of individuals with ASD also have sensory hypersensitivity, which can cause extreme reactions to certain sounds, textures, or lights. This can lead to avoidance of certain situations or environments and can significantly impact daily functioning.
The research team found that a specific receptor in the brain, called the mGluR5 receptor, is overactive in individuals with ASD. This overactivity leads to an increase in signaling between neurons, which ultimately results in sensory hypersensitivity. By identifying this specific mechanism, the researchers hope to develop targeted treatments that can alleviate sensory hypersensitivity in individuals with ASD, ultimately improving their quality of life. The findings of this study were published in the journal Neuron.
Autism patients often experience abnormal sensory hypersensitivity, which significantly impacts their daily lives. This hypersensitivity results in extreme or reduced reactions to common sensory stimuli like sound, light, and touch, leading to high levels of stress and isolation. The specific brain region responsible for this sensory dysfunction remains unknown, making it challenging to develop effective treatments.
Researchers at the IBS conducted a study on an ASD mouse model with a mutation in the Grin2b gene, which is responsible for encoding the GluN2B subunit of NMDA receptors. NMDA receptors, a type of glutamate receptor in the brain, have received a lot of attention in recent years.in the realm of autism due to their significant role in synaptic transmission and neural plasticity. It was suggested that the Grin2b gene mutation in mice might lead to ASD-like characteristics such as sensory abnormalities, and that specific brain mechanisms could be influential.
The scientists observed neural activity and functional connectivity in the brains of these mice using activity-dependent markers and functional magnetic resonance imaging (fMRI). They found heightened neuronal activity in the anterior cingulate cortex (ACC) in these mice. The ACC is a higher-order cortical region thatThe anterior cingulate cortex (ACC) has received a lot of attention for its role in cognitive and emotional brain functions, but its connection to sensory abnormalities related to brain disease has been overlooked. It is interesting to note that when the hyperactivity of ACC neurons was suppressed using chemogenetic methods, sensory hypersensitivity was improved. This suggests that ACC hyperactivity plays a crucial role in sensory hypersensitivity seen in individuals with autism. Director KIM Eunjoon remarks, “This new research shows that the anterior cingulate cortex (ACC), which is known for its strong ties to cognitive and social functions, also plays a part in sensory hypersensitivity in autism.”The ACC’s overactivity was linked to increased functional connectivity with other parts of the brain. Both the hyperactivity and hyperconnectivity of the ACC with different brain regions are believed to contribute to sensory hypersensitivity in Grin2b-mutant mice. Director KIM Seong-Gi says, “Previous studies emphasized the importance of peripheral neurons or primary cortical areas in ASD-related sensory hypersensitivity. These studies typically focused on the activity of a single brain region. In contrast, our study examines not only the activity of the ACC but also the widespread hyperconnectivity throughout the brain.”The researchers are investigating the connection between the ACC and different brain regions to gain a better understanding of the brain. They are planning to delve into the specific mechanisms behind the heightened excitatory synaptic activity and increased neuronal connectivity. They believe that the absence of Grin2b expression may disrupt the usual process of weakening and eliminating less active synapses, allowing more active synapses to play a role in refining neural circuits based on activity. Additionally, they are interested in exploring the role of the ACC in other mouse models of ASD.
