Biology subjects

Amiez, C.

Publications and source records attributed to Amiez, C..

5 recordsLinked to original sources

bioRxiv2025

Motivational control is implemented by a cingulo-prefrontal pathway

The neuronal connections between the midcingulate cortex (MCC) and the dorsolateral prefrontal cortex (dlPFC) are associated with multiple cognitive functions, including rapid and long-term adaptive processes. Here we show that DREADD-mediated activation of MCC to dlPFC projection in macaques led to increased engagement in a foraging task, but did not alter their trial-to-trial adaptive strategy. We conclude that a critical role for MCC-dlPFC pathway is in the temporally extended control of behaviour rather than in rapid adaptation.

neuroscience↗

bioRxiv2024

Brain Charts for the Rhesus Macaque Lifespan

Recent efforts to chart human brain growth across the lifespan using large-scale MRI data have provided reference standards for human brain development. However, similar models for nonhuman primate (NHP) growth are lacking. The rhesus macaque, a widely used NHP in translational neuroscience due to its similarities in brain anatomy, phylogenetics, cognitive, and social behaviors to humans, serves as an ideal NHP model. This study aimed to create normative growth charts for brain structure across the macaque lifespan, enhancing our understanding of neurodevelopment and aging, and facilitating cross-species translational research. Leveraging data from the PRIMatE Data Exchange (PRIME-DE) and other sources, we aggregated 1,522 MRI scans from 1,024 rhesus macaques. We mapped non-linear developmental trajectories for global and regional brain structural changes in volume, cortical thickness, and surface area over the lifespan. Our findings provided normative charts with centile scores for macaque brain structures and revealed key developmental milestones from prenatal stages to aging, highlighting both species-specific and comparable brain maturation patterns between macaques and humans. The charts offer a valuable resource for future NHP studies, particularly those with small sample sizes. Furthermore, the interactive open resource (https://interspeciesmap.childmind.org) supports cross-species comparisons to advance translational neuroscience research.

neuroscience↗

bioRxiv2021

Frontal cortical functional connectivity is impacted by anaesthesia in macaques

AO_SCPLOWBSTRACTC_SCPLOWA critical aspect of neuroscience is to establish whether and how brain networks evolved across primates. To date, most comparative studies have used resting-state functional Magnetic Resonance Imaging (rs-fMRI) in anaesthetized non-human primates and in awake humans. However, anaesthesia strongly affects rs-fMRI signals. The present study investigated the impact of the awareness state (anaesthesia vs. awake) within the same group of macaque monkeys on the rs-fMRI functional connectivity (FC) organization of a well characterized network in the human brain, the cingulo-frontal lateral network. Results in awake macaques revealed a similar FC pattern to that previously uncovered in the human brain. Rostral seeds in the cingulate sulcus exhibited stronger correlation strength with rostral compared to caudal lateral frontal cortical areas while caudal seeds in the cingulate sulcus displayed stronger correlation strength with caudal compared to anterior lateral frontal cortical areas. Critically, this inverse rostro-caudal functional gradient was abolished under anaesthesia. This study demonstrates that the FC pattern of cingulo-frontal cortical networks is preserved from macaque to human but some of its properties can only be observed in the awake state, warranting significant caution when comparing FC patterns across species under different states.

neuroscience↗

bioRxiv2019

Cognitive control of orofacial and vocal responses in the human frontal cortex

The frontal cortical areas critical for human speech production, i.e. the ventrolateral frontal cortex (cytoarchitectonic areas 44 and 45; VLF) and the dorsomedial frontal cortex (DMF) comprising the mid-cingulate cortex (MCC) and the pre-supplementary motor area (preSMA), exist in non-human primates and are implicated in cognitive vocal control functions. The present functional neuroimaging study seeks to define the basic roles of these VLF-DMF network regions in primate vocal production and how they might have been adapted for human speech. We demonstrate that area 44 and the MCC are respectively involved in the cognitive selection of orofacial, non-speech vocal and verbal responses, and the feedback-driven adaptation of these responses - roles that are likely preserved across primates. In contrast, area 45 and preSMA have roles that are specific to human speech: area 45 contributes to active verbal retrieval during learning, while preSMA is involved in processing verbal feedback during orofacial/vocal adaptations.

neuroscience↗

bioRxiv2018

The human ventromedial prefrontal cortex sulcal morphology and its influence on its functional organization.

The ventromedial prefrontal cortex (vmPFC), which comprises several distinct cytoarchitectonic areas, is a key brain region supporting decision-making processes and it has been shown to be one of the main hubs of the Default Mode Network, a network classically activated during resting state. We here examined the inter-individual variability in the vmPFC sulcal morphology in 57 humans (37 females) and demonstrated that the presence/absence of the inferior rostral sulcus and the subgenual intralimbic sulcus influences significantly the sulcal organization of this region. Furthermore, the sulcal organization influences the location of the vmPFC peak of the Default Mode Network, demonstrating that the location of functional activity can be affected by local sulcal patterns. These results are critical for the investigation of the function of the vmPFC and show that taking into account the sulcal variability might be essential to guide the interpretation of neuroimaging studies.\n\nSIGNIFICANCE STATEMENTThe ventromedial prefrontal cortex (vmPFC) is one of the main hubs of the Default Mode Network and plays a central role in value coding and decision-making. The present study provides a complete description of the inter-individual variability of anatomical morphology of this large portion of prefrontal cortex and its relation to functional organization. We have shown that two supplementary medial sulci predominantly determine the organization of the vmPFC, which in turn affect the location of the functional peak of activity in this region. Those results show that taking into account the variability in sulcal patterns might be essential to guide the interpretation of neuroimaging studies of the human brain and of the vmPFC in particular.

neuroscience↗