions, and cognition deficits. Accumulating evidence has implicated abnormal DNA methylation in the development of schizophrenia. However, the mechanisms by which DNA methylation changes alter the risk for schizophrenia remain largely unknown. We recently carried out a DNA methylome study of peripheral blood samples from 469 first-episode patients with schizophrenia and 476 age- and gender-matched healthy controls of Han Chinese origin. Genomic DNA methylation patterns were quantified using an Illumina Infinium Human MethylationEPIC BeadChip. We identified multiple differentially methylated positions (DMPs) and regions between patients and controls. The most significant DMPs were annotated to genes C17orf53, THAP1 and KCNQ4 (KV7.4), with Bonferroni-adjusted P values of [Formula: see text], [Formula: see text], and [Formula: see text], respectively. In particular, KCNQ4 encodes a voltage-gated potassium channel of the KV7 family, which is linked to neuronal excitability. The genes associated with top-ranked DMPs also included many genes involved in nervous system development, such as LIMK2 and TMOD2. Gene ontology analysis of the differentially methylated genes further identified strong enrichment of neuronal networks, including neuron projection extension, axonogenesis and neuron apoptotic process. Finally, we provided evidence that schizophrenia-associated epigenetic alterations co-localize with genetic susceptibility loci. By focusing on first-episode schizophrenia patients, our investigation lends particularly strong support for an important role of DNA methylation in schizophrenia pathogenesis unconfounded by the effects of long-term antipsychotic medication or disease progression. The observed DNA methylation aberrations in schizophrenia patients could potentially provide a valuable resource for identifying diagnostic biomarkers and developing novel therapeutic targets to benefit schizophrenia patients.

A strong body of evidence supports a role for immune dysregulation across many psychiatric disorders including depression, the leading cause of global disability. Recent progress in the search for genetic variants associated with depression provides the opportunity to strengthen our current understanding of etiological factors contributing to depression and generate novel hypotheses. Here, we provide an overview of the literature demonstrating a role for immune dysregulation in depression, followed by a detailed discussion of the immune-related genes identified by the most recent genome-wide meta-analysis of depression. These genes represent strong evidence-based targets for future basic and translational research which aims to understand the role of the immune system in depression pathology and identify novel points for therapeutic intervention., Highlights • Dysregulated immune function has been strongly linked to depression. • Recent genome-wide association studies support this relationship. • These genes represent strong candidates for etiological and translational research.

Depression is the world's leading cause of disability. Greater understanding of the neurobiological basis of depression is necessary for developing novel treatments with improved efficacy and acceptance. Recently, major advances have been made in the search for genetic variants associated with depression which may help to elucidate etiological mechanisms. The present review has two major objectives. First, we offer a brief review of two major biological systems with strong evidence for involvement in depression pathology: neurotransmitter systems and the stress response. Secondly, we provide a synthesis of the functions of the 269 genes implicated by the most recent genome-wide meta-analysis, supporting the importance of these systems in depression and providing insights into other possible mechanisms involving neurodevelopment, neurogenesis, and neurodegeneration. Our goal is to undertake a broad, preliminary stock-taking of the most recent hypothesis-free findings and examine the weight of the evidence supporting these existing theories and highlighting novel directions. This qualitative review and accompanying gene function table provides a valuable resource and guide for basic and translational researchers, with suggestions for future mechanistic research, leveraging genetics to prioritize studies on the neurobiological processes involved in depression etiology and treatment.

The sensation of pressure allows us to feel sustained compression and body strain. While our understanding of cutaneous touch has grown significantly in recent years, how deep tissue sensations are detected remains less clear. Here, we use quantitative sensory evaluations of patients with rare sensory disorders, as well as nerve blocks in typical individuals, to probe the neural and genetic mechanisms for detecting non-painful pressure. We show that the ability to perceive innocuous pressures is lost when myelinated fiber function is experimentally blocked in healthy volunteers and that two patients lacking Aβ fibers are strikingly unable to feel innocuous pressures at all. We find that seven individuals with inherited mutations in the mechanoreceptor PIEZO2 gene, who have major deficits in touch and proprioception, are nearly as good at sensing pressure as healthy control subjects. Together, these data support a role for Aβ afferents in pressure sensation and suggest the existence of an unknown molecular pathway for its detection., The mechanisms underlying deep pressure sensing are not fully understood. Here the authors demonstrate that while two individuals lacking Aβ fibers demonstrate impaired deep pressure sensing, seven individuals with PIEZO2 loss of function mutations display normal deep pressure responses.

OBJECTIVE: To explore the relations between trauma exposure and anxiety and depression among college students, and to determine whether trait mindfulness may moderate these relations. PARTICIPANTS: Self-report survey data from 2,336 college sophomores was drawn from a larger university-wide study (“Spit for Science”). METHODS: We constructed multiple linear regression models using past-year trauma exposure, trait mindfulness, and their multiplicative interaction to predict current anxiety and depressive symptom severity, while controlling for covariates. RESULTS: Mindfulness was associated with lower levels of depression and anxiety symptom severity. Trauma was a significant predictor of anxiety, but not depression, and high levels of mindfulness attenuated the association between trauma exposure and higher anxiety symptom severity. CONCLUSIONS: These results have implications for the treatment and prevention of anxiety among trauma-exposed college students and provides a basis for further research into the mechanisms through which mindfulness may facilitate positive mental health.

Both light skin stroking (engaging the C-tactile afferent sensory pathway) and deep pressure touch (as in deep tissue massage) are commonly perceived as pleasant and relaxing. Opioid blockade has been found to increase receipt of grooming in monkeys, suggesting possible opioid modulation of touch pleasantness. Recently, human data [1] suggested that blocking opioid receptors might decrease the perceived intensity of gentle brushing but increase its pleasantness. The current study examined the role of endogenous opioids in the perceived intensity and pleasantness of pleasant touch. Using a double-blind cross-over design, 24 healthy adult participants received intravenous naloxone or saline (control) on separate days. Blocks of gentle brushing and deep pressure compression were administered on the lower left calf. Participants rated the intensity and pleasantness of each stimulus, as well as current mood and anxiety. Naloxone significantly reduced perceived intensity of gentle brushing (p = 0.039), but did not affect brushing pleasantness (p = 0.44) or intensity or pleasantness of deep pressure (p = 0.97; p = 0.85). The naloxone-induced reduction in gentle touch intensity replicates results previously seen in chronic pain patients [1]. The lack of effect on pleasantness in this study versus [1] could relate to differences in the location of touch (arm or leg), sex of the experimenters, or whether the touch followed pain tasks. However, in the current study, naloxone was marginally anxiolytic (p = 0.07), and naloxone-induced changes in touch pleasantness were significantly more correlated with subsequent mood and anxiety ratings than were changes during saline (mood p = 0.04; anxiety p