PSYC 304 - Chapter 8.4

Pain

The discomfort normally associated with tissue damage.

Congenital Insensitivity to Pain

The condition of being born without the ability to perceive pain.

Nociceptor

A receptor that responds to stimuli that produce tissue damage or pose the threat of damage.

Free Nerve Ending

An axon that terminates in the skin without any specialized cell associated with it and that detects pain and/or changes in temperature.

Capsaicin

A compound synthesized by various plants to deter predators by mimicking the experience of burning.

Transient Receptor Potential Vanilloid Type 1 (TRPV1)

Also called vanilloid receptor 1; a receptor that binds capsaicin to transmit the burning sensation from chili peppers and normally detects sudden increases in temperature.

Transient Receptor Potential Type M3 (TRPM3)

A receptor, found in some free nerve endings, that opens its channel in response to rising temperatures.

A Delta Fiber

A moderately large, myelinated, and therefore fast-conducting axon, usually transmitting acute pain information.

C fiber

A small, unmyelinated axon that conducts pain information slowly and adapts slowly.

TRPM8

Also called cool-menthol receptor 1 (CMR1); a sensory receptor found in some free nerve endings, that opens an ion channel in response to a mild temperature drop or exposure to menthol.

SCN9A

Also called NAv1.7; a voltage-gated sodium channel used almost exclusively by nociceptors to initiate action potentials.

Anterolateral System

Also called spinothalamic system; a somatosensory system that carries most of the pain and temperature information from the body to the brain.

Glutamate

An amino acid transmitter; the most common excitatory transmitter.

Substance P

A peptide transmitter implicated in pain transmission.

Migraines

Intense headaches, typically perceived from one half of the head, that recur regularly and can be difficult to treat.

Natriuretic Polypeptide B (Nppb)

A peptide neurotransmitter used by neurons reporting itch to the spinal cord.

Neuropathic Pain

Pain caused by damage to the peripheral nerves. It is often difficult to treat.