Age-related changes of NADPH-diaphorase-positive neurons in the rat inferior colliculus and auditory cortex

2007 ◽  
Vol 70 (12) ◽  
pp. 1051-1059 ◽  
Author(s):  
Daniel Sánchez-Zuriaga ◽  
Nuria Martí-Gutiérrez ◽  
Maria Ángeles Pérez De La Cruz ◽  
Maria Rosa Peris-Sanchis
Keyword(s):  
Auditory Cortex ◽  
Inferior Colliculus ◽  
Nadph Diaphorase ◽  
Age Related ◽  
Age Related Changes

scholarly journals Recovery of functional and structural age-related changes in the rat primary auditory cortex with operant training

2010 ◽  
Vol 107 (31) ◽  
pp. 13900-13905 ◽  
Author(s):  
E. de Villers-Sidani ◽  
L. Alzghoul ◽  
X. Zhou ◽  
K. L. Simpson ◽  
R. C. S. Lin ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
Primary Auditory Cortex ◽  
Age Related ◽  
Age Related Changes ◽  
Operant Training

Sensitivity to binaural intensity and phase difference cues in kitten inferior colliculus

1990 ◽  
Vol 64 (2) ◽  
pp. 582-597 ◽  
Author(s):  
B. J. Blatchley ◽  
J. F. Brugge
Keyword(s):  
Auditory Cortex ◽  
Inferior Colliculus ◽  
Phase Difference ◽  
Central Nucleus ◽  
Intensity Difference ◽  
Monotonic Functions ◽  
Age Related ◽  
Highly Correlated ◽  
Intensity Functions ◽  
Almost All

1. Responses of single neurons to monaural or binaural CF tones delivered through a closed and calibrated sound delivery system were studied in the central nucleus of the inferior colliculus (ICC) in ketamine and barbiturate-anesthetized kittens 4-105 days old. 2. Neurons from young kittens had elevated thresholds, some greater than 100 dB in the youngest kittens tested. Average thresholds in the ICC matched those previously measured in the auditory nerve (AN), cochlear nuclei (CN), and auditory cortex (CTX), suggesting that the drop in threshold as a function of age is primarily determined by development at the periphery. 3. Minimal first-spike latencies were relatively long in the youngest kittens, approaching adult values by the end of the third postnatal week. Latencies were distributed between values previously determined for the CN and auditory cortex and can be attributed to the centripetal development of the auditory system. 4. The range of frequencies that were effective in exciting ICC neurons was restricted in young kittens. Neurons having characteristic frequencies (CFs) greater than 7 kHz were not recorded before postnatal day 10. CF distribution matched that obtained in previous experiments from AN, CN, and CTX, reflecting the development of the cochlea. 5. Both monotonic and nonomonotonic spike count-versus-intensity functions were found in the youngest kittens. There was a tendency for monotonic functions from the youngest kittens to be steeper than those from older kittens. No age-related changes in the shapes of non-monotonic functions were found. 6. Sensitivity to interaural intensity difference (IID), tested by holding the intensity to the excitatory ear at a suprathreshold level and increasing the intensity of the stimulus to the inhibitory ear, was exhibited as early as 8 days after birth. The majority of the cells exhibiting sensitivity to IID (89.5%) were classified as EI cells, and almost all IID sensitive cells had CFs between 3 and 25 kHz. Within our sample the shapes of IID functions, as well as the operating range of the IID functions, closely resembled those obtained from the adult cat. Thresholds of excitation and of inhibition were highly correlated, suggesting that the ipsilateral and contralateral inputs to the ICC develop as a matched set. 7. Sensitivity to interaural phase difference (IPD), tested either by shifting the onset phase of a CF tone to one ear relative to the other or by presenting tones of slightly different frequency to the two ears, was present as early as 12 days after birth.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Cortical Responses to the Amplitude Envelopes of Sounds Change with Age

2020 ◽  
Author(s):  
Vanessa C. Irsik ◽  
Ala Almanaseer ◽  
Ingrid S. Johnsrude ◽  
Björn Herrmann
Keyword(s):  
Older Adults ◽  
Auditory Cortex ◽  
Cortical Excitability ◽  
Neural Synchronization ◽  
Speech In Noise ◽  
Age Related ◽  
Cortical Responses ◽  
Sound Features ◽  
Experience Difficulty ◽  
Age Related Changes

AbstractMany older listeners have difficulty understanding speech in noise, when cues to speech-sound identity are less redundant. The amplitude envelope of speech fluctuates dramatically over time, and features such as the rate of amplitude change at onsets (attack) and offsets (decay) signal critical information about the identity of speech sounds. Aging is also thought to be accompanied by increases in cortical excitability, which may differentially alter sensitivity to envelope dynamics. Here, we recorded electroencephalography in younger and older human adults (of both sexes) to investigate how aging affects neural synchronization to 4-Hz amplitude-modulated noises with different envelope shapes (ramped: slow attack & sharp decay; damped: sharp attack & slow decay). We observed that subcortical responses did not differ between age groups, whereas older compared to younger adults exhibited larger cortical responses to sound onsets, consistent with an increase in auditory cortical excitability. Older adults showed increased neural synchronization when the envelope shape was damped compared to ramped, whereas younger participants showed the opposite pattern. Furthermore, the response shape of synchronized neural activity was more sinusoidal in younger individuals, whereas synchronized activity in older adults was less sinusoidal and more peaked. The current results suggest that age-related changes in the excitability of auditory cortex alter responses to envelope dynamics, and this may be part of the reason why older adults experience difficulty understanding speech in noise.Significance StatementMany adults above age 50 report difficulty understanding speech when there is background noise, which can trigger social withdrawal and negative psychosocial health outcomes. The difficulty may be related to age-related changes in how the brain processes temporal sound features. We tested younger and older people on their sensitivity to different envelope shapes, using EEG. Our results demonstrate that aging is associated with heightened sensitivity to sounds with a sharp attack and gradual decay, and sharper neural responses that deviate from the sinusoidal features of the stimulus, perhaps reflecting increased excitability in the aged auditory cortex. Altered responses to temporal sound features may be part of the reason why older adults often experience difficulty understanding speech in social situations.

Quantitative age-related changes in NADPH-diaphorase-positive neurons in the ventral lateral geniculate nucleus

2003 ◽  
Vol 46 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Alicia Villena ◽  
Florentina Dı́az ◽  
Lourdes Vidal ◽  
Mercedes Moreno ◽  
Ignacio Pérez de Vargas
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Nadph Diaphorase ◽  
Lateral Geniculate ◽  
Age Related ◽  
Age Related Changes

scholarly journals A Neural Signature of Regularity in Sound is Reduced in Older Adults

2021 ◽  
Author(s):  
Björn Herrmann ◽  
Burkhard Maess ◽  
Ingrid S. Johnsrude
Keyword(s):  
Older Adults ◽  
Auditory Cortex ◽  
Older Individuals ◽  
Sound Perception ◽  
Younger Adults ◽  
Sound Processing ◽  
Age Related ◽  
Increased Sensitivity ◽  
Neural Signature ◽  
Age Related Changes

AbstractSensitivity to repetitions in sound amplitude and frequency is crucial for sound perception. As with other aspects of sound processing, sensitivity to such patterns may change with age, and may help explain some age-related changes in hearing such as segregating speech from background sound. We recorded magnetoencephalography to characterize differences in the processing of sound patterns between younger and older adults. We presented tone sequences that either contained a pattern (made of a repeated set of tones) or did not contain a pattern. We show that auditory cortex in older, compared to younger, adults is hyperresponsive to sound onsets, but that sustained neural activity in auditory cortex, indexing the processing of a sound pattern, is reduced. Hence, the sensitivity of neural populations in auditory cortex fundamentally differs between younger and older individuals, overresponding to sound onsets, while underresponding to patterns in sounds. This may help to explain some age-related changes in hearing such as increased sensitivity to distracting sounds and difficulties tracking speech in the presence of other sound.

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