Dysregulation of Reelin and Bcl-2 proteins in autistic cerebellum.
Autistic cerebellums have significantly reduced proteins that guide brain cell development, helping explain motor and attention differences.
01Research in Context
What this study did
Scientists measured two proteins in the cerebellums of adults with autism. They compared the levels to adults without autism.
They used post-mortem brain tissue. The team looked at Reelin and Bcl-2 proteins that help brain cells move and survive.
What they found
Autistic cerebellums had 34-a large share less Reelin protein. They also had 34-a large share less Bcl-2 protein.
These proteins guide brain cell placement during development. Lower levels may explain why autistic cerebellums develop differently.
How this fits with other research
Weiss et al. (2001) found similar protein problems in the hippocampus. Their post-mortem study showed reduced GABA receptors in autism brains. Both studies used the same lab methods on donated brain tissue.
Pan et al. (2021) reviewed 20 years of autism brain research. Their meta-analysis includes these cerebellar protein findings. The review shows autism brains have many structural differences across regions.
Noordenbos et al. (2012) tracked corpus callosum size for two years. They found persistent volume reductions in autistic children. Together these studies show autism involves lasting brain structure changes from proteins to whole regions.
Why it matters
These protein deficits help explain behavioral challenges you see in clients. The cerebellum controls motor planning and attention. When Reelin and Bcl-2 are low, cells may not connect properly. This could contribute to motor delays or attention issues common in autism. While you can't measure these proteins in living clients, knowing they exist validates why autistic brains process information differently. Use this knowledge to advocate for motor skills training and structured learning environments that work with these neurological differences.
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02At a glance
03Original abstract
Autism is a severe neurodevelopmental disorder with potential genetic and environmental causes. Cerebellar pathology including Purkinje cell atrophy has been demonstrated previously. We hypothesized that cell migration and apoptotic mechanisms may account for observed Purkinje cell abnormalities. Reelin is an important secretory glycoprotein responsible for normal layering of the brain. Bcl-2 is a regulatory protein responsible for control of programmed cell death in the brain. Autistic and normal control cerebellar corteces matched for age, sex, and post-mortem interval (PMI) were prepared for SDS-gel electrophoresis and Western blotting using specific anti-Reelin and anti-Bcl-2 antibodies. Quantification of Reelin bands showed 43%, 44%, and 44% reductions in autistic cerebellum (mean optical density +/- SD per 30 microg protein 4.05 +/- 4.0, 1.98 +/- 2.0, 13.88 +/- 11.9 for 410 kDa, 330 kDa, and 180 kDa bands, respectively; N = 5) compared with controls (mean optical density +/- SD per 30 microg protein, 7.1 +/- 1.6, 3.5 +/- 1.0, 24.7 +/- 5.0; N = 8, p < 0.0402 for 180 kDa band). Quantification of Bcl-2 levels showed a 34% to 51% reduction in autistic cerebellum (M +/- SD per 75 microg protein 0.29 +/- 0.08; N = 5) compared with controls (M +/- SD per 75 microg protein 0.59 +/- 0.31; N = 8, p < 0.0451). Measurement of beta-actin (M +/- SD for controls 7.3 +/- 2.9; for autistics 6.77 +/- 0.66) in the same homogenates did not differ significantly between groups. These results demonstrate for the first time that dysregulation of Reelin and Bcl-2 may be responsible for some of the brain structural and behavioral abnormalities observed in autism.
Journal of autism and developmental disorders, 2001 · doi:10.1023/a:1013234708757