Frontiers in neuroscience
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Frontiers in neuroscience · Jan 2014
ReviewMonocyte trafficking to the brain with stress and inflammation: a novel axis of immune-to-brain communication that influences mood and behavior.
HIGHLIGHTSPsychological stress activates neuroendocrine pathways that alter immune responses. Stress-induced alterations in microglia phenotype and monocyte priming leads to aberrant peripheral and central inflammation. Elevated pro-inflammatory cytokine levels caused by microglia activation and recruitment of monocytes to the brain contribute to development and persistent anxiety-like behavior. ⋯ Evidence from various rodent models, including repeated social defeat (RSD), revealed that trafficking of monocytes to the brain promoted the establishment of anxiety-like behaviors following prolonged stress exposure. In addition, new evidence implicates monocyte trafficking from the spleen to the brain as key regulator of recurring anxiety following exposure to prolonged stress. The purpose of this review is to discuss mechanisms that cause stress-induced monocyte re-distribution in the brain and how dynamic interactions between microglia, endothelial cells, and brain macrophages lead to maladaptive behavioral responses.
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This review presents an overview of the use of music therapy in neurological early rehabilitation of patients with coma and other disorders of consciousness (DOC) such as unresponsive wakefulness syndrome (UWS) or minimally conscious state (MCS). There is evidence that patients suffering from UWS show emotional processing of auditory information, such as listening to speech. Thus, it seems reasonable to believe that music listening-as part of an enriched environment setting-may be of therapeutic value in these patients. ⋯ These studies should consider a precise clinical definition and homogeneity of the patient cohort with respect to the quality (coma vs. UWS vs. MCS), duration (rather weeks to months than days) and cause (traumatic vs. non-traumatic) of DOC, a standardized intervention protocol, valid clinical outcome parameters over a longer observation period (weeks to months), monitoring of neurophysiological and vegetative parameters and, if available, neuroimaging to confirm diagnosis and to demonstrate responses and functional changes in the patients' brains.
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Frontiers in neuroscience · Jan 2014
ReviewGABAB receptor ligands for the treatment of alcohol use disorder: preclinical and clinical evidence.
The present paper summarizes the preclinical and clinical studies conducted to define the "anti-alcohol" pharmacological profile of the prototypic GABAB receptor agonist, baclofen, and its therapeutic potential for treatment of alcohol use disorder (AUD). Numerous studies have reported baclofen-induced suppression of alcohol drinking (including relapse- and binge-like drinking) and alcohol reinforcing, motivational, stimulating, and rewarding properties in rodents and monkeys. ⋯ The recent identification of a positive allosteric modulatory binding site, together with the synthesis of in vivo effective ligands, represents a novel, and likely more favorable, option for pharmacological manipulations of the GABAB receptor. Accordingly, data collected to date suggest that positive allosteric modulators of the GABAB receptor reproduce several "anti-alcohol" effects of baclofen and display a higher therapeutic index (with larger separation-in terms of doses-between "anti-alcohol" effects and sedation).
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Brainstem and hypothalamic "orexigenic/anorexigenic" networks are thought to maintain body weight homeostasis in response to hormonal and metabolic feedback from peripheral sites. This approach has not been successful in managing over- and underweight patients. It is suggested that concept of homeostasis has been misinterpreted; rather than exerting control, the brain permits eating in proportion to the amount of physical activity necessary to obtain food. ⋯ As the physical price of food approaches zero, eating and body weight increase without constraints. Conversely, in anorexia nervosa body weight is homeostatically regulated, the high level of physical activity in anorexia is displaced hoarding for food that keeps body weight constantly low. A treatment based on this point of view, providing patients with computerized mealtime support to re-establish normal eating behavior, has brought 75% of patients with eating disorders into remission, reduced the rate of relapse to 10%, and eliminated mortality.
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Frontiers in neuroscience · Jan 2014
Neural correlates of short-term memory in primate auditory cortex.
Behaviorally-relevant sounds such as conspecific vocalizations are often available for only a brief amount of time; thus, goal-directed behavior frequently depends on auditory short-term memory (STM). Despite its ecological significance, the neural processes underlying auditory STM remain poorly understood. To investigate the role of the auditory cortex in STM, single- and multi-unit activity was recorded from the primary auditory cortex (A1) of two monkeys performing an auditory STM task using simple and complex sounds. ⋯ The data suggest that early match suppression occurs in both A1 and the dTP, whereas later match enhancement occurs first in the PFC, followed by A1 and later in dTP. Because match enhancement occurs first in the PFC, we speculate that enhancement observed in A1 and dTP may reflect top-down feedback. Overall, our findings suggest that A1 forms part of the larger neural system recruited during auditory STM.