Determining the impact of neocortex size changes on information processing : implications for neurodevelopmental disorders

Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2021
Thesis identifier
  • T15908
Person Identifier (Local)
  • 201764485
Qualification Level
Qualification Name
Department, School or Faculty
  • Development of the cerebral cortex is highly regulated by genetically programmed sequential events. Alterations in this process by genetic or non-genetic factors can lead to over- or underproduction of cortical neurons and abnormal connectivity, resulting in neurodevelopmental disorders, such as autism spectrum disorder (ASD). Although ASD patients often exhibit atypical sensory processing, the relationship between abnormal cortical size and sensory processing is still unclear. Here we hypothesise that abnormal cortical expansion during development leads to atypical sensory processing. To test this hypothesis, we utilized a recently established mouse model, in which the number of superficial cortical excitatory neurons is increased pharmacologically during embryonic development. This mouse model is also known to exhibit macrocephaly and autism-like phenotypes. In this project, we assessed their auditory perception behaviourally and evaluated neuronal population activity in the auditory cortex and medial geniculate nucleus through high-density in vivo electrophysiological recording. Our results indicate that the overproduction of superficial cortical excitatory neurons negatively affects auditory processing. Treated mice exhibited hyposensitivity to near-threshold auditory stimuli during behavioural auditory detection assessment. Further, their cortical neurons showed lower spontaneous and auditory evoked activity as well as delayed peak response latency. We also observed atypical cortical functional connectivity. Overall, our study suggests that abnormal cortical expansion during development results in atypical auditory processing, and provides further insights into the neural basis of perceptual deficits in neurodevelopmental disorders such as ASD.
Advisor / supervisor
  • Sakata, Suzo
Resource Type