Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004352 (autism)
 32,579 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of the present study was to investigate the relations between late auditory evoked potentials (AEPs) recorded at temporal sites (the N1c wave or Tb) and verbal and non-verbal abilities in children with autism. The study was performed in 26 mentally retarded children with autism (AUT) aged 4-8 years (mean age +/- S.E.M. = 71 +/- 2 months; mean verbal and non-verbal developmental quotient +/- S.E.M. = 36 +/- 4 and 48 +/- 3). The stimuli used were 750 Hz tone bursts of 200 ms duration delivered binaurally at different intensity levels (50, 60, 70, 80 dB SPL) with 3-5 s interstimulus intervals. Temporal AEPs were first compared to those of a group of 16 normal children (NOR) in the same age range (mean age +/- S.E.M. = 69 +/- 3 months). We then focused on the AUT group and considered relations between temporal AEPs and the severity of disorders of verbal and non-verbal communication assessed using a behavior rating scale. AEPs recorded on left and right temporal sites were of smaller amplitude in the AUT group than in the NOR group. Increasing intensity-related amplitude was observed on both sides in NOR and only on the right side in AUT. The lack of intensity effect on the left side resulted in a particular pattern of asymmetry at the highest level of intensity (80 dB SPL) with greater N1c amplitude on the right than on the left side (the reverse was found in the NOR group). Electro-clinical correlations indicated that the greater the amplitude of the right temporal N1c responses, the higher the verbal and non-verbal communication abilities. This suggests a developmental reorganization of left-right hemisphere functions in autism, with preferential activation of the right hemisphere for functions usually allocated to the left hemisphere, particularly those involving the secondary auditory areas situated on the lateral surface of the superior temporal gyrus where the N1c/Tb wave is generated.
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PMID:Cortical auditory processing and communication in children with autism: electrophysiological/behavioral relations. 1462 19

Hyperacusis, a marked intolerance to normal environmental sound, is a common symptom in patients with tinnitus, Williams syndrome, autism, and other neurologic diseases. It has been suggested that an imbalance of excitation and inhibition in the central auditory system (CAS) may play an important role in hyperacusis. Recent studies found that noise exposure, one of the most common causes of hearing loss and tinnitus, can increase the auditory cortex (AC) response, presumably by increasing the gain of the AC. However, it is not clear whether the increased cortical response will affect sound sensitivity and induce hyperacusis. In this experiment, we studied the effects of noise exposure (narrow band noise, 12 kHz, 120 dB SPL, 1 hour) on the physiological response of the inferior colliculus (IC) and the AC, and the behavioral sound reaction in conscious Sprague Dawley rats. Noise exposure induced a decrease of sound evoked potential in the IC. However, significant increases of AC response including sound evoked potentials and the spike firing rates of AC neurons were recorded right after the noise exposure. These results suggest that noise exposure induces hyperexcitability of AC presumably by increasing the post-synaptic response of AC neurons. The behavioral consequence of the noise exposure on sound perception was measured by the amplitude of the acoustic startle response before and after noise exposure in a separate group of rats. Although noise exposure caused a moderate hearing loss, the acoustic startle amplitude at the super-threshold level was significantly increased. These results suggest that noise exposure can cause exaggerated the sound reaction which may be related with the enhanced responsiveness of the AC neurons. This phenomenon may be related with noise induced hyperacusis.This article is part of a Special Issue entitled: Tinnitus Neuroscience.
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PMID:Noise exposure enhances auditory cortex responses related to hyperacusis behavior. 2240 30

Investigation of objective and quantitative behavioral phenotypes along with neurobiological endophenotypes might lead to increased knowledge of the mechanisms that underlie autism spectrum disorders (ASD). Here, we investigated the association between locomotor dynamics and characteristics of the acoustic startle response (ASR) and its modulation in ASD (n = 14) and typically developing (TD, n = 13) children. The ASR was recorded in response to acoustic stimuli in increments of 10 dB (65-105 dB SPL). We calculated the average ASR magnitude for each stimulus intensity and peak-ASR latency. Locomotor activity was continuously measured with a watch-type actigraph. We examined statistics of locomotor activity, such as mean activity levels and the skewness of activity. Children with ASD had a significantly greater ASR magnitude in response to a weak acoustic stimulus, which reflects acoustic hyper-reactivity. The skewness of all-day activity was significantly more negative in children with ASD than those with TD. Skewness of daytime activity was also more negative, although only of borderline statistical significance. For all children, the higher mean and more negatively skewed daytime activity, reflecting hyperactivity that was associated with sporadic large daytime "troughs," was significantly correlated with acoustic hyper-reactivity. The more negatively skewed locomotor activity occurring in the daytime was also associated with impaired sensorimotor gating, examined as prepulse inhibition at a prepulse intensity of 70 dB. This comprehensive investigation of locomotor dynamics and the ASR extends our understanding of the neurophysiology that underlies ASD.
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PMID:Acoustic Hyper-Reactivity and Negatively Skewed Locomotor Activity in Children With Autism Spectrum Disorders: An Exploratory Study. 3012 55