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TY - INPR N1 - Paper was not published in 2001; certain theoretical aspects of dopamine modulation outlined in the paper, esp. on ensemble formation, remain unexplored and potentially significant. ID - cogprints8082 UR - http://cogprints.org/8082/ A1 - Scheler, Gabriele TI - Dopaminergic Regulation of Neuronal Circuits in Prefrontal Cortex Y1 - 2001/08/10/ N2 - Neuromodulators, like dopamine, have considerable influence on the processing capabilities of neural networks. This has for instance been shown in the working memory functions of prefrontal cortex, which may be regulated by altering the dopamine level. Experimental work provides evidence on the biochemical and electrophysiological actions of dopamine receptors, but there are few theories concerning their significance for computational properties (ServanPrintzCohen90,Hasselmo94). We point to experimental data on neuromodulatory regulation of temporal properties of excitatory neurons and depolarization of inhibitory neurons, and suggest computational models employing these effects. Changes in membrane potential may be modelled by the firing threshold, and temporal properties by a parameterization of neuronal responsiveness according to the preceding spike interval. We apply these concepts to two examples using spiking neural networks. In the first case, there is a change in the input synchronization of neuronal groups, which leads to changes in the formation of synchronized neuronal ensembles. In the second case, the threshold of interneurons influences lateral inhibition, and the switch from a winner-take-all network to a parallel feedforward mode of processing. Both concepts are interesting for the modeling of cognitive functions and may have explanatory power for behavioral changes associated with dopamine regulation. AV - public KW - synchronization KW - spiking neural networks KW - neuromodulation KW - dopamine KW - cortical networks KW - spike frequency adaptation KW - ensemble formation ER -