Role of Substance P in Central Sensory Processing

University Of Florida, Gainesville FL

Investigators

Abstract

Sensory inputs to the brain are modulated by excitatory and inhibitory activity even at the first central synapses where peripheral inputs contact central nerve cells. In the somatosensory system of vertebrates, for touch, heat and pain detection, spinal afferent nerves carrying incoming sensory information terminate in the spinal cord structure called the dorsal horn, where they synapse on central spinal neurons. One of the neurotransmitter compounds, a peptide called Substance P ('SP'), has traditionally been considered to have only excitatory effects in the dorsal horn, though there have been some inferential suggestions of inhibitory effects. This project presents a novel challenge to the traditional view, with direct tests based on recent evidence that SP may increase inhibitory synaptic activity in the dorsal horn. Electrophysiological recordings using the powerful technique of patch-clamping, coupled with new cellular labeling techniques, allow studying cellular and synaptic mechanisms by which SP produces inhibitory activity in the dorsal horn. Results will have a substantial impact in challenging a traditional dogma; the importance extends beyond somatosensory neuroscience to modulation in other senses, and to modeling neuronal circuits. This project also has teaching and interdisciplinary training components for graduate students, including international collaborations with Japan.