Induction of a focal freeze lesion to the skullcap of a 1-day-old rat pup leads to the formation of microgyria similar to those identified postmortem in human dyslexics. Rats with microgyria exhibit rapid auditory processing deficits similar to those seen in language-impaired (LI) children, and infants at risk for LI and these effects are particularly marked in juvenile as compared to adult subjects. In the current study, a startle response paradigm was used to investigate gap detection in juvenile and adult rats that received bilateral freezing lesions or sham surgery on postnatal day (P) 1, 3 or 5. Microgyria were confirmed in P1 and 3 lesion rats, but not in the P5 lesion group. We found a significant reduction in brain weight and neocortical volume in P1 and 3 lesioned brains relative to shams. Juvenile (P27-39) behavioral data indicated significant rapid auditory processing deficits in all three lesion groups as compared to sham subjects, while adult (P60+) data revealed a persistent disparity only between P1-lesioned rats and shams. Combined results suggest that generalized pathology affecting neocortical development is responsible for the presence of rapid auditory processing deficits, rather than factors specific to the formation of microgyria per se. Finally, results show that the window for the induction of rapid auditory processing deficits through disruption of neurodevelopment appears to extend beyond the endpoint for cortical neuronal migration, although, the persistent deficits exhibited by P1 lesion subjects suggest a secondary neurodevelopmental window at the time of cortical neuromigration representing a peak period of vulnerability.
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http://dx.doi.org/10.1016/j.brainres.2006.06.022 | DOI Listing |
Biol Psychol
January 2025
Department of Psychology, College of Humanities and Management, Guizhou University of Traditional Chinese Medicine, Guiyang, China.
Audiovisual associative memory and audiovisual integration involve common behavioral processing components and significantly overlap in their neural mechanisms. This suggests that training on audiovisual associative memory may have the potential to improve audiovisual integration. The current study tested this hypothesis by applying a 2 (group: audiovisual training group, unimodal control group) * 2 (time: pretest, posttest) design.
View Article and Find Full Text PDFbioRxiv
January 2025
Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Auditory processing in the cerebral cortex is considered to begin with thalamocortical inputs to layer 4 (L4) of the primary auditory cortex (A1). In this canonical model, A1 L4 inputs initiate a hierarchical cascade, with higher-order cortices receiving pre-processed information for the slower integration of complex sounds. Here, we identify alternative ascending pathways in mice that bypass A1 and directly reach multiple layers of the secondary auditory cortex (A2), indicating parallel activation of these areas alongside sequential information processing.
View Article and Find Full Text PDFBMC Pediatr
January 2025
MD, Pediatrician, Research Professor of Developmental Pediatrics, Pediatric Neurorehabilitation Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Background: Children with physical disabilities (Having this type of disability can be due to any of the reasons such as cerebral palsy, genetic, developmental, neurodevelopment and any other reasons that cause physical disability in the child) need rehabilitation services. Tele-rehabilitation is a practical approach to provide rehabilitation services for children with rapid and continuous access. This approach has been used more recently and overcomes the limitations of conventional rehabilitation, which involves wasting time, traveling distance, and cost.
View Article and Find Full Text PDFJ Neurodev Disord
January 2025
Graduate Neuroscience Program, University of California, Riverside, CA, USA.
Background: Fragile X syndrome (FXS) is a leading known genetic cause of intellectual disability and autism spectrum disorders (ASD)-associated behaviors. A consistent and debilitating phenotype of FXS is auditory hypersensitivity that may lead to delayed language and high anxiety. Consistent with findings in FXS human studies, the mouse model of FXS, the Fmr1 knock out (KO) mouse, shows auditory hypersensitivity and temporal processing deficits.
View Article and Find Full Text PDFJ Neurosci
January 2025
Neuroscience and Cognitive Science Program, University of Maryland, College Park, Maryland, 20742.
Hearing is an active process in which listeners must detect and identify sounds, segregate and discriminate stimulus features, and extract their behavioral relevance. Adaptive changes in sound detection can emerge rapidly, during sudden shifts in acoustic or environmental context, or more slowly as a result of practice. Although we know that context- and learning-dependent changes in the sensitivity of auditory cortical (ACX) neurons support many aspects of perceptual plasticity, the contribution of subcortical auditory regions to this process is less understood.
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