Abstract

Fast activity in neuronal networks is strongly affected by a variety of slowly acting neuromodulators. One such neuromodulator, adenosine, is known to have a suppressive effect on cells and synapses in the cortex. Its transport in tissue and action on neocortical pyramidal cells and their connections is the focus of this talk. The complex dynamics of diffusive signalling molecules in tissue is relatively poorly understood and has been somewhat neglected by the main thrust of computational neuroscience, in part because extracellular concentrations are difficult to quantify experimentally. Here recent work will first be presented on modelling the adenosine waveform, the biophysics of its measurement using microelectrode biosensors and the spatial extent of the adenosine signal in tissue. The effects of adenosine on certain cellular and synaptic components of the neocortex will then be examined. An unexpected connection will be shown between local adenosine concentrations and the development of short-term synaptic plasticity in the maturing neocortex that suggests a novel form of long-term plasticity. The work presented is in collaboration with Dr Mark Wall of the Warwick School of Life Sciences.