The afferent connections and laminar distribution of cells in the cat striate cortex

Abstract

A laminar distribution of different functional cell types in the striate cortex of the cat is drawn up from the visual responses of single cells recorded in 64 electrode penetrations in 38 cats. In summary, S cells were found to be concentrated in laminae 4 and 6; SH cells in laminae 2, 3 and 4; C cells in laminae 5 and lower 3; B cells in laminae 3 and upper 5 and cells with non-oriented receptive fields in lamina 4. In addition, the nature of afferent innervation to striate neurons was derived from the latency of the orthodromic response to electrical stimulation in the optic chiasm and optic radiations in 19 cats. An analysis of latency values allowed the afferent innervation to a cell to be classed as belonging either to fast or slow conducting streams in the population of dLGN axons and also permitted a decision to be made on whether or not the afferent path passed directly to the cell. Direct afferent innervation from the dLGN was not found to be confined to a single class of striate neuron. Instead, examples of cells with S, SH, C, B and non-oriented receptive fields all had orthodromic latencies that met the requirement for direct innervation. Instances of cells with orthodromic latencies suggestive of indirect innervation were also found for most receptive field classes but these cells were encountered less frequently than those with a direct afferent input. It is argued that a variety of different cell types may act as first order neurons in the striate cortex and that cells occurring at later stages in the sequence of cortical processing may have been incompletely studied because they are more difficult to stimulate either visually or electrically.

Receptive Fields and Response Properties of Neurons in Layer 4 of Ferret Visual Cortex

“…Like the ferret, most neurons in layer 4 of cat visual cortex are simple cells with elongated and adjacent subregions. Unlike the ferret, cat layer 4 also contains a small population of complex cells (Gilbert 1977;Hubel and Wiesel 1962; see also Henry et al 1979)-a cell type not encountered in our sample of layer 4 ferret neurons. Although we attempted to include in our sample all neurons encountered during an electrode penetration across layer 4, it is always possible that our recordings were biased against complex cells.…”

“…As might be expected from the spatial organization of the simple cell receptive field, simple cells respond best to appropriately oriented bars or edges of light (Gilbert 1977;Henry et al 1974;Hubel and Wiesel 1962). While the receptive-field structure that defines the simple cell is characteristic for the majority of neurons in layer 4 of cat visual cortex (Gilbert 1977;Hubel and Wiesel 1962; see also Henry et al 1979), the simple cell receptive field is not universal to layer 4 in all mammals. For instance, center/surround receptive fields dominate in layer 4 of tree shrew visual cortex and establish one end of a spectrum of receptive fields encountered in layer 4C of macaque visual cortex (Blasdel and Fitzpatrick 1984;Hawken and Parker 1984;Hubel and Wiesel 1977;Kretz et al 1986;Leventhal et al 1995;Ringach et al 2002).…”

A Quantitative Map of the Circuit of Cat Primary Visual Cortex

“…For each section, the affiliation of the boutons, axonal and dendritic segments in the section to one of the five cortical layers 1, 2/3 (i.e., layers 2 and 3 where combined), 4, 5, and 6, was determined using the lamina border criteria of Henry et al (1979). The relative position of the laminar borders and the boutons and axonal and dendritic trees of all sections was summarized in a single coronal projection (see Fig.…”

Stereotypical Bouton Clustering of Individual Neurons in Cat Primary Visual Cortex

“…For each section, the affiliation of the boutons, axonal, and dendritic segments in the section to one of the five cortical layers 1, 2/3 (i.e., layers 2 and 3 where combined), 4, 5, and 6 was determined using the lamina border criteria of Henry et al (1979). The relative position of the laminar borders and the boutons, axonal, and dendritic trees of all sections was summarized in a single coronal projection (see Fig.…”