Alan C Rosenquist

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The location and retinotopic organization of visual areas in the cat cortex were determined by systematically mapping visual cortex in over 100 cats. The positions of the receptive fields of single neurons or small clusters of neurons were related to the locations of the corresponding recording sites in the cortex to determine the representations of the(More)
The location and retinotopic organization of areas 18 and 19 in cat cortex were determined using electrophysiological mapping techniques. These two areas each contain a single representation of the visual hemifield and each has a distinctive cytoarchitecture. The visual hemifield representations in these two areas are nearly mirror images of each other.(More)
This is the second in a series of papers in which we describe our continuing efforts to define functional units of visual cortex based upon electro-physiological mapping of single and multiple unit activity in both awake and the nitrous oxide anesthetized cats. In the first paper (Tusa, Palmer and Rosenquist, '78), the extent and retinotopic organization of(More)
A deficiency in the noradrenergic system of the brain, originating largely from cells in the locus coeruleus (LC), is theorized to play a critical role in the progression of a family of neurodegenerative disorders that includes Parkinson's disease (PD) and Alzheimer's disease (AD). Consideration is given here to evidence that several neurodegenerative(More)
The present report describes the patterns of cat thalamocortical interconnections for each of the 13 retinotopically ordered visual areas and additional visual areas for which no retinotopy has yet emerged. Small injections (75 nl) of a mixture of horseradish peroxidase and [3H]leucine were made through a recording pipette at cortical injection sites(More)
The interconnections among visual areas in cat cortex were studied with respect to the specific laminae in which the cortically projecting neurons are located. Single injections of HRP were made through recording micropipettes into nine different visual areas. In 15 cortical areas the laminar distribution of neurons which were retrogradely filled with HRP(More)
Transection of the commissure of the superior colliculus restores visual orientation behavior to a cat previously rendered hemianopic by a unilateral visual cortical lesion (the Sprague effect). Using two methods, we asked whether this recovery resulted from the severing of the tectotectal component of the commissure or whether the destruction of some other(More)
The cortical interconnections of 17 visual areas in the cat were studied by making single injections through recording micropipettes of the neuroanatomical tracers 3H-leucine and horseradish peroxidase (HRP) into the visual cortex of 40 adult animals. Coronal sections from each of the brains were analyzed for location of silver grains and HRP-filled(More)
Transection of non-tectotectal fibers in the caudal one-half of the commissure of the superior colliculus restores visual orienting to a cat previously rendered hemianopic by a large unilateral visual cortical lesion. Other observations related to this recovery phenomenon (i.e., the Sprague effect) have suggested that the caudal commissural fibers whose(More)
The distribution of neurons projecting through the corpus callosum (callosal neurons) was examined in retinotopically defined areas of cat visual cortex. As many callosal neurons as possible were labeled in a single animal by surgically dividing the posterior two-thirds of the corpus callosum and exposing the cut ends of callosal axons to horseradish(More)