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Yann Humeau "Neuronal physiology in animal models of mental retardation".

Abstract :


Mental retardation (MR) is a common condition defined as a disability characterized by significant limitation in intellectual function and adaptive behavior that arise during childhood. MR is defined by an overall intelligence quotient lower than 70 associated with deficit in social, daily living and communication skills, and was estimated to affect 1 to 3% of the population. Causes of MR are extraordinary heterogeneous including environmental, chromosomal and monogenetic causes. To date nearly 300 MR-related genes have been identified and many of those genes are involved in brain development, neurogenesis and neuronal migration. However because some MR brains are normal in term of size and macro-architecture, it was proposed that cognitive limitations could also originate in synaptic dysfunctions.
Cognition, as other brain functions, requires an adequate treatment of sensory information, which depends on the timing of signal transfer within connected brain areas. In this track synapses constitute major “hurdles” but also provide an important source of qualitative treatment of neuronal information. Indeed, synapses are able to sense and integrate modulatory signals in order to change their response to a given input, a phenomenon called synaptic plasticity.
Our goal is to examine synaptic and neuronal functions in brains of MR mouse models, e.g. which bear point mutations often found in human patients. We focused our attention on two structures, the cerebellum and the amygdala, the first because of its pronounced post-natal development and crystalline architecture, and the second because of its synaptic plasticity repertoire and its behavioral readout.

Selected publications

X-linked mental retardation: focus on synaptic function and plasticity.
Humeau Y, Gambino F, Chelly J, Vitale N.
J Neurochem. 2009 Jan 13. [Epub ahead of print]
PMID: 19183273 [PubMed - as supplied by publisher]
    
cAMP/PKA signaling and RIM1alpha mediate presynaptic LTP in the lateral amygdala.
Fourcaudot E, Gambino F, Humeau Y, Casassus G, Shaban H, Poulain B, Lüthi A.
Proc Natl Acad Sci U S A. 2008 Sep 30;105(39):15130-5. Epub 2008 Sep 24.
PMID: 18815362 [PubMed - indexed for MEDLINE]