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UNIVERSITY OF MALTA
LIFE SCIENCE RESEARCH SEMINARS
Web: http://www.um.edu.mt/events/scisem/
Email: [email protected]
Abstract form
Title: Paradoxical enhancement of sleep delta oscillations by partial
block of T-type Ca2+ channels: a combined computational and
in vivo study
Presenter: Dr François David
Contact address: Cardiff School of Biosciences,
Tel: +356 23402776 (direct)
Fax: +356 21310577 (fax)
Email: [email protected]
Presentation date: 11 April 2011
Abstract
The T-type Ca2+ current of thalamocortical neurons (TC) plays a key role in different
non-REM sleep waves, including slow (< 1Hz) oscillations, sleep spindles and delta
oscillations (Crunelli et al., 2005). In particular, the transient opening of T-type Ca2+
channels gives rise to low threshold Ca2+ potentials and associated high frequency
bursts of action potentials that are present during sleep spindles and delta wave. In
addition, the window component of the T-type current is essential for the generation
of the slow (< 1Hz) oscillation (Hughes et al., 2002).
However, preliminary simulations using a TC neuron model aiming at understanding
the role of the T-current in the sleep-related oscillations expressed by these neurons
have shown an unexpected increase in delta oscillations when the T-conductance is
decreased.
We have extended this modelling work and made use of the recently available,
potent and selective T-type Ca2+ channel antagonist (TTA-P2) (Shipe et al., 2008;
Dreyfus et al., 2010) to investigate the contribution of these channels to single TC
neuron oscillations and sleep EEG waves in freely moving animals.
The results show a multiple-level correlation in the dynamics of the intrinsic TC
neuron activity and the full thalamocortical network during sleep oscillation,
suggesting an important role for the thalamus in shaping the architecture of nonREM sleep oscillations.