Synchronizing Back-propagation Activated Calcium Spikes: A Model forAttentional Control
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2015-08-17
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en
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Abstract
Recent experiments show that synchronized burst firing plays an important role in attentional control. It was
found that during attentional control, bursts in the prefrontal cortex (PFC) synchronized with the local field
potential (LFP) from distant brain areas. Back-propagation activated calcium spikes (BACs), a dendritic
mechanism elicited by the coincidence of a back-propagating somatic action potential and input at the tuft,
could be a new explanation for attentional control. BACs could implement the selection of relevant sensory
information by acting as a coincidence detector of sensory information received at the proximal somatic
dendrites and feedback information reflecting its relevance received at the tuft. To inform distant brain areas
about the relevant sensory information BACs could be synchronized by oscillatory inhibition from Martinotti
cells and in turn excite distant Martinotti cells that project the oscillation to pyramidal cells downstream.
In this modeling study we investigated (i) the firing rate, degree of phase-locking and the ratio of BACs
of a multi-compartment pyramidal cell model for varying frequencies of oscillatory inhibition and (ii) the
characteristics of a network model representing two different brain areas developed to reproduce the
experimental findings with an emphasis on the synchronization induced by BAG bursts between brain areas.
By varying the frequency of the oscillatory inhibition we found a resonance in the firing rate of the pyramidal
cell model at low frequencies that resulted from synchronized bursting. These bursts were predominantly
elicited by BACs when the excitatory input was equally distributed to the basal dendrite and tuft and were
highly phase locked. In the network model we could reproduce the observation that synchronization of
activity in one area to the LFP in another was associated with bursts. These findings yield new insights about
the possible role of synchronized BAG bursts in attentional control. Not only couid BAG bursts implement the
selection of relevant sensory information, they could also couple to distant brain areas by synchronization.
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Faculteit der Sociale Wetenschappen