Intra-visceral insular cortex 2-arachidonoylglycerol, but not N-arachidonoylethanolamide, suppresses acute nausea-induced conditioned gaping in rats

Background: Humans are neurobiologically wired for touch receptivity. Social touch is a common and mutual way of expressing affection, care, and intimacy. From an evolutionary perspective, affiliative and affectionate touch are considered necessary for social and cognitive development throughout life-stages and across species. The emergence of the COVID-19 pandemic as a public health threat has mandated social distancing as a measure to contain the global outbreak. Travel restrictions, lockdown, and quarantine have led to separation and segregation, giving rise to social touch deprivation that might have adverse biopsychosocial consequences. Methods: Affective touch has rarely been discussed within the purview of social psychiatry. We attempted to review the neurobiological, social, and behavioural correlates of social and sexual touch, as well as the neurophysiological models involved. Results: The unmyelinated peripheral C-fibre afferents projecting to insular cortex and somatosensory areas form the prime pathway for affective touch. ‘Top-down’ modulation via the periaqueductal grey area, rostroventral medulla and sub-cortical structures, and ‘Bottom-up’ approach via the dorsal horn of the spine form the two theoretical models of ‘social touch’ system. The mu - opioid receptor (MOR) implicated in the Brain Opioid Theory of Social Attachment (BOTSA) and social neuropeptides like oxytocin and vasopressin are the primary neurochemical substrates involved. Sexual intimacy involves other neurotransmitters, with increased oxytocin activity in the limbic structures, Nucleus Accumbens, Anterior Cingulate, and Prefrontal Cortex. The discrimination and amalgamation of touch senses, their affiliative value and emotional valence in humans are based on a complex interplay between psychobiological, environmental, and personal factors. Conclusion: The neurobehavioral and emotional effects of ‘touch hunger’ and strategies to mitigate it during COVID-19 are discussed in the context of psychoneuroimmunity and stress.

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Clinical presentation of strokes confined to the insula: a systematic review of literature

Neurological Sciences ◽

10.1007/s10072-021-05109-1 ◽

2021 ◽

Author(s):

Vincenzo Di Stefano ◽

Maria Vittoria De Angelis ◽

Chiara Montemitro ◽

Mirella Russo ◽

Claudia Carrarini ◽

...

Keyword(s):

Systematic Review ◽

Clinical Presentation ◽

Insular Cortex ◽

Affective Processing ◽

Appropriate Treatment ◽

Insula Cortex ◽

Atypical Presentations ◽

High Level ◽

To Receive ◽

Insular Region

Abstract Background and purpose The insular cortex serves a wide variety of functions in humans, ranging from sensory and affective processing to high-level cognition. Hence, insular dysfunction may result in several different presentations. Ischemic strokes limited to the insular territory are rare and deserve a better characterization, to be quickly recognized and to receive the appropriate treatment (e.g. thrombolysis). Methods We reviewed studies on patients with a first-ever acute stroke restricted to the insula. We searched in the Medline database the keywords “insular stroke” and “insular infarction”, to identify previously published cases. Afterwards, the results were divided depending on the specific insular region affected by the stroke: anterior insular cortex (AIC), posterior insular cortex (PIC) or total insula cortex (TIC). Finally, a review of the clinical correlates associated with each region was performed. Results We identified 25 reports including a total of 49 patients (59.7 ± 15.5 years, 48% male) from systematic review of the literature. The most common clinical phenotypes were motor and somatosensory deficits, dysarthria, aphasia and a vestibular-like syndrome. Atypical presentations were also common and included dysphagia, awareness deficits, gustatory disturbances, dysautonomia, neuropsychiatric or auditory disturbances and headache. Conclusions The clinical presentation of insular strokes is heterogeneous; however, an insular stroke should be suspected when vestibular-like, somatosensory, speech or language disturbances are combined in the same patient. Further studies are needed to improve our understanding of more atypical presentations.

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