title: Compression and reflection of visually evoked cortical waves.
abstract: Neuronal interactions between primary and secondary visual cortical areas are important for visual processing, but the spatiotemporal patterns of the interaction are not well understood. We used voltage-sensitive dye imaging to visualize neuronal activity in rat visual cortex and found visually evoked waves propagating from V1 to other visual areas. A primary wave originated in the monocular area of V1 and was "compressed" when propagating to V2. A reflected wave initiated after compression and propagated backward into V1. The compression occurred at the V1/V2 border, and local GABAA inhibition is important for the compression. The compression/reflection pattern provides a two-phase modulation: V1 is first depolarized by the primary wave, and then V1 and V2 are simultaneously depolarized by the reflected and primary waves, respectively. The compression/reflection pattern only occurred for evoked waves and not for spontaneous waves, suggesting that it is organized by an internal mechanism associated with visual processing.
authors.affiliation: Department of Physiology and Biophysics, Georgetown University Medical Center, Washington, DC 20057, USA. wuj@georgetown.edu
authors.forename: Weifeng
authors.initials: W
authors.lastname: Xu
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Huang
authors.forename: Kentaroh
authors.initials: K
authors.lastname: Takagaki
authors.forename: Jian-young
authors.initials: JY
authors.lastname: Wu
mesh_terms: D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D003627:Data Interpretation, Statistical; D004562:Electrocardiography; D004594:Electrophysiology; D005074:Evoked Potentials, Visual / Q000502:physiology; D018756:GABA Antagonists / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D010775:Photic Stimulation; D051381:Rats; D020318:Rats, Long-Evans; D013003:Somatosensory Cortex / Q000502:physiology; D013239:Stereotyped Behavior / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*
chemical_list: D018756:GABA Antagonists; D001640:Bicuculline