STDP induced synchrony in inhibitory neural networks: theory and experiments
© Kagan et al; licensee BioMed Central Ltd. 2012
Published: 16 July 2012
Gamma rhythms have been the focus of significant research interest within the neuroscience community in recent years . Earlier theoretical studies focused on the question: how can a network of GABA containing neurons generate gamma oscillations? The findings suggest that for non-instantaneous synaptic events, inhibition rather than excitation is a better synchronizing mechanism for the generation of gamma rhythms . Synchrony in inhibitory neural networks however is extremely sensitive to intrinsic heterogeneity in the network . Based on the evidence for spike timing dependent plasticity (STDP) in inhibitory neurons [4, 5], we hypothesize that STDP of inhibitory synapses can promote robust neural synchrony in inhibitory neuronal networks in the presence of heterogeneity.
We used the dynamic clamp technique to construct a hybrid UCI network consisting of an HH based model of a inhibitory neuron coupled to a living inhibitory neuron in the stratum oriens of area CA1 of the hippocampus. Whole cell patch clamp recordings were obtained from the live cell under the following experimental protocols: (i) Fix H, vary the static synapse coupling strength g s (0) and (ii) Fix static synapse coupling strength g s (0) and vary H. In Figure 1b, we present results from the second experimental protocol. We see that as predicted by our theoretical model, the time to in phase neural synchrony in the hybrid UCI network increases with increasing heterogeneity.
We conclude that STDP of inhibitory synapses is a putative mechanism for robust neural synchrony in inhibitory neuronal networks.
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