Memory impairment induced by military noise-induced hidden hearing loss in mice:role of hippocampal NR2B downregulation
FU Yang
QIN Jian
JIANG Yihong
ZHU Jing
ZHANG Min
CHANG Tong
WANG Jiale
ZHANG Zhiwei
CHEN Tao
WANG Xiaocheng
Abstract：Objective To investigate whether noise-induced hidden hearing loss(NIHHL)leads to memory dysfunction in mice and to analyze the expression changes of memory-related proteins N-methyl-D-aspartate receptor 2A(NR2A)and N-methyl-D-aspartate receptor 2B(NR2B)in the hippocampal region of NIHHL mice.Methods A total of 12 male C57 mice with normal hearing were randomly divided into 2 groups,with 6 mice in each group.The NIHHL group was exposed to 110 dB noise for 2 hours,while the CON group received no noise exposure.Auditory brainstem response(ABR)testing and behavioral experiments were conducted before noise exposure,and at 1 d and 1 month after exposure.One month after noise exposure,hippocampal tissues and bilateral cochlear tissues were collected from both groups.Western blotting was used to detect the expression of NR2A and NR2B proteins in the hippocampal region,and immunofluorescence staining was employed to assess the number of cochlear ribbon synapses.Results Compared with the CON group,the NIHHL group showed increased hearing thresholds(P<0.05),decreased ABR waveⅠamplitude(P<0.01),and prolonged ABR wave Ⅰ latency(P<0.05)at 1 d after noise exposure.At 1 month after noise exposure,the hearing thresholds and ABR wave Ⅰ latency in the NIHHL group recovered to normal levels(P>0.05),but the ABR wave Ⅰ amplitude remained decreased(P<0.05),and the number of cochlear inner hair cell ribbon synapses was reduced(P<0.05).Behavioral tests revealed prolonged latency to first reach the original platform position in the Morris water maze(P<0.01),shortened swimming distance in the target quadrant(P<0.05);decreased spontaneous alternation rate in the Y maze(P<0.01);and reduced cognitive index in the novel object recognition test(P<0.01).Additionally,the expression of NR2B protein in the hippocampal region was downregulated(P<0.05).Conclusion The downregulation of NR2B protein expression in the hippocampal region of NIHHL mice may be associated with the occurrence and development of memory dysfunction.
Keywords：military aviation noisehidden hearing lossmemory impairmentauditory brainstem responsecochlear ribbon synapseshippocampusNR2ANR2B
Publication Date：2026-01-31
Online Publishing Date：2026-08-26(First online date of this platform, not the publication date of the document)
Pages：8( 109-116 )