Effect of acute noise trauma on the gene expression profile of the hippocampus

Abstract

Background This study aimed to investigate the changes in the expression of hippocampal genes upon acute noise exposure. Methods Three-week-old Sprague–Dawley rats were assigned to control (n = 15) and noise (n = 15) groups. White noise (2–20 kHz, 115 dB sound pressure level [SPL]) was delivered for 4 h per day for 3 days to the noise group. All rats were sacrificed on the last day of noise exposure, and gene expression in the hippocampus was analyzed using a microarray. Pathway analyses were conducted for genes that showed differential expression ≥ 1.5-fold and P ≤ 0.05 compared to the control group. The genes included in the putative pathways were measured using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Results Thirty-eight upregulated genes and 81 downregulated genes were identified. The pathway analyses revealed that upregulated genes were involved in the cellular responses to external stimuli and immune system pathways. qRT-PCR confirmed the upregulation of the involved genes. The downregulated genes were involved in neuronal systems and synapse-related pathways, and qRT-PCR confirmed the downregulation of the involved genes. Conclusions Acute noise exposure upregulated the expression of immune-related genes and downregulated the expression of neurotransmission-related genes in the hippocampus.

MicroRNA Dysregulation in the Hippocampus of Rats with Noise‐Induced Hearing Loss

“…Our previous microarray study showed that acute noise exposure alters hippocampal gene expression [4]. Another study on an Alzheimer's disease (AD) model has reported that hearing loss induces cognitive deficits and reduced synapse in the hippocampus [5].…”