Age-related hearing loss is manifested primarily by a decreased sensitivity to faint sounds, that is, by elevation of the hearing thresholds. Nevertheless, aging also affects the ability of the auditory system to process temporal parameters of the sound stimulus. To explore the precision and reliability of auditory temporal processing during aging, responses to several types of sound stimuli were recorded from neurons of the auditory cortex (AC) of young and aged anaesthetized Fischer 344 rats. In response to broad-band noise bursts, the aged rats exhibited larger response magnitudes, a higher proportion of monotonic units, and also a larger variability of response magnitudes, suggesting a lower stability of the rate code. Of primary interest were the responses to temporally structured stimuli (amplitude-modulated (AM) noise, frequency-modulated (FM) tones, and click trains) recorded separately in the right and left AC. Significant differences of temporal processing were already found between the neuronal responses in the left and right AC in the young animals: for the click trains, the left hemisphere exhibited a greater responsiveness to higher repetition rates, lower vector strength values, and a lower similarity of responses. The two hemispheres were also affected differently by aging. In the right hemisphere, neurons in the aged animals displayed worse synchronization with the AM noise and clicks, but better synchronization with the FM tone. In the left hemisphere, neuronal synchronization with the stimulus modulation improved at a higher age for all three stimuli. The results show that the ability of the aging auditory system to process temporal parameters of the stimulus strongly depends on the stimulus type and on laterality. Furthermore, the commonly reported age-related decline in the temporal processing ability cannot be regarded as general as, at least at the neuronal level in the AC, objective measures of the temporal representation often exhibit age-related improvement instead of deterioration.

• MeSH
• akustická stimulace MeSH
• krysa rodu rattus MeSH
• potkani inbrední F344 MeSH
• reprodukovatelnost výsledků MeSH
• sluchové korové centrum * MeSH
• vnímání času * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Previous experiments have acknowledged that inappropriate or missing auditory inputs during the critical period of development cause permanent changes of the structure and function of the auditory system (Bures et al., 2017). We explore in this study how developmental noise exposure influences the coding of temporally structured stimuli in the neurons of the primary auditory cortex (AC) in Long Evans rats. The animals were exposed on postnatal day 14 (P14) for 12 minutes to a loud (125 dB SPL) broad-band noise. The responses to an amplitude-modulated (AM) noise, frequency-modulated (FM) tones, and click trains, were recorded from the right AC of rats of two age groups: young-adult (ca. 6 months old) and adult (ca. 2 years old), both in the exposed animals and in control unexposed rats. The neonatal exposure resulted in a higher synchronization ability (phase-locking) of the AC neurons for all three stimuli; furthermore, the similarity of neuronal response patterns to repetitive stimulation was higher in the exposed rats. On the other hand, the exposed animals showed a steeper decline of modulation-transfer functions towards higher modulation frequencies/repetition rates. Differences between the two age groups were also apparent; in general, aging had qualitatively the same effect as the developmental exposure. The current results demonstrate that brief noise exposure during the maturation of the auditory system influences both the temporal and the rate coding of periodically modulated sounds in the AC of rats; the changes are permanent and observable up to late adulthood.

• MeSH
• akustická stimulace MeSH
• hluk škodlivé účinky   MeSH
• krysa rodu rattus MeSH
• potkani Long-Evans MeSH
• sluchová percepce MeSH
• sluchové korové centrum * MeSH
• vnímání času MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Presbycusis, as the deterioration of hearing ability occurring with aging, can be manifested not only in a shift of hearing thresholds, but also in a deterioration of the temporal processing of acoustical signals, which may in elderly people result in degraded speech comprehension. In this study we assessed the age-related changes in the temporal processing of acoustical signals in the auditory system of pigmented rats (Long Evans strain). The temporal resolution was investigated in young adult (3-4 months) and old (30-34 months) rats by behavioral and electrophysiological methods: the rats' ability to detect and discriminate gaps in a continuous noise was examined behaviorally, and the amplitude-rate function was assessed for the middle latency response (MLR) to clicks. A worsening of the temporal resolution with aging was observed in the results of all tests. The values of the gap detection threshold (GDT) and the gap duration difference limen (GDDL) in old rats increased about two-fold in comparison with young adult rats. The MLR to a click train in old rats exhibited a significantly faster reduction in amplitude with an increasing stimulation rate in comparison with young adult rats. None of the age-related changes in the parameters characterizing temporal resolution (GDT, GDDL and MLR to a click train) correlated with the degree of the age-related hearing loss. However, the age-related changes in MLR amplitude-rate function correlated with the age-related changes in GDDL, but not with the changes in GDT. The behavioral and electrophysiological data clearly show that aging in rats is accompanied with a pronounced deficit in the temporal processing of acoustical signals that is associated with the deteriorated function of the central auditory system.

• MeSH
• akustická stimulace MeSH
• diskriminační učení MeSH
• krysa rodu rattus MeSH
• potkani Long-Evans MeSH
• presbyakuze patofyziologie   MeSH
• sluchové evokované potenciály MeSH
• sluchový práh fyziologie   MeSH
• stárnutí fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

PURPOSE: Previous studies have shown that levels for 50% speech intelligibility in quiet and in noise differ for different languages. Here, we aimed to find out whether these differences may relate to different auditory processing of temporal sound features in different languages, and to determine the influence of tinnitus on speech comprehension in different languages. METHODS: We measured speech intelligibility under various conditions (words in quiet, sentences in babble noise, interrupted sentences) along with tone detection thresholds in quiet [PTA] and in noise [PTAnoise], gap detection thresholds [GDT], and detection thresholds for frequency modulation [FMT], and compared them between Czech and Swiss subjects matched in mean age and PTA. RESULTS: The Swiss subjects exhibited higher speech reception thresholds in quiet, higher threshold speech-to-noise ratio, and shallower slope of performance-intensity function for the words in quiet. Importantly, the intelligibility of temporally gated speech was similar in the Czech and Swiss subjects. The PTAnoise, GDT, and FMT were similar in the two groups. The Czech subjects exhibited correlations of the speech tests with GDT and FMT, which was not the case in the Swiss group. Qualitatively, the results of comparisons between the Swiss and Czech populations were not influenced by presence of subjective tinnitus. CONCLUSION: The results support the notion of language-specific differences in speech comprehension which persists also in tinnitus subjects, and indicates different associations with the elementary measures of auditory temporal processing.

• MeSH
• jazyk (prostředek komunikace) MeSH
• lidé MeSH
• percepce řeči * MeSH
• percepční maskování MeSH
• sluchová percepce MeSH
• sluchový práh MeSH
• srozumitelnost řeči MeSH
• tinnitus * MeSH
• vnímání času * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Švýcarsko MeSH

25 lety pacient s chronickými sluchovými halucinacemi byl přijat do Psychiatrického centra Praha. Příznaky se objevily před 1,5 rokem a neodpovídaly pozitivně na farmakoterapii antipsychotiky. Neuropsychologické vyšetření zachytilo postižení verbálních exekutivních funkcí. MRI vyšetření odhalilo 52x65x62 mm velkou supratentoriální temporální arachnoidální cystu vlevo a neexpanzivní arachnoideální cystu kontralaterálně temporálně o velikosti 15xl5x 30 mm. Cysta vlevo se chovala expansivně k temporálnímu kortexu, který byl oploštělý, Neurochirurgicky byl proveden návrt cysty s následnou její dekompresi. V krátkém časovém odstupu po operaci nedošlo k žádnému zlepšení sluchových halucinací ani verbálně exekutivních funkcí.

A 25 year old male with chronic auditory hallucinations was admitted to the Prague Psychiatric Center. The onset of symptoms wa s 1.5 year prior to the current hospitalization; the patient was resistant to antipsychotic drug treatment. Neuropsychological as sessment revealed marked rigidity in verbal skills. MRI scan showed a left-sided supratentorial temporal arachnoid cyst with the size of 52x65x62 mm and a right-sided non-expansive temporal arachnoid cyst with the size of 15x15x30 mm. The expansive left cyst oppressed the tem- poral cortex that has flattened. Subsequent neurosurgical operation (using a drill hole) has led to pressure decompression in t he cyst. However, no early post surgical improvement of auditory hallucinations or verbal skills could be detected.

• MeSH
• antipsychotika terapeutické užití   MeSH
• cysty centrálního nervového systému diagnóza   etiologie   chirurgie   MeSH
• dospělí MeSH
• finanční podpora výzkumu jako téma MeSH
• halucinace diagnóza   etiologie   terapie   MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   využití   MeSH
• neurochirurgické výkony metody   využití   MeSH
• poruchy sluchové percepce diagnóza   etiologie   terapie   MeSH
• psychologické testy normy   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• kazuistiky MeSH

The left auditory cortex (AC) in humans is involved in the processing of the temporal parameters of acoustical signals, specifically in speech perception, whereas the right AC plays the dominant role in pitch and melody perception. The hemispheric lateralization of acoustical signal processing in non-human mammals is less explored. The present study examined the ability of rats to detect or discriminate a series of gaps in continuous noise under conditions of unilateral or bilateral reversible inactivation of the AC. The results showed that muscimol-induced reversible inactivation of the left AC suppresses the ability of rats to discriminate between acoustical stimuli of different temporal parameters (duration or repetition rate), whereas inactivation of the right AC results in no change or only a mild decrease in discrimination ability. Hemispheric asymmetry was observed only in the case of gap discrimination tasks, but not in a gap detection task. Our findings demonstrate that, similarly as in humans, the left AC in the rat plays the dominant role in temporal discrimination. These data provide further evidence for the functional asymmetry of the mammalian brain, which appears in a relatively early phase of evolution.

• MeSH
• akustická stimulace metody   MeSH
• centrální poruchy sluchu chemicky indukované   komplikace   MeSH
• diskriminace (psychologie) fyziologie   MeSH
• elektrický šok škodlivé účinky   MeSH
• funkční lateralita fyziologie   MeSH
• GABA agonisté škodlivé účinky   MeSH
• klasické podmiňování fyziologie   MeSH
• krysa rodu rattus MeSH
• modely nemocí na zvířatech MeSH
• muscimol škodlivé účinky   MeSH
• poruchy sluchové percepce etiologie   MeSH
• sluchové korové centrum účinky léků   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• sluchové korové centrum fyziologie   MeSH
• Publikační typ
• kongresy MeSH

• Konspekt
• Lékařské vědy. Lékařství
• NLK Obory
• otorinolaryngologie
• fyziologie

AUT00063 and AUT00202 are novel pharmaceutical modulators of the Kv3 subfamily of voltage-gated K+ channels. Kv3.1 channels, which control fast firing of many central auditory neurons, have been shown to decline with age and this may contribute to age-related deficits in central auditory processing. In the present study, the effects of the two novel compounds that specifically modulate Kv3 channels on auditory temporal processing were examined in aged (19-25-month-old) and young-adult (3-5 month-old) Fischer 344 rats (F344) using a behavioral gap-prepulse inhibition (gap-PPI) paradigm. The acoustic startle response (ASR) and its inhibition induced by a gap in noise were measured before and after drug administration. Hearing thresholds in tested rats were evaluated by the auditory brainstem response (ABR). Aged F344 rats had significantly higher ABR thresholds, lower amplitudes of ASR, and weaker gap-PPI compared with young-adult rats. No influence of AUT00063 and AUT00202 administration was observed on ABR hearing thresholds in rats of both age groups. AUT00063 and AUT00202 had suppressive effect on ASR of F344 rats that was more pronounced with AUT00063. The degree of suppression depended on the dose and age of the rats. Both compounds significantly improved the gap-PPI performance in gap detection tests in aged rats. These results indicate that AUT00063 and AUT00202 may influence intrinsic firing properties of neurons in the central auditory system of aged animals and have the potential to treat aged-related hearing disorders.

• MeSH
• akustická stimulace MeSH
• draslíkové kanály Shaw MeSH
• krysa rodu rattus MeSH
• potkani inbrední F344 MeSH
• prepulsní inhibice MeSH
• sluchová percepce * MeSH
• sluchové kmenové evokované potenciály * MeSH
• sluchový práh MeSH
• úleková reakce MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cílem sdělení je hledání vztahu mezi poruchou řečové percepce u dětí s vývojovýmiporuchami řeči a poruchou časového zpracování akustických podnětů. Byly sledovány BAEP (kme-nové sluchové potenciály) u 42 dětí s vývojovou dysfázií nebo dysarthrií. U dětí s dysarthrií bylynalezeny stranové rozdíly v latencích V. vlny a potvrzena hypotéza o postižení centrálního motone-uronu v podkorových oblastech. LAEP (korové sluchové potenciály) byly sledovány u 32 dětí s vý-vojovou dysfázií, u níž je typická porucha rozumění řeči. Byly zjištěny statisticky významné rozdílyv hodnotách latence vlny P3 (prodloužení) po verbální stimulaci oproti stimulaci tonální a kontrolev záznamech z levé hemisféry. Tyto výsledky podporují představu o poruše časového zpracovánířečového signálu u dětí s vývojovou dysfázií.

The author analyses the role of auditory perception of children suffering from developmental speech disorders (developmental language disorder - DLD) by using auditory evoked potentials to clarify the relationship between disorder of speech comprehension and temporal processing. Diagnostic categories of interest are DLD, more commonly known in our country as developmental dysphasia and dysarthria. Children with country as developmental dysphasia have maximum difficulties in processing of the speech signal - auditory decoding deficit. This deficit in phonological processing has been suggested to be one of the basic underlying problems. Children with developmental dysarthria have specific articulation disorders without a cognitive deficit. Results: BAEP (brain stem auditory evoked potential) - a statistically significant difference between the values of latencies of wave V was found in children with dysarthria, in comparison of right a and left stimulated ears. In these children we assume a lesion in the subcortical region while in children with developmental dysphasia we suppose a more central localization of the time delay, i.e. in the cortical region. LAEP (long latency auditory evoked potential) were studied in children with developmental dysphasia. When comparing the results after tonal and verbal stimulation at the left side a statistically significant difference was found: the latencies of wave P3 to verbal stimuli were longer on the left side compared to tonal stimuli and to control. Latency differences may be related to a common timing deficit in developmental speech disorders. These results confirm disorders of temporal processing.

• MeSH
• audiologie MeSH
• dítě MeSH
• finanční podpora výzkumu jako téma MeSH
• lidé MeSH
• mozková kůra fyziologie   MeSH
• mozkový kmen fyziologie   MeSH
• percepce řeči MeSH
• poruchy řeči diagnóza   etiologie   MeSH
• předškolní dítě MeSH
• sluchové evokované potenciály MeSH
• vývoj řeči MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• srovnávací studie MeSH

We performed a systematic study to check whether neurons in the area TE (the anterior part of inferotemporal cortex) in rhesus monkey, regarded as the last stage of the ventral visual pathway, could be modulated by auditory stimuli. Two fixating rhesus monkeys were presented with visual, auditory or combined audiovisual stimuli while neuronal responses were recorded. We have found that the visually sensitive neurons are also modulated by audiovisual stimuli. This modulation is manifested as the change of response rate. Our results have shown also that the visual neurons were responsive to the sole auditory stimuli. Therefore, the concept of inferotemporal cortex unimodality in information processing should be re-evaluated.

• MeSH
• akustická stimulace metody   využití   MeSH
• experimenty na zvířatech MeSH
• financování organizované MeSH
• Haplorrhini MeSH
• implantované elektrody využití   MeSH
• Macaca mulatta MeSH
• metaanalýza jako téma MeSH
• mozková kůra anatomie a histologie   fyziologie   MeSH
• neurony fyziologie   MeSH
• sluchové evokované potenciály fyziologie   MeSH
• sluchové korové centrum anatomie a histologie   fyziologie   MeSH
• statistika jako téma MeSH
• světelná stimulace metody   MeSH