Friday 22 January 2010
to 12:00 at
Andreas Klaus (Department of Neuroscience, Karolinska Institute)
Spontaneous activity in superficial cortical layers is composed of neuronal avalanches, i.e., bursts of activity whose size distribution follows a power law with exponent alpha=-1.5 (Beggs & Plenz, J Neurosci 2003, 23(35):11167-77). Neuronal avalanches have been described in vitro and in vivo (Gireesh & Plenz, PNAS 2008, 105(21):7576-81; Petermann et al., PNAS 2009, 106(37):15921-6), and might have important implications for network function. Recent theoretical studies and findings in vitro have shown that the dynamic range of a (cortical) network is maximum at criticality (Shew et al., J Neurosci 2009, 29(49): 15595-600), and theoretical studies suggest optimum information transmission at criticality.
This talk gives in the first part an introduction to the concept of neuronal avalanches, and presents recently published results. In the second part of the talk an ongoing experimental project will be described, in which neuronal avalanches are studied in an open-loop system of cortex and striatum. Preliminary findings indicate the presence of neuronal avalanches in the striatum. It will be discussed what this could mean, for example, for the cortico-striatal information-flow.