Biology subjects

Maurice, N.

Publications and source records attributed to Maurice, N..

8 recordsLinked to original sources

bioRxiv2026

Subthalamic Nucleus Optogenetic Inhibition Bidirectionally Regulates Social Motivation According to Familiarity and Social Hierarchy

BackgroundSocial behavior is a core component of mental health, and its disruption characterizes many neuropsychiatric disorders such as autism. Social operant paradigms enable the quantification of volitional aspects of social motivation and interactions. While sex differences have been shown to influence social motivation, factors such as familiarity and social hierarchy are also likely to play a critical role that remain insufficiently explored. In addition, the subthalamic nucleus (STN), traditionally studied in motor circuits, has emerged as an important regulator of reward and motivational processes and may contribute to social behavior processes. MethodsIn this study, we examined the influence of peer familiarity (cagemate vs. stranger) and social hierarchy (dominant vs. subordinate) 1) on operant volitional social interaction using a fixed ratio 1 (FR1) and 2) on social motivation using a progressive ratio (PR) schedule of reinforcement in non-isolated rats. To assess the causal contribution of the STN, we used optogenetic photo-inhibition during both tasks in male rats. ResultsMale rats displayed a reduction of social interest and motivation toward familiar peers, mainly driven by the social hierarchy, while female did not. STN photo-inhibition in males abolished the familiarity-driven reduction under FR1 but decreased motivation independently of familiarity or hierarchy in PR. ConclusionsThese findings highlight sex, familiarity, and hierarchy as key modulators of volitional social behavior and demonstrate a direct role of the STN in regulating social motivation. Together, they provide mechanistic insights into processes that may be disrupted in neuropsychiatric disorders characterized by social dysfunction.

neuroscience↗

bioRxiv2026

THE SUBTHALAMIC NUCLEUS IS INVOLVED IN SOCIAL MEMORY IN MALE RATS

Human social behavior depends on complex socio-cognitive abilities, many of which are disrupted in neuropsychiatric disorders. We previously found that subthalamic nucleus (STN) lesions abolish familiarity-based modulation of social reward in rats, implicating the STN in social recognition. Here, we used pharmacological lesions, electrical deep brain stimulation (DBS), and optogenetic manipulations to dissect the STNs role in social memory. STN lesions selectively impaired social discrimination memory without affecting social novelty discrimination or non-social memory. High-frequency optogenetic stimulation disrupted social discrimination memory only when applied during encoding, whereas STN optogenetic inhibition, and electrical DBS impaired social memory when applied during either encoding or retrieval. Notably, transient optogenetic inhibition abolished recognition of a cage-mate after short isolation, yet this ability was preserved after permanent lesions, suggesting compensatory adaptations. These results identify the STN as a key node for social memory and highlight the importance of considering its role in social cognition when implementing STN-targeted therapies.

neuroscience↗

bioRxiv2025

Accurate MAG reconstruction from complex soil microbiome through combined short- and HiFi long-reads metagenomics

BackgroundAdvances in high-fidelity long-read (HiFi-LR) sequencing technologies have opened new opportunities to explore the microbial genomic diversity of complex environments, such as soils. While short-read (SR) sequencing has enabled broad insights at the gene level, the limited read length constrains the reconstruction of complete genomes. HiFi-LRs, in contrast, improve assembly continuity and completeness, supporting higher-resolution taxonomic and functional annotation. However, the cost and relatively low throughput of HiFi-LR sequencing can limit genome recovery--particularly at the binning stage, where coverage depth is critical. In this study, we assess the benefit of combining HiFi-LR and SR sequencing for genome-resolved characterization of a soil microbiome. ResultsWe generated metagenomic data for a tunnel-cultivated soil sample using high coverage Illumina SRs as well as a combination of two HiFi-LR sequencing platforms (PacBio Sequel II and PacBio Revio). We found that assemblies generated from pooled HiFi-LR data alone exhibited higher completeness compared to those from ultra-deep SR data. Incorporating SR-derived coverage information for the binning of HiFi-LR contigs further increased both the number and quality of recovered metagenome-assembled genomes (MAGs), with a 24% increase in MAG recovery (313 vs. 252) and lower contamination levels (116 vs. 132 contaminated bins; mean 7.09 vs. 8.07), compared to using HiFi-LR data alone. This approach enabled the recovery of 61 additional MAGs, including 67% of low-abundance and taxonomically diverse lineages such as Archaea, representing 36 novel lineages. ConclusionOur results demonstrate that integrating HiFi-LR and SR sequencing markedly enhances genome recovery and binning accuracy in a highly diverse environment such as soil. The hybrid approach employed leverages the strengths of both technologies, leading to more contiguous assemblies and enabling the recovery of a broader range of genomes, including low-abundance and taxonomically diverse taxa. While factors such as sequencing depth, cost, and DNA quality remain important considerations, our study provides practical guidance for designing future soil metagenomics projects and underscores the value of adopting long-read technologies for more comprehensive characterization of complex microbial communities.

genomics↗

bioRxiv2025

Cocaine withdrawal enhances subthalamic reward sensitivity

High-frequency stimulation of the subthalamic nucleus (STN) has shown therapeutic potential in preclinical models of addiction. However, its rewarding properties remain unclear. Here, we show that cocaine withdrawal enhances STN intracranial self-stimulation, revealing a reward-based mechanism that may contribute to the beneficial effects of STN deep brain stimulation in addiction and related neuropsychiatric disorders.

neuroscience↗

bioRxiv2025

Mapler: Assessing assembly quality in taxonomically rich metagenomes sequenced with HiFi reads

SummaryMetagenome assembly seeks to reconstruct the most high-quality genomes from sequencing data of microbial ecosystems. Despite technological advancements that facilitate assembly, such as Hi-Fi long reads, the process remains challenging in complex environmental samples consisting of hundreds to thousands of populations. Mapler is a metagenome assembly and evaluation pipeline with a focus on evaluating the quality of Hi-Fi long read metagenome assemblies. It incorporates several state-of-the-art metrics, as well as novel metrics assessing the diversity that remains uncaptured by the assembly process. Mapler facilitates the comparison of assembly strategies and helps identify methodological bottlenecks that hinder genome reconstruction. Availability and ImplementationMapler is open source and publicly available under the AGPL-3.0 licence at https://github.com/Nimauric/Mapler. Source code is implemented in Python and Bash as a Snakemake pipeline. Contactsnicolas.maurice@inria.fr, clemence.frioux@inria.fr. Supplementary informationAvailable online.

bioinformatics↗

bioRxiv2023

SUBTHALAMIC HIGH-FREQUENCY DEEP BRAIN STIMULATION REDUCES ADDICTION-LIKE ALCOHOL USE AND SUPPRESSES THE OVERCONSUMPTION INDUCED BY THE PEER S PRESENCE

RationalThe immediate social context significantly influences alcohol consumption in humans. Recent studies have revealed that peer presence could modulate drugs use in rats. The most efficient condition to reduce cocaine intake is the presence of a stranger peer, naive to drugs. Deep brain stimulation (DBS) of the Subthalamic Nucleus (STN), which was shown to have beneficial effects on addiction to cocaine or alcohol, also modulate the protective influence of peers presence on cocaine use. ObjectivesThis study aimed to: 1) explore how the presence of an alcohol-naive stranger peer affects recreational and escalated alcohol intake, and 2) assess the involvement of STN on alcohol use and in the modulation induced by the presence of an alcohol-naive stranger peer. MethodsRats with STN DBS and control animals self-administered 10% (v/v) ethanol in presence, or absence, of an alcohol-naive stranger peer, before and after escalation of ethanol intake (observed after intermittent alcohol (20% (v/v) ethanol) access). ResultsNeither STN DBS nor the presence of an alcohol-naive stranger peer modulated significantly recreational alcohol intake. After the escalation procedure, STN DBS gradually reduced ethanol consumption. The presence of an alcohol-naive stranger peer increased consumption only in low drinkers, which effect was suppressed by STN DBS. ConclusionsThese results highlight the influence of a peers presence on escalated alcohol intake, and confirm the role of STN in addiction-like alcohol intake and in the social influence on drug consumption.

neuroscience↗

bioRxiv2023

Peer's Presence Reverses Escalated Cocaine Intake In Rats

The immediate social context critically modulates drug consumption. The presence of an unfamiliar conspecific, naive to the drug, at the time of consumption reduces cocaine self-administration in male rats during short-access sessions, as well as drug intake in human cocaine users. The subthalamic nucleus (STN), a brain structure involved in cocaine addiction and limbic processes, has been proposed to mediate such social influence on this limited level of drug intake. Whether this influence extends to escalated drug consumption remains an open question. In this study, we compared the effect of the presence of an unfamiliar peer, naive to cocaine, on cocaine self-administration in rats having been exposed to either short (2h) or long-access sessions (6h). We showed that the presence of the peer drastically reduced both limited and escalated cocaine intake in males, while it had no effect on females during short-access sessions. Assessing the effect of STN photo-inhibition or high frequency (HF) stimulation in male rats, we demonstrated that it had no effect in the absence of the conspecific in short-access sessions, STN photo-manipulation suppressed the influence of the peers presence. Moreover, STN photo-inhibition and HF stimulation decreased drug consumption in long-access sessions, but no additive effect was observed when associated with the peers presence, confirming an overriding effect of STN manipulation. Taken together, these results highlight the potential influence of socially oriented manipulations on cocaine intake and further position the STN as a critical mediator of the effect of social presence on addictive-like behaviors.

neuroscience↗

bioRxiv2021

Inhibition of cholinergic interneurons potentiates corticostriatal transmission in D1 receptor-expressing medium-sized spiny neurons and restores motor learning in parkinsonian condition

Striatal cholinergic interneurons (CINs) respond to salient or reward prediction-related stimuli after conditioning with brief pauses in their activity, implicating them in learning and action selection. This pause is lost in animal models of Parkinsons disease. How this signal regulates the functioning of the striatum remains an open question. To address this issue, we examined the impact of CIN firing inhibition on glutamatergic transmission between the cortex and the medium-sized spiny projection neurons expressing dopamine D1 receptors (D1 MSNs). Brief interruption of CIN activity had no effect in control condition whereas it increased glutamatergic responses in D1 MSNs after nigrostriatal dopamine denervation. This potentiation was dependent upon M4 muscarinic receptor and protein kinase A. Decreasing CIN firing by opto/chemogenetic strategies in vivo rescued long-term potentiation in some MSNs and alleviated motor learning deficits in parkinsonian mice. Taken together, our findings demonstrate that the control exerted by CINs on corticostriatal transmission and striatal-dependent motor-skill learning depends on the integrity of dopaminergic inputs.

neuroscience↗