Professor, Neurobiology University of Pittsburgh Phone: (412) 648-9442 Fax: (412) 648-1441 Email: cortex@pitt.edu

Ph.D., Washington University

Research Interests

Dr. Simons' research program investigates neuronal integration within identified, small networks of cerebral cortical neurons. Studies focus on the component of the somatic sensory system in rodents that processes tactile information arising from the large facial vibrissae, or whiskers. Each whisker is related one-to-one to an anatomically defined group of cortical cells, called a "barrel", that represents a morphological correlate of a functional cortical column. Computer-controlled whisker stimuli and single cell recording techniques are used to examine how information is integrated within and among these defined populations of cortical neurons. Recordings are obtained also in behaving animals trained to perform tactile discriminations.

Neurophysiological findings are incorporated into a model of sensory cortex that simulates known synaptic connections among cortical and the thalamic neurons that are presynaptic to them. Each neuron is modeled as a series of differential equations, and the model network is activated by actual pre-recorded spike trains from thalamocortical relay cells. Other studies examine the physiological and behavioral effects of abnormal tactile experience early in life, produced by trimming off the whiskers during critical developmental stages.

Trainees in Dr. Simons' laboratory will have the opportunity to combine neurophysiological and modeling studies of cortical neuronal networks.

Recent Publications

• Pinto DJ, Brumberg JC, Simons DJ: Circut Dynamics and Coding Strategies in Rodent Somatosensory Cortex. J Neurophysiol 83: 1158-1166, 2000.
• Hartings JA, Temereanca S, Simons DJ: High Responsiveness and Direction Sensitivity of Neurons in the Rat Thalamic Reticular Neucleus to Vibrissa Deflections. J Neurophysiol 83: 2791-2801, 2000.
• Kelly MK, Carvell GE, Kodger JM, Simons DJ: Sensory Loss by Selected Whisker Removal Produces Immediate Disinhibition in the Somatosensory Cortex of Behaving Rats. J Neurophysiol 19: 9117-9125, 1999.
• Brumberg JC, Pinto DJ, Simons DJ: Cortical Columnar Processing in the Rat Whisker-to-Barrel System. J Neurophysiol 82: 1808-1817, 1999.
• Carvell GE, Simons DJ. Abnormal tactile experience early in life disrupts active touch. J Neurosci 15: 2750-2757, 1996.
• Pinto DJ, Brumberg JC, Simons DJ, Ermentrout GB: A Quantitative Population Model of Whisker Barrels: Re-examining the Wilson-Cowan Equations. J Comput Neurosci 3: 247-264, 1996.