The phase response of the cortical slow oscillation

Abstract

Cortical slow oscillations occur in the mammalian brain during deep sleep and have been shown to contribute to memory consolidation, an effect that can be enhanced by electrical stimulation. As the precise underlying working mechanisms are not known it is desired to develop and analyze computational models of slow oscillations and to study the response to electrical stimuli. In this paper we employ the conductance based model of Compte et al. (J Neurophysiol 89:2707-2725, 2003) to study the effect of electrical stimulation. The population response to electrical stimulation depends on the timing of the stimulus with respect to the state of the slow oscillation. First, we reproduce the experimental results of electrical stimulation in ferret brain slices by Shu et al. (Nature 423:288-293, 2003) from the conductance based model. We then numerically obtain the phase response curve for the conductance based network model to quantify the network's response to weak stimuli. Our results agree with experiments in vivo and in vitro that show that sensitivity to stimulation is weaker in the up than in the down state. However, we also find that within the up state stimulation leads to a shortening of the up state, or phase advance, whereas during the up-down transition a prolongation of up states is possible, resulting in a phase delay. Finally, we compute the phase response curve for the simple mean-field model by Ngo et al. (EPL Europhys Lett 89:68002, 2010) and find that the qualitative shape of the PRC is preserved, despite its different mechanism for the generation of slow oscillations.

Dynamics of the thalamo-cortical system driven by pulsed sensory stimulation

“…The model aims at reproducing evoked responses of auditory and visual stimuli at several frequencies. We extend previous results on the phase-dependent response of isolated cortex [9] to stimuli which are time-locked to spindle and slow oscillation events and test the hypothesis that the main factor determining thalamic gating properties in non-REM sleep is the phase of the cortical slow oscillation.…”

Computer simulations of synchrony and oscillations evoked by two coherent inputs

“…Taken together, periodic spatiotemporal patterns will be better than populational modulation as a method of information transmission in oscillatory waves. Since the populational modulation is stable at lower frequency and robust for aperiodic noises, it might be fit for ready state like an idling (Weigenand et al 2012). Actually, in the simulations, the input spikes with both properties, i.e.…”

Sleep, neuroengineering and dynamics

“…In this direction, Clopath (2012) compares two recently proposed mechanisms, namely tagtrigger consolidation, and a metastate tagging model, and provides a comprehensive comparison of both concepts. Finally, Weigenand et al (2011Weigenand et al ( , 2012 investigate the phase-dependence of stimulation of cortical slow waves. It would be highly interesting, based on improved understanding of neural coding and plasticity mechanisms, to design specific stimulation protocols that selectively strengthen desired acquired memories.…”