Accumbens

Stress has been implicated in the incidence and severity of psychiatric and gastrointestinal disorders. The immune system is capable of modulating the activity and composition of the gut following stress and vice versa. In this study we sought to examine the sequential relationship between immune signaling and microbiome composition occurring in male and female mice over time using a variable stress paradigm. Tissue was collected prior to, during, and after the stress paradigm from the same mice. Cytokines from plasma and brain were quantified using a multiplexed cytokine assay...

Itch is one of the most common clinical symptoms in patients with diseases of the skin, liver, or kidney, and it strongly triggers aversive emotion and scratching behavior. Previous studies have confirmed the role of the prelimbic cortex (Prl) and the nucleus accumbens core (NAcC), which are reward and motivation regulatory centers, in the regulation of itch. However, it is currently unclear whether the Prl-NAcC projection, an important pathway connecting these two brain regions, is involved in the regulation of itch and its associated negative emotions...

OBJECTIVE: Freezing of gait (FOG), a specific survival-threatening gait impairment, needs to be urgently explored in patients with multiple system atrophy (MSA), which is characterized by rapid progression and death within 10 years of symptom onset. The objective of this study was to explore the topological organisation of both low- and high-order functional networks in patients with MAS and FOG. METHOD: Low-order functional connectivity (LOFC) and high-order functional connectivity FC (HOFC) networks were calculated and further analysed using the graph theory approach in 24 patients with MSA without FOG, 20 patients with FOG, and 25 healthy controls...

Iboga alkaloids, also known as coronaridine congeners, have shown promise in the treatment of alcohol and opioid use disorders. The objective of this study was to evaluate the effects of catharanthine and 18-methoxycoronaridine (18-MC) on dopamine (DA) transmission and cholinergic interneurons in the mesolimbic DA system, nicotine-induced locomotor activity, and nicotine-taking behavior. Utilizing ex vivo fast-scan cyclic voltammetry (FSCV) in the nucleus accumbens core of male mice, we found that catharanthine or 18-MC differentially inhibited evoked DA release...

We previously demonstrated that a genetic single-nucleotide polymorphism (SNP, rs2304297) in the 3' untranslated region (UTR) of the human CHRNA 6 gene has sex- and genotype-dependent effects on nicotine-induced locomotion, anxiety, and nicotine + cue-induced reinstatement in adolescent rats. This study aims to investigate how the CHRNA 6 3'-UTR SNP influences dopaminergic and noradrenergic tissue levels in brain reward regions during baseline and after the reinstatement of drug-seeking behavior. Naïve adolescent and adult rats, along with those undergoing nicotine + cue reinstatement and carrying the CHRNA 6 3'-UTR SNP, were assessed for dopamine (DA), norepinephrine (NE), and metabolites in reward pathway regions...

The dorsal hippocampus (dHPC) is a key brain region for the expression of spatial memories, such as navigating towards a learned reward location. The nucleus accumbens (NAc) is a prominent projection target of dHPC and implicated in value-based action selection. Yet, the contents of the dHPC→NAc information stream and their acute role in behavior remain largely unknown. Here, we found that optogenetic stimulation of the dHPC→NAc pathway while mice navigated towards a learned reward location was both necessary and sufficient for spatial memory-related appetitive behaviors...

Basal forebrain cholinergic dysfunction, most likely linked with tau protein aggregation, is a characteristic feature of Alzheimer's disease (AD). Recent evidence suggests that tau protein is a putative target for the treatment of dementia, and the tau aggregation inhibitor, hydromethylthionine mesylate (HMTM), has emerged as a potential disease-modifying treatment. However, its efficacy was diminished in patients already receiving approved acetylcholinesterase inhibitors. In this study, we ask whether this negative interaction can also be mimicked in experimental tau models of AD and whether the underlying mechanism can be understood...

The anxiety caused by morphine protracted abstinence is considered to be an important factor contributes to drug-seeking and relapse. Endoplasmic reticulum (ER) stress plays important roles in many kinds of mental disorders including drug addiction and anxiety, but it is unclear whether ER stress is involved in anxiety-like behaviors induced by morphine withdrawal. In this study, by using behavioral test, western blot, immunofluorescence, electron transmission microscope, we found that: (1) Inhibition of endoplasmic reticulum stress by 4-Phenylbutyric acid (4-PBA) could attenuate anxiety-like behaviors induced by morphine withdrawal...

The neuronal cell adhesion molecule (NrCAM) is widely expressed and has important physiological functions in the nervous system across the lifespan, from axonal growth and guidance to spine and synaptic pruning, to organization of proteins at the nodes of Ranvier. NrCAM lies at the core of a functional protein network where multiple targets (including NrCAM itself) have been associated with schizophrenia. Here we investigated the effects of chronic unpredictable stress on latent inhibition, a measure of selective attention and learning which shows alterations in schizophrenia, in NrCAM knockout (KO) mice and their wild-type littermate controls (WT)...

Hunger increases the motivation for calorie consumption, often at the expense of low-taste appeal. However, the neural mechanisms integrating calorie-sensing with increased motivation for calorie consumption remain unknown. Agouti-related peptide (AgRP) neurons in the arcuate nucleus of the hypothalamus sense hunger, and the ingestion of caloric solutions promotes dopamine release in the absence of sweet taste perception. Therefore, we hypothesised that metabolic-sensing of hunger by AgRP neurons would be essential to promote dopamine release in the nucleus accumbens in response to caloric, but not non-caloric solutions...

Activation of the peripheral immune system contributes to stress-related neuropsychiatric symptoms. Recently in Nature, Cathomas et al. demonstrate that stress-induced social avoidance is mediated by monocyte-derived MMP8 that remodels the extracellular space of the nucleus accumbens.

BACKGROUND AND AIMS: Impaired inhibitory control accompanied by enhanced craving is hallmark of addiction. This study investigated the effects of transcranial direct current stimulation (tDCS) on response inhibition and craving in Internet gaming disorder (IGD). We examined the brain changes after tDCS and their correlation with clinical variables. METHODS: Twenty-four males with IGD were allocated randomly to an active or sham tDCS group, and data from 22 participants were included for analysis...

INTRODUCTION: Inhalant abuse is an important health issue especially among children and adolescents who often encounter these agents in the home. Research into the neurobiological targets of inhalants has lagged behind that of other drugs such as alcohol and psychostimulants. However, studies from our lab and others have begun to reveal how inhalants such as the organic solvent toluene affect neurons in key addiction related areas of the brain including the ventral tegmental area, nucleus accumbens and medial prefrontal cortex...

A major aspiration of investors is to better forecast stock performance. Interestingly, emerging "neuroforecasting" research suggests that brain activity associated with anticipatory reward relates to market behavior and population-wide preferences, including stock price dynamics. In this study, we extend these findings to professional investors processing comprehensive real-world information on stock investment options while making predictions of long-term stock performance. Using functional MRI, we sampled investors' neural responses to investment cases and assessed whether these responses relate to future performance on the stock market...

Opioid addiction is critically dependent on the activation of N‑methyl‑D‑aspartate (NMDA) receptors, which are widely found in the mesocorticolimbic system. Meanwhile, opioid addiction may affect the expression level of NMDA receptor subunits. The existence of GluN3 subunits in the NMDA receptor's tetramer structure reduces the excitatory current of the receptor channel. We evaluated the changes in the mRNA expression pattern of the GluN3B subunit of the NMDA receptor in rat brains following acute and chronic exposure to morphine...

Environmental cues, through Pavlovian learning, become conditioned stimuli that invigorate and guide animals toward acquisition of rewards. Dopamine neurons in the ventral tegmental area (VTA) and substantia nigra (SNC) are crucial for this process. Dopamine neurons are embedded in a reciprocally connected network with their striatal targets, the functional organization of which remains poorly understood. Here, we investigated how learning during optogenetic Pavlovian cue conditioning of VTA or SNC dopamine neurons directs cue-evoked behavior and shapes subregion-specific striatal dopamine dynamics...

Day length, or photoperiod, is a reliable environmental cue encoded by the brain's circadian clock that indicates changing seasons and induces seasonal biological processes. In humans, photoperiod, age, and sex have been linked to seasonality in neuropsychiatric disorders, as seen in Seasonal Affective Disorder, Major Depressive Disorder, and Bipolar Disorder. The nucleus accumbens is a key locus for the regulation of motivated behaviors and neuropsychiatric disorders. Using periadolescent and young adult male and female mice, here we assessed photoperiod's effect on serotonin and dopamine tissue content in the nucleus accumbens core, as well as on accumbal synaptic dopamine release and uptake...

Humans and other animals exhibit aversive behavioral and emotional responses to unequal reward distributions compared with their conspecifics. Despite the significance of this phenomenon, experimental animal models designed to investigate social inequity aversion and delve into the underlying neurophysiological mechanisms are limited. In this study, we developed a rat model to determine the effects of socially equal or unequal reward and stress on emotional changes in male rats. During the training session, the rats were trained to escape when a sound cue was presented, and they were assigned to one of the following groups: all escaping rats [advantageous equity (AE)], freely moving rats alongside a restrained rat [advantageous inequity (AI)], all restrained rats [disadvantageous equity (DE)], and a rat restrained in the presence of freely moving companions [disadvantageous inequity (DI)]...

RATIONALE: In 2018, the International Classification of Diseases (ICD-11) classified Gaming Disorder (GD) as a mental disorder. GD mainly occurs among adolescents, who, after developing addiction, show psychopathological traits, such as social anxiety, depression, social isolation, and attention deficit. However, the different studies conducted in humans so far show several limitations, such as the lack of demographic heterogeneity and equal representation of age, differences in the type of game and in the follow-up period...

The nucleus accumbens (NAc) is a central component of the brain circuitry that mediates motivated behavior, including reward processing. Since the rewarding properties of social stimuli have a vital role in guiding behavior (both in humans and nonhuman animals), the nucleus accumbens is likely to contribute to the brain circuitry controlling social behavior. In rodents, prior studies have found that focal pharmacological inhibition of NAc and/or elevation of dopamine in NAc increases social interactions. However, the role of the NAc in social behavior in nonhuman primates remains unknown...