Autism spectrum disorders are prevalent neurodevelopmental disorders that involve early postnatal symptoms and regression of developmental milestones within the first few years of life. Healthy brain development, particularly in regions of the cortex involved in sensory and cognitive processing, depends on periods of rapid cellular growth known as critical periods. Connections between neurons, or synapses, are formed and refined during these time-restricted windows in a process known as synaptic plasticity, which is key to the proper functioning of the brain. Mouse models of autism show delays in specific developmental milestones: Synaptic connections remain in an immature state past the normal closure of the critical period, and there is a shift in the window for when synapses can be modified by experience.
Anis Contractor and his colleagues at Northwestern University in Chicago are working to determine the mechanisms that contribute to disrupted synaptic development during the critical period for plasticity in a mouse model of autism. Based on knowledge of normal regulatory processes during this critical period, the researchers hypothesize that disruption of inhibitory neurotransmitter networks in the cortex may underlie the altered brain development seen in autism spectrum disorders.
They plan to use single-cell recording techniques to test whether inhibitory neurotransmitter networks are disrupted in the cortex of the model mice during the critical period. Defining the precise mechanisms that contribute to altered development during the critical period may open new avenues to therapeutic interventions to prevent or reverse some of these developmental disruptions.