When a Helpful Brain Signal Gets “Stuck”: A New Clue in the Biology of Autism
Recent research is shedding light on the neurobiological underpinnings of autism, suggesting that a key brain process – the filtering of sensory information – may become “stuck,” leading to the intense focus and sensory sensitivities often observed in individuals with autism spectrum disorder (ASD). Understanding these neurological differences is crucial for moving beyond pathologizing views and embracing neurodiversity, fostering acceptance and appropriate support.
Scientists are increasingly focused on how the brain’s structure and function differ in autism. Studies utilizing neuroimaging techniques have revealed variations in neuronal connections compared to neurotypical brains. Specifically, researchers have identified two primary patterns: heightened local connectivity and diminished global connectivity.
“Hiperconectividad local,” or increased local connectivity, refers to stronger connections between neurons within specific brain areas, particularly those involved in sensory perception and logical thinking. This may explain the intense attention to detail and the ability to deeply focus on topics of interest often seen in autistic individuals. Conversely, “hipoconectividad global,” or decreased global connectivity, describes less efficient connections between distant brain regions, potentially hindering the integration of information from various sources, such as combining facial expressions with tone of voice to interpret emotions.
The research also points to altered sensory processing and amplified perception in many people with autism. The way the brain filters and prioritizes sensory information differs, leading to unique experiences. This is linked to alterations in synaptic development, as many genes associated with autism encode proteins crucial for synapse function.
According to research published in Medicina (Buenos Aires), approximately half of the instructions within our genome are dedicated to brain development. The study highlights that autism involves functional alterations of the cerebral cortex, with structural anomalies in neurodevelopment impacting synaptic function and the pattern of connections within and between cortical columns.
The origins of autism are considered to be a combination of “de novo” mutations – new genetic changes – alongside a predisposition stemming from inherited common variations. The Instituto de Neurociencias Aplicadas notes that these genetic anomalies primarily involve genes that code for synaptic proteins.
Researchers are also exploring the role of cellular models in studying autism. These models, derived from human cells, offer a valuable tool for investigating the underlying mechanisms of the disorder. Further research is ongoing to understand the complex interplay of genetic, environmental and neurological factors contributing to autism spectrum disorder.
