title: Early continuous white noise exposure alters auditory spatial sensitivity and expression of GAD65 and GABAA receptor subunits in rat auditory cortex.
abstract: Sensory experiences have important roles in the functional development of the mammalian auditory cortex. Here, we show how early continuous noise rearing influences spatial sensitivity in the rat primary auditory cortex (A1) and its underlying mechanisms. By rearing infant rat pups under conditions of continuous, moderate level white noise, we found that noise rearing markedly attenuated the spatial sensitivity of A1 neurons. Compared with rats reared under normal conditions, spike counts of A1 neurons were more poorly modulated by changes in stimulus location, and their preferred locations were distributed over a larger area. We further show that early continuous noise rearing induced significant decreases in glutamic acid decarboxylase 65 and gamma-aminobutyric acid (GABA)(A) receptor alpha1 subunit expression, and an increase in GABA(A) receptor alpha3 expression, which indicates a returned to the juvenile form of GABA(A) receptor, with no effect on the expression of N-methyl-D-aspartate receptors. These observations indicate that noise rearing has powerful adverse effects on the maturation of cortical GABAergic inhibition, which might be responsible for the reduced spatial sensitivity.
authors.affiliation: School of Life Science, Institute of Cognitive Neuroscience, Shanghai Key Laboratory of Functional Magnetic Resonance Imaging, East China Normal University, Shanghai, China.
authors.forename: Jinghong
authors.initials: J
authors.lastname: Xu
authors.forename: Liping
authors.initials: L
authors.lastname: Yu
authors.forename: Rui
authors.initials: R
authors.lastname: Cai
authors.forename: Jiping
authors.initials: J
authors.lastname: Zhang
authors.forename: Xinde
authors.initials: X
authors.lastname: Sun
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000200:Action Potentials / Q000502:physiology; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001303:Auditory Cortex / Q000166:cytology / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005968:Glutamate Decarboxylase / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000502:physiology; D009622:Noise; D021122:Protein Subunits / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013028:Space Perception / Q000502:physiology*
chemical_list: C120997:NR2A NMDA receptor; C121001:NR2B NMDA receptor; D021122:Protein Subunits; D011963:Receptors, GABA-A; D016194:Receptors, N-Methyl-D-Aspartate; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2