PMID- 28336100 OWN - NLM STAT- MEDLINE DCOM- 20180227 LR - 20181031 IS - 1873-507X (Electronic) IS - 0031-9384 (Linking) VI - 175 DP - 2017 Jun 1 TI - In vivo evaluation of the hippocampal glutamate, GABA and the BDNF levels associated with spatial memory performance in a rodent model of neuropathic pain. PG - 97-103 LID - S0031-9384(17)30074-4 [pii] LID - 10.1016/j.physbeh.2017.03.025 [doi] AB - BACKGROUND: Patients with chronic pain usually suffer from learning and memory impairment which may significantly decrease their quality of life. Despite laboratory and clinical studies, the mechanism underlying this memory impairment remains elusive. We evaluated the effect of chronic pain on the glutamate and GABA levels and BDNF expression in the CA1 region of hippocampus as a possible explanation for memory impairment related to neuropathic pain. METHODS: In this respect, 30 male rats were randomly allocated to 3 groups as control, sham and neuropathic. Neuropathic pain was induced by a chronic constriction injury of the sciatic nerve (CCI) and mechanical allodynia and the spatial memory was assessed using the Von Frey filaments and Morris water maze respectively. To determine the potential mechanisms, the in vivo extracellular levels of glutamate and gamma-aminobutyric acid (GABA) were measured by microdialysis and the brain-derived neurotrophic factor (BDNF) expression was determined by using western blots technique in the hippocampus on days 14 and 21 post-CCI. RESULTS: We showed that CCI impaired spatial learning and memory in Morris water maze (MWM) task. BDNF expression level and glutamate concentration significantly decreased in rats with chronic constriction injury of the sciatic nerve (P<0.001, F=7.3, F=23.23). In addition, GABA increased in hippocampal CA1 region (P<0.001, F=39.2) when the pain threshold was minimum. Nevertheless, these changes reversed while pain was relieved spontaneously. CONCLUSION: Chronic pain induced by constriction of the sciatic nerve impairs the spatial learning and memory function in rats. This effect exerts through the increase in GABA concentration and decrease in the glutamate and BDNF levels in the CA1 region of the hippocampus. CI - Copyright (c) 2017 Elsevier Inc. All rights reserved. FAU - Saffarpour, S AU - Saffarpour S AD - Neuroscience Research Center of Kerman, University of Medical Science, Kerman, Iran. FAU - Shaabani, M AU - Shaabani M AD - Neuroscience Research Center of Kerman, University of Medical Science, Kerman, Iran. FAU - Naghdi, N AU - Naghdi N AD - Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran. FAU - Farahmandfar, M AU - Farahmandfar M AD - Department of Neuroscience, School of Advanced Medical Technologies, Tehran University of Medical Sciences, Tehran, Iran. FAU - Janzadeh, A AU - Janzadeh A AD - Physiology Research Center, Department of Physiology, Iran University of Medical Sciences, Tehran, Iran. FAU - Nasirinezhad, F AU - Nasirinezhad F AD - Physiology Research Center, Department of Physiology, Iran University of Medical Sciences, Tehran, Iran. Electronic address: nasirinezhad.f@iums.ac.ir. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20170320 PL - United States TA - Physiol Behav JT - Physiology & behavior JID - 0151504 RN - 0 (Brain-Derived Neurotrophic Factor) RN - 3KX376GY7L (Glutamic Acid) RN - 56-12-2 (gamma-Aminobutyric Acid) SB - IM MH - Analysis of Variance MH - Animals MH - Brain-Derived Neurotrophic Factor/*metabolism MH - Chromatography, High Pressure Liquid MH - Disease Models, Animal MH - Glutamic Acid/*metabolism MH - Hippocampus/*metabolism MH - Hyperalgesia/physiopathology MH - Male MH - Maze Learning MH - Memory Disorders/*etiology MH - Microdialysis MH - Neuralgia/*complications/*pathology MH - Pain Threshold/physiology MH - Rats MH - Reaction Time/physiology MH - gamma-Aminobutyric Acid/*metabolism OTO - NOTNLM OT - Brain-derived neurotrophic factor (BDNF) OT - Chronic constriction injury (CCI) OT - Glutamate OT - Hippocampus OT - Morris water maze task OT - Neuropathic pain OT - Spatial memory OT - gamma-Aminobutyric acid (GABA) EDAT- 2017/03/25 06:00 MHDA- 2018/02/28 06:00 CRDT- 2017/03/25 06:00 PHST- 2016/12/30 00:00 [received] PHST- 2017/03/18 00:00 [revised] PHST- 2017/03/18 00:00 [accepted] PHST- 2017/03/25 06:00 [pubmed] PHST- 2018/02/28 06:00 [medline] PHST- 2017/03/25 06:00 [entrez] AID - S0031-9384(17)30074-4 [pii] AID - 10.1016/j.physbeh.2017.03.025 [doi] PST - ppublish SO - Physiol Behav. 2017 Jun 1;175:97-103. doi: 10.1016/j.physbeh.2017.03.025. Epub 2017 Mar 20.