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Signoret-Genest, J.

Publications and source records attributed to Signoret-Genest, J..

2 recordsLinked to original sources

A viral vector model for circuit-specific synucleinopathy

In Parkinsons disease (PD), pathomechanisms such as aberrant network dysfunctions can be elucidated by conducting multiscale explorations in animal models. However, the lack of specificity in the existing models limits a restricted targeting of individual network elements and characterization of PD as a "circuitopathy". We therefore developed a cell-type specific viral vector (AAV2/9-CreON-A53T-Syn) mouse model that allows to induce synucleinopathy within individual circuit elements in vivo. When specifically targeted to dopaminergic (DA) neurons of the substantia nigra pars compacta (SNc), our approach recapitulates the main hallmarks of the disease, namely Lewy-body-like aggregation, progressive cellular and nigrostriatal projections loss, together with locomotor impairment. Our strategy is supported by new state-of-the-art analytical approaches for cell quantification and behavior characterization. Altogether, we provide a novel model of synucleinopathy, which offers new opportunities to study the contribution of individual network elements to disease pathomechanisms.

neuroscience↗

Integrated cardio-behavioural defensive states

Fear and anxiety are brain states that evolved to mediate defensive responses to threat. While it is clear that the defense reaction includes multiple interacting behavioural, autonomic and endocrine adjustments, their integrative nature is poorly understood. In particular, threat has been associated with various cardiac changes, yet a clear consensus on their relevance for the integrated defense reaction is missing. We here define rapid microstates associated with specific behaviours and heart rate dynamics, both affected by long-lasting macrostates and reflecting context-dependent threat levels. In addition, we demonstrate that one of the most commonly used defensive behavioural responses, freezing measured by immobility, is part of an integrated cardio-behavioural microstate mediated by specific midbrain circuit elements. Our work puts forth a framework for systematic integration of cardiac and behavioural readouts that presents the basis for a better understanding of complex neural defensive states and their associated systemic functions.

neuroscience↗