Neural Processing of Somatic Sensation
Our research focuses on two aspects of mammalian nervous systems. One set of studies explores the functional organization of afferent systems transmitting the signals of the fine diameter, peripheral sensory nerve fibers, particularly those related to pain. The other concerns pathophysiological changes in the phenotype of primary afferent neurons.
At the peripheral level we have identified the functional and structural characteristics of afferent neurons signaling noxious events (stimuli that injure or are capable of injuring tissue) through electrophysiological recordings from single afferent fibers. Single afferent fibers have been labeled intracellularly by marker substances to elucidate the structure and distribution of their terminations. Presently, we are determining the organization of the spinal neurons receiving direct synaptic input from the central terminals of these primary neurons. Whole cell patch recordings are used to examine synaptic characteristics of neurons in the superficial portions of the spinal dorsal horn in vitro from slice preparations of mammalian spinal cord. We identify synaptic agents and molecular features related to functional subsets of spinal sensory neurons using pharmacological and histochemical techniques. Neuronal circuitry in the spinal dorsal horn is being explored by simultaneous recordings from two neurons and by using transgenic mice expressing flourescent proteins in particular subsets of neurons. In another direction, we uncovered a change in phenotype of certain cutaneous sense organs induced by nerve injury and loss of sympathetic innervation. This change appears to involve altered regulation of a membrane receptor molecule by cytokines. The mechanisms underlying such a change are being examined by electrophysiological and cell biological mechanisms originally developed for exploration of normal mechanisms. Thus, our research attempts to define functional, structural and molecular features of peripheral and spinal afferent systems to establish the biological bases of pain and related somatic sensations.
Edward Perl serves on review boards of several journals and has received noteworthy awards and recognition for his scientific work. He was the acting President of the Society for Neuroscience during its founding.