Effect of The Ratio of Inhibitory and Excitatory Conductance on The Regularity of Spontaneous Cortical Activity
M Özer, Muhammet Uzuntarla, Lyle J. Graham
proceeding (Uluslararası, Hakemli) | Yazar(lar): M Özer, Muhammet Uzuntarla, Lyle J. Graham | Yıl: 2008 | Dergi/Kurum: ANALYSIS OF BIOMEDICAL SIGNALS AND IMAGES | İndeks: WOS.ISTP — Özet: Cortical neurons in vivo can operate in a continuum between low-conductance (LC) and high-conductance (HC) states. We investigate ho
Cortical neurons in vivo can operate in a continuum between low-conductance (LC) and high-conductance (HC) states. We investigate how changing the ratio, r, of the mean inhibitory conductance to a fixed value of the mean excitatory conductance affects the regularity of spontaneous cortical firing between the two extreme states. We show that, in general, spike regularity becomes smaller for larger r, thus as the neuron approaches the HC state. Furthermore, in the HC state, spike regularity consistently increases with an increase of the synaptic input variability, whereas with small r, thus LC states, regularity first decreases and then increases with an increase in the input variability. We suggest that this qualitative difference may reflect a state-dependent dominance of spike output driven by the average membrane potential, versus that driven by fluctuations in the membrane potential.