Salvinorin B, kappa-opioid DREADD (KORD) agonist

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

The Kappa Opioid Receptor also known as KOR or kappa receptors is a type of opioid receptor that plays an important role in the nervous system. It is a protein with an approximate mass of 43 kDa. This receptor mainly expresses in the human brain especially in regions involved in pain and stress responses such as the hypothalamus and thalamus. Kappa receptors are involved in modulating neurotransmitter release and can affect synaptic transmission.

Biological function summary

Kappa opioid receptors mediate pain perception mood regulation and stress response. They form part of a larger receptor family the G-protein coupled receptors (GPCRs) which are critical in cellular signaling. Activation of these receptors can produce analgesic effects differing from other opioid receptors due to their unique mechanism of action. Kappa receptors interact with endogenous ligands called dynorphins which are peptide neurotransmitters involved in natural pain relief processes.

Pathways

Kappa opioid receptors are integral to the dopaminergic and serotonergic pathways. In the dopaminergic pathway kappa receptors reduce dopamine release influencing the reward system and potentially affecting addiction behaviors. In the serotonergic pathway they modulate serotonin levels connecting to mood and anxiety regulation. These pathways also involve proteins like the mu-opioid receptor and delta-opioid receptor which along with kappa receptors form a complex regulatory network.

Kappa opioid receptors have been linked to depression and drug addiction. In depression dysfunctional kappa receptor activity may disrupt mood regulation contributing to depressive symptoms. The associated protein dynorphin plays a role in this condition by interacting with kappa receptors. In drug addiction these receptors influence the brain's reward circuits impacting addiction severity through altered dopamine signaling. Understanding kappa receptors can offer insights into new therapeutic approaches for these conditions.