How does the olfactory system represent stimulus dynamics? We demonstrate how the neuron-intrinsic mechanism of spike-frequency adaptation (SFA) shapes response dynamics at successive stages of the
olfactory network. At the periphery (input layer), the SFA conductance of the olfactory receptor neuron (ORN) model leads to an initial peak response and subsequent adaptation to the steady state firing, matching experimental observations (e.g. Nagel and Wilson, 2010). The effect of adaptation becomes progressively pronounced across sequential network stages and temporal sparseness in the KCs develops naturally in the adaptive network model. The stimulus onset results in a sparse response of average 1-2 spikes, which qualitatively and quantitatively matches the experimental observations (e.g. Ito et al., 2008). Importantly, the single neuron as well as the KC population response are highly reliable since SFA suppresses response variability (Farkhooi, Müller & Nawrot, 2011) and thus provides a substrate for the formation of stable associative memories (Strube-Bloss, Nawrot, & Menzel, 2011).
Donders Discussions 2013, Donders Institute for Brain, Radboud University Nijmegen