SLEEP 2011 Abstract Supplement

A. Basic Science IV. Neurobiology
habituation, activity of single neurons (3:1 signal: noise) was recorded in
freely-behaving rats over multiple episodes of sleep-wake.
Results: Eleven neurons in the PZ region, all of which showed either
tonic/sustained activity or phasic/burst activity during sleep and firing
rate higher than wake and REM sleep. This indicates that the PZ contains
high density of sleep active neurons. The firing frequency for these
neurons ranged from 0.2 to 2.3 Hz.
Conclusion: This study for first time has identified a sleep active area in
parafacial zone of the caudal brain stem.
Support (If Any): NS062727 and NS061841
0095
BOOSTING SK2-TYPE K + CHANNEL ACTIVITY IN THE
NUCLEUS RETICULARIS THALAMI CONSOLIDATES
NREM SLEEP
Wimmer RD 1,2 , Bond CT 3 , Adelman JP 3 , Franken P 2 , Lüthi A 1
1
Department of Cell Biology and Morphology, University of Lausanne,
Lausanne, Switzerland, 2 Center for Integrative Genomics, University
of Lausanne, Lausanne, Switzerland, 3 Vollum Institute, Oregon Health
and Science University, Portland, OR, USA
Introduction: The nucleus reticularis thalami (nRT) is known for its
pacemaking function during oscillatory brain activity related to non-rapid-eye-movement
sleep (NREMS). Small conductance type-2 (SK2) K +
channels are crucial for oscillatory bursting in nRT neurons and a loss of
SK2 channels increased NREMS fragmentation and reduced EEG delta
(1-4Hz) power during NREMS. We tested whether over-expressing SK2
channels (SK2-OE) potentiates nRT oscillatory capacity and stabilizes
NREMS.
Methods: Whole-cell patch-clamp recordings in horizontal brain slices
(300μm) were obtained from nRT and thalamocortical (TC) neurons of
SK2-OE and wild-type (WT) littermates (C57Bl/6J background, P25-
34). At P56-63, mice were implanted with EEG and EMG electrodes.
After 8-12 days of recovery, spontaneous sleep and waking behavior
was recorded for 48h.
Results: SK2-current amplitudes were >2-fold greater and oscillatory
bursting was strengthened in SK2-OE compared to WT nRT cells
(p0.05). However, SK2 channel over-expression reduced action
potential (AP) number per nRT burst and attenuated the efficacy
of unitary burst-induced inhibitory postsynaptic currents in rebound AP
generation in TC neurons (p