Structural plasticity

Ventral pathway circuits are constituted by the interconnected brain areas that are distributed throughout the brain. They are primarily involved in processing of object related information in brain. However, their role in object recognition memory (ORM) enhancement remains unknown. In this study, we show that an activation of each of the brain areas interconnected to ventral pathway circuits individually induced enhancement in ORM; however, same treatment in brain areas not interconnected to ventral pathway circuits produced no effect. Further study in perirhinal cortex (PRh), area V2 of visu

…region which exhibits high levels of structural plasticity. Within the dorsal hippocampal CA1, specific interneuron subtypes synapse onto specific subcellular compartments of Pyramidal Neurons (PNs) such as dendrites, soma and axon initial segment (AIS) thus shaping the cellular computations underlying memory formation. Yet, very little is known about the long-term structural dynamics of these compartmentalized inhibitory synapses on PNs and their link to learning.To address these outstanding questions, we used longitudinal in viv

Neuroplasticity refers to functional and structural changes in brain regions in response to healthy and pathological activity. Neuroplasticity induced by epileptic activity can involve healthy brain regions into the epileptogenic network by perturbing their excitation/inhibition balance. Here, we present a new neural mass model that accounts for neuroplasticity and that is used to investigate the possible mechanisms underlying the epileptogenic network expansion. We formulate physiological calcium-mediated synaptic plasticity and pathological structural plasticity in a multiple-timescale frame

…of neuronal networks driven by structural plasticity. The brain's perineuronal extracellular matrix (ECM), composed mainly of chondroitin sulfate proteoglycans from the lectican family, suppresses structural plasticity in the mature brain. Several members of this family, such as aggrecan and brevican, undergo proteolytic cleavage by proteases from the ADAMTS family, which may loosen the ECM structure. Therefore, we hypothesize that activity-dependent extracellular proteolysis weakens the ECM, supporting neuronal plasticity

Prosocial and affiliative behaviors depend on intricate neuroendocrine neuronal circuits. Dynamic neuroglial interactions play pivotal roles in shaping synaptic networks, whose alterations are known to contribute to psychiatric disorders linked to social deficits. Yet the involvement of astrocytes in regulating maternal behavior remains unclear. In this study, we used a pup sensitization model with virgin pup naïve female adult mice, to investigate the molecular mechanisms underlying maternal behavior in the supraoptic nucleus. We assessed oxytocin-level in the extracellular fluid through in v

Perisynaptic astrocytic processes (PAPs) in excitatory tripartite synapses play an important role for the synaptic transmission through glutamate clearance, ions homeostasis, and synapse isolation. Here, we analyzed the proximity of PAPs to the synaptic interface at spines on the tuft dendritic branches of layer 5 pyramidal cells in the mouse primary motor cortex (M1) during a skillful motor seed reaching task (Sohn et al., 2022. Science Advances, eabm0531). Mice were trained daily for this task and in vivo imaging was conducted on days 0, 4, and 8. The animals were perfused after day 8 and ti

Vangl2, a central protein of the Wnt/PCP pathway, is a known key player in morphogenesis. One of our recent studies also linked it to the regulation of cognitive function. However, we lack information on the precise role of Vangl2 in different types of synapses associated with specific cognitive processes. Here, we found that Vangl2 is essential for the development and function of a specific hippocampal connection, the MFB/TE synapse. We show that Vangl2 is enriched in the postnatal hippocampus, specifically in the DG and CA3. Using 3D reconstruction of confocal and SBFSEM acquisitions, we sho

…Metaplasticity in which the timescale of synaptic modifications made by an individual neuron changes could resolve this flexibility-stability tradeoff. We propose that this strategy may be implemented in the olfactory bulb (OB). A striking, characte

Memories are known to reactivate during sleep. A recent modelling study (Fauth & van Rossum, eLife, 2019) could reproduce this based on self-reactivations of heavily interconnected cell assemblies and showcased its beneficial consequences for memories. However, to be maintained, the memories needed frequent reactivations such that the weights within the assemblies remain at a high level. In this work, we extend the model such that memories are maintained independently of reactivations. We suggest that long-term memories are mainly represented by the number of connections between assembly

Using a combination of in vivo imaging of neuronal circuit functional and structural dynamics, we have investigated the mechanisms by which patterned neural activity and sensory experience alter connectivity in the developing brain. We have identified, in addition to the long-hypothesized Hebbian structural plasticity mechanisms, a kind of plasticity induced by the absence of correlated firing that we dubbed “Stentian plasticity”. In the talk I will discuss the phenomenology and some mechanistic insights regarding Stentian mechanisms in brain development. Further, I will show how glia may h

…strength, mediated through the structural plasticity of the spine, are important for learning, memory, and cognitive function. Dendritic spines are small structures that contain the synapse. They come in a variety of shapes (stubby, thin, or mushroom-shaped) and a wide range of sizes that protrude from the dendrite. These spines are the regions where the postsynaptic biochemical machinery responds to the neurotransmitters. Spines are dynamic s

…that implements functional and structural plasticity from sp