SLEEP 2011 Abstract Supplement

A. Basic Science IV. Neurobiology
(average ~21-22 microns). However, a subpopulation of mainly large
(average ~21-22 microns) GFP-positive neurons were PV-positive. In
both mouse strains PV neurons were located medially, close to the cholinergic
neurons in the horizontal limb of the diagonal band and laterally
in the magnocellular preoptic area. GFP(GABAergic)-PV-positive BF
neurons were surrounded by VAChT staining.
Conclusion: In these mutant mouse strains the distribution and size
of cholinergic, GABAergic, and GABAergic-PV-positive neurons
was broadly similar to that previously reported in the rat. GABAergic,
PV-positive neuronal activity during waking and REM sleep may be
modulated by input from neighboring BF and/or brainstem cholinergic
neurons.
Support (If Any): US Dept. of Vet. Aff., NIH MH039683 and ARRA
supplement to MH040799, Grants-in-Aids for Scientific Research from
MEXT Japan (to Y.Y.). We thank Dr. Robert Strecker for the support
of his VA MERIT grant, and his effort in providing the staff and/or resources
needed to perform the quantitative microscopy.
0086
MECHANISM BEHIND GAMMA BAND SINGLE CELL
ACTIVITY IN THE PARAFASCICULAR NUCLEUS
Hyde J 1 , Kezunovic N 1 , Simon C 1 , Urbano FJ 2 , Garcia-Rill E 1
1
Ctr. Translational Neuroscience, Univ. Arkansas Med. Sci., Little
Rock, AR, USA, 2 IFIBYNE-CONICET, University of Buenos Aires,
Buenos Aires, Argentina
Introduction: The parafascicular nucleus (Pf) is part of the “non-specific”
intralaminar thalamus involved in waking and REM sleep, during
which the EEG shows activity at gamma frequencies (~20-80Hz).
Gamma oscillations appear to participate in sensory perception, problem
solving, and memory, and this coherence may occur at cortical or subcortical
levels. We previously reported that Pf neurons fired maximally
in the gamma range (20-60Hz). The present studies tested the hypothesis
that P/Q- and N-type calcium channels are responsible for generating the
rising phase of gamma band oscillations in Pf neurons.
Methods: Single cell responses were recorded using whole-cell patch
clamp electrodes in an immersion chamber using 9-18 day old rat brainstem
slices. Recordings were made at 37°C while perfusing aCSF containing
the GABAA receptor antagonist gabazine (10 μM), the glycine
receptor antagonist strychnine (10 μM), and the glutamate receptor antagonists
CNQX (10 μM) and APV (40 μM) to block fast synaptic transmission.
Tetrodotoxin (TTX) was used to block sodium channels while
the specific calcium channel blockers, ω-agatoxin-IVA (100-200 nM)
and ω-conotoxin-GVIA (1-3 μM), were used to block P/Q- and N-type
calcium channels, respectively.
Results: Gamma band oscillations were induced in all Pf cells (n=31)
at higher amplitudes using ramps than steps (p