PT  - JOURNAL ARTICLE
AU  - Adriano B. L. Tort
AU  - Alfredo Fontanini
AU  - Mark A. Kramer
AU  - Lauren M. Jones-Lush
AU  - Nancy J. Kopell
AU  - Donald B. Katz
TI  - Cortical Networks Produce Three Distinct 7–12 Hz Rhythms during Single Sensory Responses in the Awake Rat
AID  - 10.1523/JNEUROSCI.6051-09.2010
DP  - 2010 Mar 24
TA  - The Journal of Neuroscience
PG  - 4315--4324
VI  - 30
IP  - 12
4099  - http://www.jneurosci.org/content/30/12/4315.short
4100  - http://www.jneurosci.org/content/30/12/4315.full
SO  - J. Neurosci.2010 Mar 24; 30
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.