Anthony Holtmaat

Function: Professeur ordinaire

Group name: Structural synaptic plasticity

Group type: Main

Affiliations: Faculty of Medicine, Department of Basic Neurosciences

Domains: Sensory and Motor Systems, Development and Plasticity

Keywords: brain networks, cranial window implants, synapse, synaptic plasticity

Department of Basic Neurosciences

Research activities

Our laboratory investigates the anatomy and function of neocortical circuits, and how these are shaped by experience and learning. A central focus is understanding how synaptic plasticity — including the formation, elimination, and strengthening of connections between cortical neurons — underlies the brain’s ability to adapt to new sensory experiences and to encode perceptual learning. To address this, we combine a range of complementary techniques. Using in vivo two-photon laser scanning microscopy, we image synapses over extended periods, tracking their structural and functional organization on dendrites and axons in real time as animals undergo sensory learning or experience changes in their environment. These studies are further complemented by correlated light and electron microscopy, which links synapse dynamics with ultrastructure. In vivo and ex vivo electrophysiology and optogenetics allow us to study the interplay between higher-order feedback and lower-order feedforward inputs onto cortical pyramidal cells, and how this interaction drives synaptic integration, dendritic excitability, and long-term potentiation through mechanisms such as local dendritic plateau potentials, local regulation of ion channels, and disinhibitory circuits. Together, these approaches allow us to integrate structural and functional insights into new models of how feedback circuits shape cortical function and plasticity, and guide perceptual learning.