Fig. 1. Local inhibitory circuits are modified in chronic pain.
(A) Under normal conditions, pyramidal neurons (PN) are appropriately modulated by mainly somatostatin (SOM) and parvalbumin (PV)-expressing inhibitory neurons. Vasoactive intestinal polypeptide (VIP)-expressing inhibitory neurons primarily inhibit other subtypes of inhibitory neuron, and preferentially suppresses SOM activity. SOM and PV neurons contribute to tuft dendritic and perisomatic inhibition of pyramidal neurons, respectively. (B) Tissue or nerve injury alters local inhibitory circuits towards hyperactivity of pyramidal neurons, leading to chronic pain. Enhanced VIP activity reduces SOM and PV activities and ultimately enhances PN hyperactivity.
© Korean J Physiol Pharmacol
