RT Journal Article
SR Electronic
T1 Cortical Networks Produce Three Distinct 7–12 Hz Rhythms during Single Sensory Responses in the Awake Rat
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 4315
OP 4324
DO 10.1523/JNEUROSCI.6051-09.2010
VO 30
IS 12
A1 Adriano B. L. Tort
A1 Alfredo Fontanini
A1 Mark A. Kramer
A1 Lauren M. Jones-Lush
A1 Nancy J. Kopell
A1 Donald B. Katz
YR 2010
UL http://www.jneurosci.org/content/30/12/4315.abstract
AB Cortical rhythms in the α/μ frequency range (7–12 Hz) have been variously related to “idling,” anticipation, seizure, and short-term or working memory. This overabundance of interpretations suggests that sensory cortex may be able to produce more than one (and even more than two) distinct α/μ rhythms. Here we describe simultaneous local field potential and single-neuron recordings made from primary sensory (gustatory) cortex of awake rats and reveal three distinct 7–12 Hz de novo network rhythms within single sessions: an “early,” taste-induced ∼11 Hz rhythm, the first peak of which was a short-latency gustatory evoked potential; a “late,” significantly lower-frequency (∼7 Hz) rhythm that replaced this first rhythm at ∼750–850 ms after stimulus onset (consistently timed with a previously described shift in taste temporal codes); and a “spontaneous” spike-and-wave rhythm of intermediate peak frequency (∼9 Hz) that appeared late in the session, as part of a oft-described reduction in arousal/attention. These rhythms proved dissociable on many grounds: in addition to having different peak frequencies, amplitudes, and shapes and appearing at different time points (although often within single 3 s snippets of activity), the early and late rhythms proved to have completely uncorrelated session-to-session variability, and the spontaneous rhythm affected the early rhythm only (having no impact on the late rhythm). Analysis of spike-to-wave coupling suggested that the early and late rhythms are a unified part of discriminative taste process: the identity of phase-coupled single-neuron ensembles differed from taste to taste, and coupling typically lasted across the change in frequency. These data reveal that even rhythms confined to a narrow frequency band may still have distinct properties.