Are inhibitory synaptic conductances on thalamic relay neurons
inhomogeneous? Are synapses from individual afferents clustered?
Mike Neubig and Alain Destexhe
Neurocomputing 32-33: 213-218, 2000.
Standard and dynamic current clamps were used to emulate dendritic GABA-Aergic
postsynaptic currents (IPSCs) in a reconstructed thalamic relay neuron. The
variability of somatically recorded single events was an order of magnitude
smaller than reported in experimental work, suggesting that experimentally
observed variability of miniature IPSCs reflects variable synaptic strength
rather than filtering. Additionally, to evoke physiologic unitary-IPSCs at 0.8
probability-of-release, it was necessary to partially cluster synapses. This
induced nonlinear summation-bringing unitary amplitudes down to the observed
range. We conclude that synaptic strength is inhomogeneous and that inhibitory
afferents might form synapses in clusters.
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