Influence of firing mechanisms on gain modulation.pdfVIP

Influence of firing mechanisms on gain modulation Ryota Kobayashi 8 Kyoto University Department of Physics, Kyoto 606-8502, Japan 0 0 E-mail: kobayashi@ton.scphys.kyoto-u.ac.jp 2 l Abstract. Neurons operate in an environment where they receive thousands of u convergent synaptic inputs. In this paper, we explore the relationship between J input current and the firing rate (f-I curve) in the presence of background synaptic 2 inputs. We find that the leaky integrate-and-fire neuron cannot reproduce the f- 1 I curves of a cortical neuron, while the leaky integrate-and-fire neuron with an adapting threshold reproduce these curves very well. These results suggest that ] cortical neurons have an adaptation mechanism and that this mechanism has some C significance for the computational capabilities of a cortical neuron. N . o i b - q [ 1 v 4 5 9 1 . 7 0 8 0 : v i X r a Influence of firing mechanisms on gain modulation 2 1. Introduction Neurons receive thousands of synaptic inputs, and these synaptic inputs are then transformed into output spike trains. A common assumption in neuroscience is that the firing rate, the average number of spikes per unit time, of a neuron conveys information and is used for computation in the brain. This assumption is supported by a number of experimental studies [1, 2, 13]. It is very important to study the relationship between the input current and the firing rate (f-I