Receptors

Receptors are specialized proteins on the surface or inside cells that detect chemical or physical signals and trigger specific cellular responses.

In pain medicine, receptors are central to how pain is perceived and modulated. Examples include opioid receptors (which reduce pain when activated by endorphins or medications), NMDA receptors (involved in central sensitization and hyperalgesia), and TRPV1 receptors (which respond to heat and chemical irritants like capsaicin).

Changes in receptor activity or sensitivity often underlie chronic pain. For instance, upregulation of NMDA receptors can amplify pain signals, while reduced opioid receptor function may decrease the body’s ability to regulate pain naturally. Many modern treatments — from drugs to interventional techniques — aim to either block, activate or modulate receptor activity.

In the context of pulsed radiofrequency (PRF), studies suggest that electromagnetic fields may influence receptor expression and intracellular signaling, helping to “reset” overactive pain pathways. This receptor-level modulation is thought to be one of the mechanisms behind PRF’s effectiveness in chronic pain.