Noise exposure alters MMP9 and brevican expression in the rat primary auditory cortex

• Published in: BMC neuroscience Vol. 21; no. 1; p. 16
• Main Authors: Park, Sung-Su, Lee, Da-Hye, Lee, So Min, Lee, Chang Ho, Kim, So Young
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 25.04.2020; BioMed Central; BMC
• Subjects: Aggrecan; Antibodies; Auditory cortex; Brevican; Carbon dioxide; Cortex (auditory); GABA; Gelatinase B; Gene expression; Glutamate; Glutamate decarboxylase; Glutamatergic transmission; Hearing Loss; Hearing protection; Immunofluorescence; Inferior colliculus; Matrix metalloproteinase 9; Medical research; Noise; Noise control; Noise-induced; Parvalbumin; Perineuronal nets; Polymerase chain reaction; Protein expression; Proteins; Reverse transcription; γ-Aminobutyric acid; St Louis Missouri; United Kingdom > UK; United States > US; Matrix metalloproteinase 9; Noise-induced; Brevican; Auditory cortex; Hearing Loss
• ISSN: 1471-2202; 1471-2202
• DOI: 10.1186/s12868-020-00567-3

This study aimed to investigate the changes in molecules related to perineuronal nets (PNNs) and synaptic transporters in the primary auditory cortices of rats with noise-induced hearing loss. Female Sprague-Dawley rats at postnatal day 7 were divided into the noise and control groups. Four hours of 115 dB SPL white noise was delivered for 10 days to the noise group. Thirty days after noise exposure, the primary auditory cortex and the inferior colliculus were harvested. The expression levels of vesicular glutamatergic transporter (VGLUT)1, VGLUT2, vesicular GABA transporter (VGAT), glutamate decarboxylase (GAD)67, brevican, aggrecan, MMP9, and MMP14 were evaluated using real-time reverse transcription polymerase chain reaction or western blot. An immunofluorescence assay was conducted to assess parvalbumin (PV), Wisteria floribunda agglutinin (WFA), and brevican. The immune-positive cells were counted in the primary auditory cortex. The expression level of VGLUT1 in the primary auditory cortex was decreased in the noise group. The expression level of VGLUT2 in the inferior colliculus was elevated in the noise group. The expression levels of brevican and PV + WFA in the primary auditory cortex were decreased in the noise group. The expression level of MMP9 in the primary auditory cortex was increased in the noise group. Noise-induced hearing loss during the precritical period impacted PNN expression in the primary auditory cortex. Increased MMP9 expression may have contributed to the decrease in brevican expression. These changes were accompanied by the attenuation of glutamatergic synaptic transporters.