ELSC Seminar Series

Homeostatic plasticity describes the compensatory mechanisms that regulate activity levels in the brain during ongoing changes, for example following learning, environmental changes or input loss. To examine how mechanisms of homeostatic plasticity are implemented in vivo, we have developed in vivo proxies to measure plasticity mechanisms in the visual cortex of adult mice that undergo sensory deprivation following input loss. These approaches use a combination of in vivo two-photon imaging of structural and functional plasticity in behaving mice at the level of individual spines up to networks of neurons, together with electrophysiology and immunohistochemistry. Using these novel approaches, we have shown that homeostatic mechanisms in vivo are implemented at many spatial scales – from subsets of individual synapses that receive intrinsic cortical inputs, to within individual dendritic branches, to across small networks of dozens of cells. Further, we find that the local circuitry of a neuron and the network in which the neuron is embedded, in addition to homeostatic synaptic mechanisms, play an important role in homeostatic recovery of activity. Together, our work suggests an important role of the network in homeostatic compensation in vivo.