title: Decreased auditory GABA+ concentrations in presbycusis demonstrated by edited magnetic resonance spectroscopy.
abstract: Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the central auditory system. Altered GABAergic neurotransmission has been found in both the inferior colliculus and the auditory cortex in animal models of presbycusis. Edited magnetic resonance spectroscopy (MRS), using the MEGA-PRESS sequence, is the most widely used technique for detecting GABA in the human brain. However, to date there has been a paucity of studies exploring changes to the GABA concentrations in the auditory region of patients with presbycusis. In this study, sixteen patients with presbycusis (5 males/11 females, mean age 63.1 ± 2.6 years) and twenty healthy controls (6 males/14 females, mean age 62.5 ± 2.3 years) underwent audiological and MRS examinations. Pure tone audiometry from 0.125 to 8 kHz and tympanometry were used to assess the hearing abilities of all subjects. The pure tone average (PTA; the average of hearing thresholds at 0.5, 1, 2 and 4 kHz) was calculated. The MEGA-PRESS sequence was used to measure GABA+ concentrations in 4 × 3 × 3 cm(3) volumes centered on the left and right Heschl's gyri. GABA+ concentrations were significantly lower in the presbycusis group compared to the control group (left auditory regions: p = 0.002, right auditory regions: p = 0.008). Significant negative correlations were observed between PTA and GABA+ concentrations in the presbycusis group (r = -0.57, p = 0.02), while a similar trend was found in the control group (r = -0.40, p = 0.08). These results are consistent with a hypothesis of dysfunctional GABAergic neurotransmission in the central auditory system in presbycusis and suggest a potential treatment target for presbycusis.
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, Jinan, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, Jinan, China.
authors.forename: Guangbin
authors.initials: G
authors.lastname: Wang
authors.affiliation: The Central Hospital of Jinan City, Shandong University, Jinan, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Ma
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, Jinan, China.
authors.forename: Fuxin
authors.initials: F
authors.lastname: Ren
authors.affiliation: College of Electronics and Information Engineering, Sichuan University, Chengdu, China.
authors.forename: Muwei
authors.initials: M
authors.lastname: Li
authors.affiliation: The Central Hospital of Jinan City, Shandong University, Jinan, China.
authors.forename: Yuling
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, Jinan, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Liu
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, Jinan, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, Jinan, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Bai
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, Jinan, China. Electronic address: qpqpoo6262@163.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; FM Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.
authors.forename: Richard A E
authors.initials: RA
authors.lastname: Edden
mesh_terms: D000161:Acoustic Stimulation; D000368:Aged; D001303:Auditory Cortex / Q000378:metabolism* / Q000503:physiopathology; D001307:Auditory Perception / Q000502:physiology*; D005260:Female; D006320:Hearing Tests; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011304:Presbycusis / Q000378:metabolism* / Q000503:physiopathology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D005680:gamma-Aminobutyric Acid