A point-of-care (POC) device to measure mouse glucose and lipid profiles is an important unmet need for cost-effective, immediate decision making in research. We compared metabolic analyte profiles obtained using a human clinical POC device with those from a veterinary laboratory chemical analyzer (LCA). Unfasted terminal blood samples were obtained by cardiac puncture from C57Bl/6J mice used in a diet-induced obesity model of type 2 diabetes mellitus; age-matched C57Bl/6J controls; a transgenic mouse model of Alzheimer's disease on a C57BL/6J background (16 wk old); and aged C57BL/6J mice (24 to 60 wk old).
View Article and Find Full Text PDFThe auditory steady-state evoked response (ASSR) is a scalp-recorded potential elicited by modulated sounds or repetitive transient sounds presented at a high rate. The binaural interaction component (BIC) of the ASSR equals the difference between the response to binaural stimuli and the sum of the responses to a monaural stimulus presented to the left ear and the right ear. This study examined the effect of the interaural time (ITD) and level (ILD) difference on the BIC of the 80 Hz ASSR.
View Article and Find Full Text PDFThe amplitude of the 2f1-f2 distortion product otoacoustic emission (DPOAE) can be suppressed by presenting contralateral acoustic stimulation. To test the hypothesis that DPOAE contralateral suppression is influenced by the primary frequency in DPgrams, DPgrams were recorded at resolutions of 1, 8, and 17 pts/octave, in the absence and presence of contralateral broadband noise (BBN). Participants were 20 normal-hearing human adults.
View Article and Find Full Text PDFDecrement detection is a commonly used psychophysical technique in which a subject is required to detect partially filled gaps in an ongoing sound. The paradigm provides information regarding both temporal resolution and intensity discrimination. The purpose of this project was to determine if an evoked-potential paradigm using decrements in an ongoing noise approximates psychophysical data.
View Article and Find Full Text PDFAge-related hearing loss (ARHL or presbyacusis) is an increasingly common form of sensorineural hearing loss (SNHL) as a result of changing demographics, and the auditory brainstem response (ABR) is a common experimental and clinical tool in audiology and neurology. Some of the changes that occur in the aging auditory system may significantly influence the interpretation of the ABR in comparison to the ABRs of younger adults. The approach of this review will be to integrate physiological and histopathological data from human and animal studies to provide a better understanding of the array of age-related changes in the ABR and to determine how age-related changes in the auditory system may influence how the ABR should be interpreted in presbyacusis.
View Article and Find Full Text PDFThe effect of age on susceptibility to noise-induced hearing loss (NIHL), the effect of gender on the interaction of age-related hearing loss (ARHL) and NIHL, and the relative contributions of ARHL and NIHL to total hearing loss are poorly understood. The issues are difficult to resolve empirically in human subjects because of lack of control over extrinsic variables and for ethical reasons. Accordingly, these issues were examined in a well-studied animal model of both ARHL and NIHL, the Mongolian gerbil.
View Article and Find Full Text PDFAge-dependent hearing loss has been well documented in gerbils exceeding 2 years of age using physiological methods (e.g. [Mills et al.
View Article and Find Full Text PDFThe frequency-modulation following response (FMFR) is a steady-state evoked response which may be a neural correlate of frequency discrimination. Aged subjects with normal hearing have abnormal frequency discrimination for low carrier frequencies and thus it might be predicted that aged individuals would have reduced FMFR amplitudes compared to young subjects. In this study, FMFR amplitudes were measured for frequency-modulated sinusoids with a carrier frequency of 0.
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