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Axonal tracing techniques were used to examine the distribution of corticothalamic projection neurons in relation to the organization of the thalamocortical recipient zones in the whisker representation of the rat first somatic sensory cortex. Following injection of horseradish peroxidase into the physiologically defined vibrissa area in the ventrobasal(More)
We examined the pattern of cytochrome oxidase (CO), Nissl staining, and gamma-amino butyric acid (GABA) immunoreactivity in the ventroposterior lateral nucleus (VPL) of the thalamus in monkeys that received no, total, or subtotal, ablation of the hand representations in postcentral somatosensory cortex. In unoperated animals, the region of VPL representing(More)
Patients who have suffered hemiplegia from stroke may have some spontaneous recovery that is likely due to reorganization within the cerebral cortex. Understanding this physiology should be useful in devising ways to help patients have better improvement. Techniques, such as transcranial magnetic stimulation and neuroimaging with positron emission(More)
Use of short interscan interval [15O]water positron emission tomography (PET) studies reduces the overall study duration and may allow an increased number of scans for single-subject analysis of unique cases (e.g., stroke). The purpose of this study was to examine how subtraction of residual radioactivity from the previous injection (corrected scan)(More)
Spatial smoothing is a common pre-processing step in the analysis of functional brain imaging data. It can increase sensitivity to signals of specific shapes and sizes (Rosenfeld and Kak [1982]: Digital Picture Processing, vol. 2. Orlando, Fla.: Academic; Worsley et al. [1996]: Hum Brain Mapping 4:74-90). Also, some amount of spatial smoothness is required(More)
The authors recently showed that [15O]water PET data obtained with a short interscan interval (6 minutes) produced similar results whether or not the residual background from the previous scan is subtracted. The purpose of the present study was to compare scans obtained during motor activation using a short (6-minute) interscan interval protocol with those(More)
Responses of single units of area 17 were recorded in cats binocularly deprived by rearing in hoods. Neurons were recorded in pairs or in three-neuron groups with multichannel microelectrodes. Of 131 units recorded 22 percent were not visually excitable. The rest were predominantly monocularly driven. Response strength defined as the PST peak-to-background(More)
Single functional column activated by stimulation of C3 vibrissa was visualized in the mouse somatosensory cortex with 2-deo-xyglucose autoradiography. The column was cylindrical in shape and extended through the entire cortical thickness. The darkest labeling was found in layer IV, over the anatomical C3 vibrissal barrel. The functional column stretched(More)
Eight cats were binocularly deprived of pattern vision by rearing in masks from the time of eye opening. Twenty five groups of 3 neurons and 28 neuronal pairs were studied in visual orientation columns of their striate cortices. The crosscorrelograms of neuronal discharges were analyzed and the inference of underlying interneuronal connectivity was made.(More)
We present a procedure for the statistical analysis of single-subject PET data sets with a low number of scans (six total, two scans for each of three conditions) and describe the results of applying this method of analysis on the PET data of 10 normal subjects, performing a motor task, with six scans per subject. Development of this procedure, which(More)
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