Josef Syka

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..Taken together, the described characteristics of the aging F344 rat auditory system supports the idea that this strain may serve as a suitable model for studying the mechanisms of presbycusis, its prevention and treatment...

..In summary, our results suggest that anesthesia must be considered as an important factor when investigating the processing of complex sounds such as species-specific vocalizations in the auditory cortex...

..8+/-0.18 for white noise, 3.22+/-0.15 for low-frequency noise, P<0.05). A decrease in GDT values during the subsequent months was not observed...

..No such beneficial effect of statins was found in apoE(-/-) mice treated with atorvastatin under the same conditions. Our results suggest that statins could also slow down the age-related deterioration of hearing in man...

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..The results demonstrate a significant deficit in low-frequency hearing and altered otoacoustic emissions in both young and adult F344 rats, suggesting a defect of the inner ear sensory epithelium at the apical part of the cochlea...

..In contrast to MLR amplitudes, ABR amplitudes were suppressed after noise exposure without changing the slope of ABR AIFs. The MLR changes reflect the specific effects of noise exposure on the central auditory system...

..Our findings demonstrate that brief noise exposure in rat pups results in altered behavioral responses to sounds in adulthood, indicating anomalies in intensity coding and loudness perception...

..The observed age-related decline in the levels of GAD65 and 67 may contribute significantly to the deterioration of hearing function that accompanies aging in mammals, including man...

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..The results suggest that such impairments may appear in individuals with normal hearing thresholds, but with a history of noise exposure very early in childhood...

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..The loss of PV-ir neurons in the auditory cortex of Fischer 344 rats with aging may contribute to the substantial deterioration of hearing function in this strain...

..This specific type of strial deterioration suggests that aged F344 rats can serve as an animal model of strial presbycusis...

..This study does not prove the existence of units selectively responding to animal calls, but it provides evidence for the encoding of the spectrotemporal acoustic patterns of vocalizations by IC units...

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..SMI-32-ir neurons apparently form a representative subpopulation of neurons in all parts of the rat central auditory system and may belong to both the inhibitory and excitatory systems, depending on the particular brain region...

..This study demonstrates that the sites of CB and S100 expression in the mouse inner ear during embryonic and early postnatal development do not overlap and signal independent developmental patterns...

..These data provide further evidence for the functional asymmetry of the mammalian brain, which appears in a relatively early phase of evolution...

..These findings may contribute to an explanation of the substantial hearing loss found in old F344 rats...

..The results demonstrate a hemispheric asymmetry of the rat AC in the recognition of FM stimuli and indicate the dominance of the right AC in the discrimination of the direction of frequency modulation...

..The results of spectral analysis suggested that both modes of contralateral stimulation excited similar sensory cochlear elements and induce comparable suppression of both TEOAEs and DPOAEs...

..IC neural activity recovered within several hours, and maximally during 2 days. The results reveal principles of the interaction of cortico-tectal pathways with IC neuronal activity...

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..These results demonstrate a greater susceptibility to noise exposure in rats during the first 5 postnatal weeks...

..The results reveal the complex changes that appear in IC neuronal activity after functional ablation of the ipsilateral auditory cortex...

..The investigation of the principles of the neural coding of species-specific vocalizations offers some keys for understanding the neural mechanisms underlying human speech perception...

..Suppression of the EBA magnitude during contralateral stimulation may be caused either by a reduced spontaneous firing rate or by a decrease in possible synchronised neuronal firing...

..The pronounced deficit in gap detection in some rats after 120 dB SPL noise exposure may signal the presence of a noise-induced tinnitus...

..This suggests that in the MGB the stimulus may desynchronise the spontaneous activity of simultaneously firing units in neuronal pairs...

..The results indicate that electrical stimulation of the IC can activate the efferent system and produce DPOAE changes by similar mechanisms as does acoustical stimulation of the contralateral ear...

..This finding may be related to the abolition of the influence of glutamatergic corticocollicular and commissural pathways...

..The length of dendrites in NADPH-d-positive neurons and their density increased in very old rats. The total number of NADPH-d-positive neurons within the Te 1 and Te 3 fields was 13% lower in the old rats than in the young...

..Minor differences in S100 immunostaining were found postnatally between the cochleas of heterozygous and wild type animals...

..The described program and its results will be used in studying the representation of complex sounds in the central nervous system...

..The results demonstrate that the increase in the high frequency hearing threshold at 16 kHz, which starts at ages over 20 years, is correlated with a decrease in the TEOAE responses at middle frequencies...