Impact of intrinsic biophysical diversity on the activity of spiking neurons

Abstract

We study the effect of intrinsic heterogeneity on the activity of a population of leaky integrate-and-fire neurons. In the high input regime, the sum of synaptic inputs to a neuron can be approximated by a fluctuating input noise, characterized by its mean and variance. By rescaling the dynamical equation, we derive mathematical relations between multiple neuronal parameters and a fluctuating input noise. To this end, common input to heterogeneous neurons is conceived as an identical noise with neuron-specific mean and variance. We identify the distinct roles of the mean and the variance for the spiking activity of a population of heterogeneous neurons. The output firing rate of a neuron is largely shaped by the mean level of the noise, whereas the distributed values of the variance give rise to different degrees of imprecise spiking (Yim et al., 2013). As a consequence, the neuronal output rates can differ considerably, and their relative spike timing becomes desynchronized. This theory can explain experimental findings from in vitro recordings (Padmanabhan and Urban, 2010).

Reference Yim MY, Aertsen A, Rotter S (2013) Impact of intrinsic biophysical diversity on the activity of spiking neurons. Phys Rev E 87: 032710. Padmanabhan K, Urban NN (2010) Intrinsic biophysical diversity decorrelates neuronal firing while increasing information content. Nat Neurosci 13(10): 1276-1282.