title: Dual mechanism of neuronal ensemble inhibition in primary auditory cortex.
abstract: Inhibition plays an essential role in shaping and refining the brain's representation of sensory stimulus attributes. In primary auditory cortex (A1), so-called "sideband" inhibition helps to sharpen the tuning of local neuronal responses. Several distinct types of anatomical circuitry could underlie sideband inhibition, including direct thalamocortical (TC) afferents, as well as indirect intracortical mechanisms. The goal of the present study was to characterize sideband inhibition in A1 and to determine its mechanism by analyzing laminar profiles of neuronal ensemble activity. Our results indicate that both lemniscal and nonlemniscal TC afferents play a role in inhibitory responses via feedforward inhibition and oscillatory phase reset, respectively. We propose that the dynamic modulation of excitability in A1 due to the phase reset of ongoing oscillations may alter the tuning of local neuronal ensembles and can be regarded as a flexible overlay on the more obligatory system of lemniscal feedforward type responses.
authors.affiliation: Cognitive Neuroscience and Schizophrenia Program, Nathan Kline Institute, Orangeburg, NY 10962, USA.
authors.forename: Monica N
authors.initials: MN
authors.lastname: O'Connell
authors.forename: Arnaud
authors.initials: A
authors.lastname: Falchier
authors.forename: Tammy
authors.initials: T
authors.lastname: McGinnis
authors.forename: Charles E
authors.initials: CE
authors.lastname: Schroeder
authors.forename: Peter
authors.initials: P
authors.lastname: Lakatos
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D001303:Auditory Cortex / Q000166:cytology* / Q000502:physiology; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D004569:Electroencephalography / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D008253:Macaca mulatta; D009424:Nervous System Physiological Phenomena; D009433:Neural Inhibition / Q000502:physiology*; D009991:Oscillometry; D011571:Psychoacoustics; D014738:Vibrissae / Q000294:innervation; D014851:Wakefulness