TY - JOUR T1 - Modulation of TARP <em>γ</em>8–Containing AMPA Receptors as a Novel Therapeutic Approach for Chronic Pain JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 345 LP - 363 DO - 10.1124/jpet.118.250126 VL - 369 IS - 3 AU - Kelly L. Knopp AU - Rosa Maria A. Simmons AU - Wenhong Guo AU - Benjamin L. Adams AU - Kevin M. Gardinier AU - Douglas L. Gernert AU - Paul L. Ornstein AU - Warren Porter AU - Jon Reel AU - Chunjin Ding AU - He Wang AU - Yuewei Qian AU - Kevin D. Burris AU - Anne Need AU - Vanessa Barth AU - Steven Swanson AU - John Catlow AU - Jeffrey M. Witkin AU - Ruud Zwart AU - Emanuele Sher AU - Kar-Chan Choong AU - Theron M. Wall AU - Douglas Schober AU - Christian C. Felder AU - Akihiko S. Kato AU - David S. Bredt AU - Eric S. Nisenbaum Y1 - 2019/06/01 UR - http://jpet.aspetjournals.org/content/369/3/345.abstract N2 - Nonselective glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonists are efficacious in chronic pain but have significant tolerability issues, likely arising from the ubiquitous expression of AMPA receptors in the central nervous system (CNS). Recently, LY3130481 has been shown to selectively block AMPA receptors coassembled with the auxiliary protein, transmembrane AMPA receptor regulatory protein (TARP) γ8, which is highly expressed in the hippocampus but also in pain pathways, including anterior cingulate (ACC) and somatosensory cortices and the spinal cord, suggesting that selective blockade of γ8/AMPA receptors may suppress nociceptive signaling with fewer CNS side effects. The potency of LY3130481 on recombinant γ8-containing AMPA receptors was modulated by coexpression with other TARPs; γ2 subunits affected activity more than γ3 subunits. Consistent with these findings, LY3130481 had decreasing potency on receptors from rat hippocampal, cortical, spinal cord, and cerebellar neurons that was replicated in tissue from human brain. LY3130481 partially suppressed, whereas the nonselective AMPA antagonist GYKI53784 completely blocked, AMPA receptor–dependent excitatory postsynaptic potentials in ACC and spinal neurons in vitro. Similarly, LY3130481 attenuated short-term synaptic plasticity in spinal sensory neurons in vivo in response to stimulation of peripheral afferents. LY3130481 also significantly reduced nocifensive behaviors after intraplantar formalin that was correlated with occupancy of CNS γ8-containing AMPA receptors. In addition, LY3130481 dose-dependently attenuated established gait impairment after joint damage and tactile allodynia after spinal nerve ligation, all in the absence of motor side effects. Collectively, these data demonstrate that LY3130481 can suppress excitatory synaptic transmission and plasticity in pain pathways containing γ8/AMPA receptors and significantly reduce nocifensive behaviors, suggesting a novel, effective, and safer therapy for chronic pain conditions. ER -