Conclusions: We suggest that age-induced changes of serotonin, N-methyl-d-aspartate receptor (NMDAR), and glutamate decarboxylase (GAD) expression in rats are dependent on the specific location in the central auditory system (CAS).
Objectives: Despite the importance of understanding changes in neurotransmitters during presbycusis, only a few studies have assessed age-associated changes in neurotransmitter at each level of the CAS. We therefore evaluated effects of aging on neurotransmission in the CAS of rats.
Methods: The concentrations of serotonin, NMDAR, and GAD were assayed immunohistochemically in the cochlear nucleus (CN), superior olivary nucleus (SON), inferior colliculus (IC), medial geniculate body (MGB), and auditory cortex (AC) of Sprague-Dawley rats, aged 2 weeks (n = 20) or 24 months (n = 20).
Results: The total number of neuronal cell bodies of the CAS did not differ significantly at each level between young and aged rats (p > 0.05). Serotonin expression was increased with age in the IC and MGB, but decreased in the CN, SON, and AC (p < 0.05). NMDAR was significantly higher in the CN, MGB, and AC of aged compared with young rats, but was significantly decreased over time in the SOC and IC (p < 0.05). GAD67 was increased with age in the MGB and AC and decreased in the CN and SON (p < 0.05), but was not changed in the IC.
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http://dx.doi.org/10.3109/00016489.2011.622785 | DOI Listing |
J Speech Lang Hear Res
January 2025
Department of Special Education, Central China Normal University, Wuhan.
Purpose: This cross-sectional study explored how the speechreading ability of adults with hearing impairment (HI) in China would affect their perception of the four Mandarin Chinese lexical tones: high (Tone 1), rising (Tone 2), falling-rising (Tone 3), and falling (Tone 4). We predicted that higher speechreading ability would result in better tone performance and that accuracy would vary among individual tones.
Method: A total of 136 young adults with HI (ages 18-25 years) in China participated in the study and completed Chinese speechreading and tone awareness tests.
Front Neuroanat
January 2025
Sudha Gopalakrishnan Brain Centre, Indian Institute of Technology Madras, Chennai, India.
The inferior colliculus (IC) is an important midbrain station of the auditory pathway, as well as an important hub of multisensory integration. The adult mammalian IC can be subdivided into three nuclei, with distinct cyto- and myeloarchitectonical profiles and distinct calcium binding proteins expression patterns. Despite several studies about its structural and functional development, the knowledge about the human fetal IC is rather limited.
View Article and Find Full Text PDFFront Mol Neurosci
January 2025
Department of Otorhinolaryngology, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, China.
Auditory neuropathy spectrum disorder (ANSD) is an auditory dysfunction disorder characterized by impaired speech comprehension. Its etiology is complex and can be broadly categorized into genetic and non-genetic factors. mutation is identified as a causative factor in ANSD.
View Article and Find Full Text PDFAnn Intern Med
January 2025
959 Medical Operations Squadron, U.S. Air Force, Department of Neurology, Brooke Army Medical Center, San Antonio, Texas (T.K.).
Description: In July 2024, the U.S. Department of Veterans Affairs (VA) and U.
View Article and Find Full Text PDFFront Neurol
January 2025
Department of Basic Medical Sciences, School of Medicine, Xiamen University, Xiamen, China.
Walking ability is essential for human survival and health. Its basic rhythm is mainly generated by the central pattern generator of the spinal cord. The rhythmic stimulation of music to the auditory center affects the cerebral cortex and other higher nerve centers, and acts on the central pattern generator.
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