TY - JOUR
T1 - Partial mGlu 5 Negative Allosteric Modulators Attenuate Cocaine-Mediated Behaviors and Lack Psychotomimetic-Like Effects
AU - Gould, Robert W.
AU - Amato, Russell J.
AU - Bubser, Michael
AU - Joffe, Max E.
AU - Nedelcovych, Michael T.
AU - Thompson, Analisa D.
AU - Nickols, Hilary H.
AU - Yuh, Johannes P.
AU - Zhan, Xiaoyan
AU - Felts, Andrew S.
AU - Rodriguez, Alice L.
AU - Morrison, Ryan D.
AU - Byers, Frank W.
AU - Rook, Jerri M.
AU - Daniels, John S.
AU - Niswender, Colleen M.
AU - Conn, P. Jeffrey
AU - Emmitte, Kyle A.
AU - Lindsley, Craig W.
AU - Jones, Carrie K.
PY - 2016/3/1
Y1 - 2016/3/1
N2 - Cocaine abuse remains a public health concern for which pharmacotherapies are largely ineffective. Comorbidities between cocaine abuse, depression, and anxiety support the development of novel treatments targeting multiple symptom clusters. Selective negative allosteric modulators (NAMs) targeting the metabotropic glutamate receptor 5 (mGlu 5) subtype are currently in clinical trials for the treatment of multiple neuropsychiatric disorders and have shown promise in preclinical models of substance abuse. However, complete blockade or inverse agonist activity by some full mGlu 5 NAM chemotypes demonstrated adverse effects, including psychosis in humans and psychotomimetic-like effects in animals, suggesting a narrow therapeutic window. Development of partial mGlu 5 NAMs, characterized by their submaximal but saturable levels of blockade, may represent a novel approach to broaden the therapeutic window. To understand potential therapeutic vs adverse effects in preclinical behavioral assays, we examined the partial mGlu 5 NAMs, M-5MPEP and Br-5MPEPy, in comparison with the full mGlu 5 NAM MTEP across models of addiction and psychotomimetic-like activity. M-5MPEP, Br-5MPEPy, and MTEP dose-dependently decreased cocaine self-Administration and attenuated the discriminative stimulus effects of cocaine. M-5MPEP and Br-5MPEPy also demonstrated antidepressant-and anxiolytic-like activity. Dose-dependent effects of partial and full mGlu 5 NAMs in these assays corresponded with increasing in vivo mGlu 5 occupancy, demonstrating an orderly occupancy-To-efficacy relationship. PCP-induced hyperlocomotion was potentiated by MTEP, but not by M-5MPEP and Br-5MPEPy. Further, MTEP, but not M-5MPEP, potentiated the discriminative-stimulus effects of PCP. The present data suggest that partial mGlu 5 NAM activity is sufficient to produce therapeutic effects similar to full mGlu 5 NAMs, but with a broader therapeutic index.
AB - Cocaine abuse remains a public health concern for which pharmacotherapies are largely ineffective. Comorbidities between cocaine abuse, depression, and anxiety support the development of novel treatments targeting multiple symptom clusters. Selective negative allosteric modulators (NAMs) targeting the metabotropic glutamate receptor 5 (mGlu 5) subtype are currently in clinical trials for the treatment of multiple neuropsychiatric disorders and have shown promise in preclinical models of substance abuse. However, complete blockade or inverse agonist activity by some full mGlu 5 NAM chemotypes demonstrated adverse effects, including psychosis in humans and psychotomimetic-like effects in animals, suggesting a narrow therapeutic window. Development of partial mGlu 5 NAMs, characterized by their submaximal but saturable levels of blockade, may represent a novel approach to broaden the therapeutic window. To understand potential therapeutic vs adverse effects in preclinical behavioral assays, we examined the partial mGlu 5 NAMs, M-5MPEP and Br-5MPEPy, in comparison with the full mGlu 5 NAM MTEP across models of addiction and psychotomimetic-like activity. M-5MPEP, Br-5MPEPy, and MTEP dose-dependently decreased cocaine self-Administration and attenuated the discriminative stimulus effects of cocaine. M-5MPEP and Br-5MPEPy also demonstrated antidepressant-and anxiolytic-like activity. Dose-dependent effects of partial and full mGlu 5 NAMs in these assays corresponded with increasing in vivo mGlu 5 occupancy, demonstrating an orderly occupancy-To-efficacy relationship. PCP-induced hyperlocomotion was potentiated by MTEP, but not by M-5MPEP and Br-5MPEPy. Further, MTEP, but not M-5MPEP, potentiated the discriminative-stimulus effects of PCP. The present data suggest that partial mGlu 5 NAM activity is sufficient to produce therapeutic effects similar to full mGlu 5 NAMs, but with a broader therapeutic index.
UR - http://www.scopus.com/inward/record.url?scp=84957594483&partnerID=8YFLogxK
U2 - 10.1038/npp.2015.265
DO - 10.1038/npp.2015.265
M3 - Article
C2 - 26315507
AN - SCOPUS:84957594483
VL - 41
SP - 1166
EP - 1178
JO - Neuropsychopharmacology
JF - Neuropsychopharmacology
SN - 0893-133X
IS - 4
ER -