-
Mashup Score: 0Two-brain microstates: A novel method for quantifying task-driven inter-brain asymmetry - 16 hour(s) ago
Joint action and interpersonal coordination between individuals are integral parts of daily life, and various behavioral tasks have been designed to study their emergence and maintenance. One example is the mirror-game paradigm, which examines the dynamics of two people improvising motion together. However, the underlying neural mechanisms remain poorly understood, and inter-brain methods underdeveloped. Previously, we reported unique individual behavioral and neural signatures of performing actions when observed by others using a mirror-game paradigm. Here, we explored inter-brain synchronization during the mirror-game paradigm using a novel approach employing two-brain EEG microstates. Microstates are quasi-stable configurations of brain activity that have been reliably replicated across studies, and proposed to be basic buildings blocks for mental processing. Expanding the microstate methodology to dyads of interacting participants (two-brain microstates) enables us to investigate q
Source: www.biorxiv.orgCategories: General Medicine News, General HCPsTweet
-
Mashup Score: 0Experience-dependent, sexually dimorphic synaptic connectivity defined by sex-specific cadherin expression - 16 hour(s) ago
We describe here the molecular mechanisms by which juvenile experience defines patterns of sexually dimorphic synaptic connectivity in the adult nervous system of the nematode C. elegans. We show that starvation of juvenile males disrupts serotonin dependent activation of the CREB transcription factor in a nociceptive sensory neuron, PHB. CREB acts through a cascade of transcription factors to control expression of an atypical cadherin protein, FMI-1/Flamingo. During postembryonic development, FMI-1/Flamingo has the capacity to promote and maintain synaptic connectivity of the PHB nociceptive sensory to a command interneuron, AVA, in both sexes, but the serotonin transcriptional regulatory cassette antagonizes FMI-1/Flamingo expression in males, thereby establishing sexually dimorphic connectivity between PHB and AVA. A critical regulatory node in this process is the CREB-target LIN-29, a Zn finger transcription factor which integrates four different layers of information: sexual speci
Source: www.biorxiv.orgCategories: General Medicine News, General HCPsTweet
-
Mashup Score: 0Chronic fluoxetine treatment desensitizes serotoninergic inhibition of GABA inputs and the intrinsic excitability of dorsal raphe serotonin neurons - 16 hour(s) ago
Dorsal raphe serotonin (5-hydroxytryptamine, 5-HT) neurons are spontaneously active and release 5-HT that is critical to normal brain function such mood and emotion. Serotonin reuptake inhibitors (SSRIs) increase the synaptic and extracellular 5-HT level and are effective in treating depression. Treatment of two weeks or longer is often required for SSRIs to exert clinical benefits. The cellular mechanism underlying this delay was not fully understood. Here we show that the GABAergic inputs inhibit the spike firing of raphe 5-HT neurons; this GABAergic regulation was reduced by 5-HT, which was prevented by G-protein-activated inwardly rectifying potassium (Girk) channel inhibitor tertiapin-Q, indicating a contribution of 5-HT activation of Girk channels in GABAergic presynaptic axon terminals. Equally important, after 14 days of treatment of fluoxetine, a widely used SSRI type antidepressant, this 5-HT inhibition of GABAergic inputs was substantially downregulated. Furthermore, the chr
Source: www.biorxiv.orgCategories: General Medicine News, General HCPsTweet
-
Mashup Score: 0Reinforcement learning when your life depends on it: a neuro-economic theory of learning - 16 hour(s) ago
Synaptic plasticity enables animals to adapt to their environment, but memory formation can consume a substantial amount of metabolic energy, potentially impairing survival. Hence, a neuro-economic dilemma arises whether learning is a profitable investment or not, and the brain must therefore judiciously regulate learning. Indeed, in experiments it was observed that during starvation, Drosophila suppress formation of energy-intensive aversive memories. Here we include energy considerations in a reinforcement learning framework. Simulated flies learned to avoid noxious stimuli through synaptic plasticity in either the energy expensive long-term memory (LTM) pathway, or the decaying anesthesia-resistant memory (ARM) pathway. The objective of the flies is to maximize their lifespan, which is calculated with a hazard function. We find that strategies that switch between the LTM and ARM pathways based on energy reserve and reward prediction error, prolong lifespan. Our study highlights the
Source: www.biorxiv.orgCategories: General Medicine News, General HCPsTweet
-
Mashup Score: 0Impact Of Learned Helplessness On Cognitive Performance And Resting-State Connectivity: An fMRI Study - 16 hour(s) ago
Learned helplessness (LH) is the phenomenon of resignation in the face of a problematic situation and is caused by the feeling of lacking control in a situation due to internal or external factors. This means that an individual does not seek to resolve the situation they are confronted with and consciously or unconsciously chooses to be passive. The Dorsal Raphe Nucleus (DRN) core could be at the root of the persistent action of the LH phenomenon and influences regions such as the striatum and amygdala. It is thought that the LH phenomenon could affect self-perception and it has been shown that the default mode network (DMN) is often associated with self-reflection during the resting state (RS) phase. It is therefore possible that LH influences both self-perception and the DMN. Based on previous studies, we investigated how LH affects participants. We used functional MRI (fMRI) to test this hypothesis. Participants were divided into two groups, subjected to solvable (control group), an
Source: www.biorxiv.orgCategories: General Medicine News, General HCPsTweet
-
Mashup Score: 1Oseltamivir (Tamiflu), a Commonly Prescribed Antiviral Drug, Mitigates Hearing Loss in Mice - 16 hour(s) ago
Hearing loss affects up to 10% of all people worldwide, but currently there is only one FDA-approved drug for its prevention in a subgroup of cisplatin-treated pediatric patients. Here, we performed an unbiased screen of 1,300 FDA-approved drugs for protection against cisplatin-induced cell death in an inner ear cell line, and identified oseltamivir phosphate (brand name Tamiflu), a common influenza antiviral drug, as a top candidate. Oseltamivir phosphate was found to be otoprotective by oral delivery in multiple established cisplatin and noise exposure mouse models. The drug conferred permanent hearing protection of 15-25 dB SPL for both female and male mice. Oseltamivir treatment reduced in mice outer hair cells death after cisplatin treatment and mitigated cochlear synaptopathy after noise exposure. A potential binding protein, ERK1/2, associated with inflammation, was shown to be activated with cisplatin treatment and reduced by oseltamivir cotreatment in cochlear explants. Import
Source: www.biorxiv.orgCategories: General Medicine News, General HCPsTweet
-
Mashup Score: 0Quick, Don't Move!: Wh-Movement and Wh-In-Situ Structures in Rapid Parallel Reading - EEG studies in English, Urdu, and Mandarin Chinese - 16 hour(s) ago
A fundamental question in the cognitive neuroscience of language is how grammatical representations are reflected in the organization and activity of the brain. This is challenging in part because superficial differences between languages, e.g., word order, exert different demands on the memory systems that process these structures. Here, we present an electroencephalography (EEG) study to investigate the brain’s responses to wh-constructions in English, Urdu, and Mandarin Chinese. In addition to the different word orders, writing systems, and morphological typologies of the 3 languages, these languages diverge with regard to how wh-constructions are formed: English requires filler-gap dependencies for wh-objects, whereas Urdu and Mandarin Chinese do not. We use a rapid parallel reading task, in which short sentences are displayed in parallel for 200ms to mitigate the different demands placed on memory systems. We show that neural responses distinguish wh-object constructions from thei
Source: www.biorxiv.orgCategories: General Medicine News, General HCPsTweet
-
Mashup Score: 0Dynamic Accumbal Overrepresentation of Reward Cues in Food- and Opioid-Seeking Rats after Prenatal THC Exposure - 16 hour(s) ago
The increasing prevalence of cannabis use during pregnancy has raised significant medical concerns, primarily related to the presence of Δ9-tetrahydrocannabinol (THC), which readily crosses the placenta and impacts fetal brain development. Previous research has identified midbrain dopaminergic neuronal alterations related to maternal THC consumption. However, the enduring consequences that prenatal cannabis exposure (PCE) has on striatum-based processing during voluntary reward pursuit have not been specifically determined. Here, we characterize PCE rats during food (palatable pellets) or opioid (remifentanyl)-maintained reward seeking. We find that the supra motivational phenotype of PCE rats is independent of value-based processing and is instead related to augmented reinforcing efficiency of opioid rewards. Our findings reveal that in utero THC exposure leads to increased cue-evoked dopamine release responses and an overrepresentation of cue-aligned, effort-driven striatal patterns
Source: www.biorxiv.orgCategories: General Medicine News, General HCPsTweet
-
Mashup Score: 0α-Synuclein Conformations in Plasma Distinguish Parkinson′s Disease from Dementia with Lewy Bodies - 16 hour(s) ago
Spread and aggregation of misfolded α-synuclein (aSyn) within the brain is the pathologic hallmark of Lewy body diseases (LBD), including Parkinson′s disease (PD) and dementia with Lewy bodies (DLB). While evidence exists for multiple aSyn protein conformations, often termed ″strains″ for their distinct biological properties, it is unclear whether PD and DLB result from aSyn strain differences, and biomarkers that differentiate PD and DLB are lacking. Moreover, while pathological forms of aSyn have been detected outside the brain (e.g., in skin, gut, blood), the functional significance of these peripheral aSyn species is unclear. Here, we developed assays using monoclonal antibodies selective for two different aSyn species generated in vitro — termed Strain A and Strain B — and used them to evaluate human brain tissue, cerebrospinal fluid (CSF), and plasma, through immunohistochemistry, enzyme-linked immunoassay, and immunoblotting. Surprisingly, we found that plasma aSyn species detec
Source: www.biorxiv.orgCategories: General Medicine News, General HCPsTweet
-
Mashup Score: 0Resiliency to Alzheimer's disease neuropathology can be distinguished from dementia using cortical astrogliosis imaging - 16 hour(s) ago
Despite the presence of significant Alzheimer’s disease (AD) pathology, characterized by amyloid β (Aβ) plaques and phosphorylated tau (pTau) tangles, some cognitively normal elderly individuals do not inevitably develop dementia. These findings give rise to the notion of cognitive ‘resilience’, suggesting maintained cognitive function despite the presence of AD neuropathology, highlighting the influence of factors beyond classical pathology. Cortical astroglial inflammation, a ubiquitous feature of symptomatic AD, shows a strong correlation with cognitive impairment severity, potentially contributing to the diversity of clinical presentations. However, noninvasively imaging neuroinflammation, particularly astrogliosis, using MRI remains a significant challenge. Here we sought to address this challenge and to leverage multidimensional (MD) MRI, a powerful approach that combines relaxation with diffusion MR contrasts, to map cortical astrogliosis in the human brain by accessing sub-voxe
Source: www.biorxiv.orgCategories: General Medicine News, General HCPsTweet
Two-brain microstates: A novel method for quantifying task-driven inter-brain asymmetry https://t.co/zDzU2hbHJg #bioRxiv