Evolutionary appearance of von Economo's neurons in the mammalian cerebral cortex.

von Economo’s neurons (VENs) are large, spindle-shaped projection neurons in layer V of the frontoinsular (FI) cortex, and the anterior cingulate cortex. During human ontogenesis, the VENs can first be differentiated at late stages of gestation, and increase in number during the first eight postnatal months. VENs have been identified in humans, chimpanzee, bonobos, gorillas, orangutan and, more recently, in the macaque. Their distribution in great apes seems to correlate with human-like social cognitive abilities and self-awareness. VENs are also found in whales, in a number of different cetaceans, and in the elephant. This phylogenetic distribution may suggest a correlation among the VENs, brain size and the “social brain.” VENs may be involved in the pathogenesis of specific neurological and psychiatric diseases, such as autism, callosal agenesis and schizophrenia. VENs are selectively affected in a behavioral variant of frontotemporal dementia in which empathy, social awareness and self-control are seriously compromised, thus associating VENs with the social brain. However, the presence of VENs has also been related to special functions such as mirror self-recognition. Areas containing VENs have been related to motor awareness or sense-of-knowing, discrimination between self and other, and between self and the external environment. Along this line, VENs have been related to the “global Workspace” architecture: in accordance the VENs have been correlated to emotional and interoceptive signals by providing fast connections (large axons = fast communication) between salience-related insular and cingulate and other widely separated brain areas. Nevertheless, the lack of a characterization of their physiology and anatomical connectivity allowed only to infer their functional role based on their location and on the functional magnetic resonance imaging data. The recent finding of VENs in the anterior insula of the macaque opens the way to new insights and experimental investigations

A subcortical network for implicit visuo-spatial attention:Implications for Parkinson's disease

Recent studies in humans and animal models suggest a primary role of the basal ganglia in the extraction of stimulus-value regularities, then exploited to orient attentional shift and build up sensorimotor memories. The tail of the caudate and the posterior putamen both receive early visual input from the superficial layers of the superior colliculus, thus forming a closed-loop. We portend that the functional value of this circuit is to manage the selection of visual stimuli in a rapid and automatic way, once sensory-motor associations are formed and stored in the posterior striatum. In Parkinson's Disease, the nigrostriatal dopamine depletion starts and tends to be more pronounced in the posterior putamen. Thus, at least some aspect of the visuospatial attention deficits observed since the early stages of the disease could be the behavioral consequences of a cognitive system that has lost the ability to translate high-level processing in stable sensorimotor memories. (C) 2021 The Authors. Published by Elsevier Ltd

Traumatic experiences and somatoform dissociation in women with fibromyalgia

Objective: Psychological factors like traumatic life events seem to affect the etiopathogenesis and the exacerbation of fibromyalgia (FM), a chronic widespread musculoskeletal pain syndrome. This Study investigated the prevalence of traumatic events, with a particular attention to the whole life span, and both psychoform and somatoform dissociation in patients with FM, compared with healthy controls (HC). In addition, the possible effects of traumatic events and dissociative experiences on FM symptoms have been analyzed. Method: Traumatic experiences, dissociative symptoms, and psychological distress were assessed in 99 consecutive patients with FM and 107 healthy women. Student t-tests for two independent samples were used to determine differences between the FM and HC groups. A hierarchical multiple regression analysis was used to explore the possible contribution of trauma and dissociation to FM symptoms. Results: Results revealed that the levels of both somatoform and psychoform dissociation were higher among patients with FM than HC (p < .001). Moreover, patients with FM experienced significantly more negative life events than HC (p < .001). Finally, the data suggested that the severity of FM disabilities was significantly predicted by the presence of depressive symptoms, somatoform dissociation, cumulative trauma, and educational level. The final Model explained 40% of the variance. Conclusions: Results suggest that the construct of somatoform dissociation could serve as a useful framework to improve our understanding of FM symptoms, and stressed the importance of evaluating the effects of multiple traumas in cumulative form because this has substantial implications for the evaluation and treatment of patients. (PsycInfo Database Record (c) 2021 APA, all rights reserved)