What does KOR mean in UNCLASSIFIED

Kappa Opioid Receptors (KOR) are a type of opioid receptor that is mainly found in the central nervous system, including the brain and spinal cord. It belongs to the G-protein coupled receptor family and is activated by natural agonists such as dynorphin and encephalin. KOR has been implicated in several physiological functions including pain, stress response, reward behavior, mood regulation and autonomic function.

Kappa opioid receptors interact with various proteins to form different signaling pathways involving G-Proteins. Activation of KOR will result in the inhibition of adenylyl cyclase activities which leads to reduced cAMP production and consequently decreased intracellular calcium concentration via closing the Calcium channels. This ultimately causes reduction of neurotransmitters release such as glutamate, GABA, dopamine, norepinephrine etc., thereby regulating many physiological functions.

Kappa opioid receptors are predominantly found in areas of the central nervous system such as hippocampus, frontal cortex and midbrain regions as well as other areas like intestine visceral smooth muscle cells and leukocytes.

Activation of kappa opioid receptors can prevent or attenuate pain by decreasing neurotransmitter release from postsynaptic neurons thereby reducing pain signals transmission from peripheral to central nervous system. Furthermore, it can also directly modulate activity of different neurons involved in pain perception through activating inhibitory pathways.

Yes, studies have shown that activation of kappa opioid receptors plays an important role in regulating several behavioral processes like reward behavior, reward anticipation and drug abuse susceptibility. Additionally, KOR also influences emotion regulation by modulating activity of dopaminergic systems associated with fear response.

Yes there are several drug molecules available targeting various physiological functions regulated by KOR. For example Tetrahydropalmatine (THP), JDTic-OH act as potent agonist on KOR while Norbinaltorphimine(norBNI) acts as an antagonist by inhibiting it's activity.

Yes drugs targeting kappa opioid receptors can cause certain unwanted side effects like nausea, vomiting dizziness etc due to inhibition of other unrelated physiological processes regulated by them.

Yes, few studies suggest higher genotypic frequencies in specific human population for both GPR158 gene polymorphism & KOP polymorphism together which might indicate a possible linkage between them.

Studies have found that increased expression levels for GPR158 gene can increase efficacy & potency for drugs acting on KOP receptor although further research needs to be done to confirm it's precise regulatory mechanism.