Memory Circuits
memory circuits
Lorenzo Fontolan
An ERC-funded postdoctoral position is available in the Cossart lab at the Mediterranean Institute of Neurobiology (INSERM, Aix-Marseille University, Marseille, France) to work in a collaborative, interdisciplinary, and friendly environment. The Cossart lab aims at understanding memory circuits in the brain and describing how they develop in health and disease. The candidate will apply their skills to extract information from our datasets, build computational models to make predictions, and work in close collaboration with experimentalists. The candidate will be co-supervised by Dr. Lorenzo Fontolan, a computational neuroscientist who recently started his research group at Inmed.
Inhibitory connectivity and computations in olfaction
We use the olfactory system and forebrain of (adult) zebrafish as a model to analyze how relevant information is extracted from sensory inputs, how information is stored in memory circuits, and how sensory inputs inform behavior. A series of recent findings provides evidence that inhibition has not only homeostatic functions in neuronal circuits but makes highly specific, instructive contributions to behaviorally relevant computations in different brain regions. These observations imply that the connectivity among excitatory and inhibitory neurons exhibits essential higher-order structure that cannot be determined without dense network reconstructions. To analyze such connectivity we developed an approach referred to as “dynamical connectomics” that combines 2-photon calcium imaging of neuronal population activity with EM-based dense neuronal circuit reconstruction. In the olfactory bulb, this approach identified specific connectivity among co-tuned cohorts of excitatory and inhibitory neurons that can account for the decorrelation and normalization (“whitening”) of odor representations in this brain region. These results provide a mechanistic explanation for a fundamental neural computation that strictly requires specific network connectivity.
The birth of hippocampal memory circuits
How development sculpts memory circuits
In mammals, the selective transformation of transient experience into stored memory occurs in the hippocampus, which develops representations of specific events in the context in which they occur. In this talk, I will focus on the development of hippocampal circuits and the self-organized dynamics embedded in them since the latter critically support the role of the hippocampus in memory. I will discuss evidence that adult hippocampal cells and circuits are remarkably sculpted by development, as early as embryonic neurogenesis. We argue that these primary developmental programs provide a scaffold onto which later experience of the external world can be grafted. Next, I will present data on the emergence of recurrent connectivity and self-organized dynamics in hippocampal circuits and outline the critical turn points and discontinuities in that developmental journey.
Brain-wide microstrokes affect the stability of memory circuits in the hippocampus
FENS Forum 2024
Cell type and synapse-specific definition of memory circuits in microbiota-deficient mice
FENS Forum 2024