Using whole-cell recordings and optogenetic stimulation of presynaptic input in anaesthetized mice, we show that synaptic plasticity rules are gated by cortical dynamics. Up states are biased towards depression such that presynaptic stimulation alone leads to synaptic depression, while connections contributing to postsynaptic spiking are protected against this synaptic weakening. We find that this novel activity-dependent and input-specific downscaling mechanism has two important computational advantages: 1) improved signal-to-noise ratio, and 2) preservation of previously stored information. Thus, these synaptic plasticity rules provide an attractive mechanism for SWS-related synaptic downscaling and circuit refinement. We simulate a feedforward network of neurons undergoing Up-state-mediated plasticity. Under this plasticity rule, presynaptic spikes alone lead to synaptic depression, whereas those followed by postsynaptic spikes within 10 ms are not changed.
Cell Type(s): Abstract integrate-and-fire leaky neuron
Model Concept(s): Synaptic Plasticity; STDP; Sleep; Homeostasis
Simulation Environment: Python
Implementer(s): Pedrosa, Victor [v.pedrosa15 at imperial.ac.uk]
References:
González-Rueda A, Pedrosa V, Feord RC, Clopath C, Paulsen O. (2018). Activity-Dependent Downscaling of Subthreshold Synaptic Inputs during Slow-Wave-Sleep-like Activity In Vivo. Neuron. 97 [PubMed]