RT Journal Article
SR Electronic
T1 Correlated Connectivity and the Distribution of Firing Rates in the Neocortex
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 3685
OP 3694
DO 10.1523/JNEUROSCI.4500-08.2009
VO 29
IS 12
A1 Koulakov, Alexei A.
A1 Hromádka, Tomáš
A1 Zador, Anthony M.
YR 2009
UL http://www.jneurosci.org/content/29/12/3685.abstract
AB Two recent experimental observations pose a challenge to many cortical models. First, the activity in the auditory cortex is sparse, and firing rates can be described by a lognormal distribution. Second, the distribution of nonzero synaptic strengths between nearby cortical neurons can also be described by a lognormal distribution. Here we use a simple model of cortical activity to reconcile these observations. The model makes the experimentally testable prediction that synaptic efficacies onto a given cortical neuron are statistically correlated, i.e., it predicts that some neurons receive stronger synapses than other neurons. We propose a simple Hebb-like learning rule that gives rise to such correlations and yields both lognormal firing rates and synaptic efficacies. Our results represent a first step toward reconciling sparse activity and sparse connectivity in cortical networks.