Abstract

The sensation of pain alerts us to real or impending injury and triggers appropriate protective responses. Unfortunately, pain often outlives its usefulness as a warning system and instead becomes chronic and debilitating. This transition to a chronic phase involves changes within the spinal cord and brain, but there is also remarkable modulation where pain messages are initiated — at the level of the primary sensory neuron. Efforts to determine how these neurons detect pain-producing stimuli of a thermal, mechanical or chemical nature have revealed new signalling mechanisms and brought us closer to understanding the molecular events that facilitate transitions from acute to persistent pain.

1. Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California 94143, USA
2. Departments of Anatomy and Physiology and W. M. Keck Foundation Center for Integrative Neuroscience, University of California San Francisco, San Francisco, California 94143, USA

Correspondence to: David Julius¹ e-mail: Email: julius@socrates.ucsf.edu