Functional organization of the cat visual cortex in relation to the representation of a uniform surface.
Neuronal activity in the early visual cortex has been extensively studied from the standpoint of contour representation. On the other hand, representation of the interior of a surface surrounded by a contour is much less well understood. Several studies have identified neurons activated by a uniform surface covering their receptive fields, but their distribution within the cortex is not yet known. The aim of the present study was to obtain a better understanding of the distribution of such neurons in the visual cortex. Using optical imaging of intrinsic signals, we found that there are a group of surface-responsive regions located in area 18, along the area 17/18 border, that tend to overlap the singular points of the orientation-preference map. Extracellular recordings confirmed that neurons responsive to uniform plane stimuli are accumulated in these regions. Such neurons also existed outside the surface-responsive regions around the singular points. These results suggest that there exists a functional organization related to the representation of a uniform surface in the early visual cortex.
Tani
Toshiki
T
Laboratory of Neural Control, National Institute for Physiological Sciences, Okazaki-shi, Aichi, 444-8585, 351-0198, Japan.
Yokoi
Isao
I
Ito
Minami
M
Tanaka
Shigeru
S
Komatsu
Hidehiko
H
D000818:Animals; D016477:Artifacts; D001931:Brain Mapping / Q000379:methods*; D002415:Cats; D004594:Electrophysiology; D009474:Neurons / Q000502:physiology*; D055095:Optics and Photonics; D009949:Orientation / Q000502:physiology; D010775:Photic Stimulation; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*