Simons, Daniel J.|
Professor Emeritus, Neurobiology
Ph.D., Washington University (1977)
Address: E1452 BST
203 Lothrop Street
Pittsburgh, PA 15213-2548
Sensory physiology of the cerebral cortex
Dr. Simons' laboratory investigated neuronal integration within identified, small networks of cerebral cortical neurons. Experimental approaches included single- and multi-electrode recordings, animal behavioral training, computer-based data analyses, and mathematical simulation. Studies focused on the component of the rodent somatosensory system that processes tactile information arising from the large facial vibrissae, or whiskers. Each whisker correlates one-to-one with an anatomically defined group of cortical neurons, called a barrel, that represents a morphological correlate of a functional cortical column. Barrels are local circuits that perform an initial transformation of incoming signals from the somatosensory thalamus.
Computer-controlled whisker stimuli and single cell recording techniques were used to examine how information is integrated by cortical neurons, with a strong emphasis on processing in thalamocortical circuits and the effects of corticothalamic feedback. Other studies examined the physiological and behavioral effects of abnormal tactile experiences early in life that are produced by trimming the whiskers during critical developmental stages. Computer modeling and simulations, with Dr. Bard Ermentrout, were used to understand the dynamical properties of the local circuits and their development. In collaboration with Dr. George Carvell, recordings were obtained from animals trained to perform sensorimotor tasks using their whiskers.
Thalamocortical dysfunction and thalamic injury after asphyxial cardiac arrest in developing rats.
Neural correlation is stimulus modulated by feedforward inhibitory circuitry.
Consistency of angular tuning in the rat vibrissa system.
Subbarrel patterns in somatosensory cortical barrels can emerge from local dynamic instabilities.
Effects of thalamic high-frequency electrical stimulation on whisker-evoked cortical adaptation.
Stimulus-specific and stimulus-nonspecific firing synchrony and its modulation by sensory adaptation in the whisker-to-barrel pathway.
Subthreshold receptive field properties distinguish different classes of corticothalamic neurons in the somatosensory system.
Motor modulation of afferent somatosensory circuits.
Rapid changes in thalamic firing synchrony during repetitive whisker stimulation.
Development of thalamocortical response transformation in the rat whisker-barrel system.
Thalamocortical conduction times and stimulus-evoked responses in the rat whisker-to-barrel- system.
Layer- and cell-type-specific effects of neonatal whisker-trimming in adult rat barrel cortex.
© Copyright 2001 - University
of Pittsburgh Department of Neurobiology