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Neurons in the cerebral cortex are organized into anatomical columns, with ensembles of cells arranged from the surface to the white matter. Within a column, neurons often share functional properties, such as selectivity for stimulus orientation; columns with distinct properties, such as different preferred orientations, tile the cortical surface in orderly(More)
Simple cells in the visual cortex respond to the precise position of oriented contours (Hubel and Wiesel, 1962). This sensitivity reflects the structure of the simple receptive field, which exhibits two sorts of antagonism between on and off inputs. First, simple receptive fields are divided into adjacent on and off subregions; second, within each(More)
In cortical area 17 of the cat, simple receptive fields are arranged in elongated subregions that respond best to bright (on) or dark (off) oriented contours, whereas the receptive fields of their thalamic inputs have a concentric on and off organization. This dramatic transformation suggests that there are specific rules governing the connections made(More)
Simple cells within layer IV of the cat primary visual cortex are selective for lines of a specific orientation. It has been proposed that their receptive-field properties are established by the pattern of connections that they receive from the lateral geniculate nucleus (LGN) of the thalamus. Thalamic inputs, however, represent only a small proportion of(More)
In the early visual system, neuronal responses can be extremely precise. Under a wide range of stimuli, cells in the retina and thalamus fire spikes very reproducibly, often with millisecond precision on subsequent stimulus repeats. Here we develop a mathematical description of the firing process that, given the recent visual input, accurately predicts the(More)
Hundreds of thalamic axons ramify within a column of cat visual cortex; yet each layer 4 neuron receives input from only a fraction of them. We have examined the specificity of these connections by recording simultaneously from layer 4 simple cells and cells in the lateral geniculate nucleus with spatially overlapping receptive fields (n = 221 cell pairs).(More)
In the cerebral cortex, local circuits consist of tens of thousands of neurons, each of which makes thousands of synaptic connections. Perhaps the biggest impediment to understanding these networks is that we have no wiring diagrams of their interconnections. Even if we had a partial or complete wiring diagram, however, understanding the network would also(More)
The response of a cortical cell to a repeated stimulus can be highly variable from one trial to the next. Much lower variability has been reported of retinal cells. We recorded visual responses simultaneously from three successive stages of the cat visual system: retinal ganglion cells (RGCs), thalamic (LGN) relay cells, and simple cells in layer 4 of(More)
Retinal ganglion cells and their target neurons in the principal layers of the lateral geniculate nucleus (LGN) of the thalamus have very similar, center-surround receptive fields. Although some geniculate neurons are dominated by a single retinal afferent, others receive both strong and weak inputs from several retinal afferents. In the present study,(More)
Different subtypes of GABAergic neurons in sensory cortex exhibit diverse morphology, histochemical markers, and patterns of connectivity. These subtypes likely play distinct roles in cortical function, but their in vivo response properties remain unclear. We used in vivo calcium imaging, combined with immunohistochemical and genetic labels, to record(More)