Orientation column

About: Orientation column is a research topic. Over the lifetime, 1142 publications have been published within this topic receiving 130169 citations.

Visual Receptive Fields of Cells in a Cortical Area remote from the Striate Cortex in the Cat

Abstract: SEVERAL workers1–4 have reported that responses evoked either by light flash or by shock applied to the optic nerve can be recorded from a region of the suprasylvian gyrus (SSG) of the cat. These responses are similar in latency and waveform to those evoked from the primary visual area. Recent studies using the Nauta method have shown that degeneration appears in the medial wall of the suprasylvian sulcus after lesions in various parts of the visual pathway, including the lateral geniculate nucleus (LGN) (ref. 5), striate and peristriate cortex6,7. The band of degeneration is separated from visual area III by a degeneration-free zone along the apex of the suprasylvian gyrus. The experiments reported here were designed to analyse the specificity of response to visual stimuli of single neurones in the medial wall of the suprasylvian sulcus.

Cytochrome-oxidase blobs in cat primary visual cortex

Abstract: Cytochrome-oxidase blobs are central to two of the most influential ideas in contemporary visual neuroscience--cortical modularity and parallel processing pathways. In particular, the regular 2D array of cytochrome-oxidase-rich blobs in primate visual cortex is arguably the most compelling evidence for cortical modularity and has been hypothesized to mark a separate processing stream through the visual cortex. Although previously a variety of mammals have been studied, blobs have only been demonstrated in the visual cortex of primates, which has led to the conclusion that blobs represent a primate-specific feature of visual cortical organization. Here we demonstrate the presence of cytochrome-oxidase blobs in a nonprimate species. Throughout the full tangential extent of layers II-III in cat visual cortex the cytochrome-oxidase staining pattern is distinctly patchy, with the darkly stained blobs forming a regular 2D array. In addition, the blobs in cat visual cortex are functionally related to the underlying ocular dominance columns. The presence of cytochrome-oxidase blobs in the cat clearly demonstrates that they no longer can be considered a primate-specific feature of visual cortical organization.

Geniculo‐striate connections in the rabbit. II. Cytoarchitectonic structure of the striate region and of the dorsal lateral geniculate body; organization of the geniculo‐striate projections

Abstract: Retrograde changes in the dorsal lateral geniculate body were studied following cortical radiation lesios. The cytoarchitectonic structure of the striate region is described. The peristriate as well as the striate areas are shown to receive projections form the dorsal lateral geniculate body. Thus — as far as this set of connections is concerned — the peristriate are is a subdivision of the striate region. It is further shown that the striate region as defined cytoarchitectonically is —to the extent that it was validated — coextensive with the cortical projection area of the dorsal lateral geniculate body. The dorsal lateral geniculate body is divided into an alpha and a beta sector. Evidence indicates that each vertical column of cells in the striate region receives projections from an appropriate geniculate column which extends throughout the thickness of the alpha sector. The alpha cell columns project upon the striate region in an orderly manner. Details of this organization are described. The cells of the beta sector also project upon the striate region. Whether the pattern of this projection is similar to that of the alpha sector or is more generalized has not been established. Some electrophysiological and experimental-anatomical evidence relevant to the findings is discussed.