OT: Autism

[Guest guest]

2009 Aug;2(4):205-19.

Decreased GABAA receptors and benzodiazepine binding sites in the anterior

cingulate cortex in autism.

Oblak A, Gibbs TT, Blatt GJ.

Boston University School of Medicine, Anatomy and Neurobiology, Boston,

Massachusetts 02118, USA. aoblak@...

Erratum in:

Autism Res. 2009 Aug;2(4):237.

The anterior cingulate cortex (ACC; BA 24) via its extensive limbic and high

order association cortical connectivity to prefrontal cortex is a key part of an

important circuitry participating in executive function, affect, and

socio-emotional behavior. Multiple lines of evidence, including genetic and

imaging studies, suggest that the ACC and gamma-amino-butyric acid (GABA) system

may be affected in autism. The benzodiazepine binding site on the GABA(A)

receptor complex is an important target for pharmacotherapy and has important

clinical implications. The present multiple-concentration ligand-binding study

utilized (3)H-muscimol and (3)H-flunitrazepam to determine the number (B(max)),

binding affinity (K(d)), and distribution of GABA(A) receptors and

benzodiazepine binding sites, respectively, in the ACC in adult autistic and

control cases. Compared to controls, the autistic group had significant

decreases in the mean density of GABA(A) receptors in the supragranular (46.8%)

and infragranular (20.2%) layers of the ACC and in the density of benzodiazepine

binding sites in the supragranular (28.9%) and infragranular (16.4%) lamina

[corrected]. These findings suggest that in the autistic group this

downregulation of both benzodiazepine sites and GABA(A) receptors in the ACC may

be the result of increased GABA innervation and/or release disturbing the

delicate excitation/inhibition balance of principal neurons as well as their

output to key limbic cortical targets. Such disturbances likely underlie the

core alterations in socio-emotional behaviors in autism.

PMID: 19650112 [PubMed - indexed for MEDLINE]

A Powerful Identity, a Vanishing Diagnosis

http://www.nytimes.com/2009/11/03/health/03asperger.html?_r=3 & adxnnl=1 & adxnnlx=1\

257620445-pNzGOwH5beqwQgo41bSfEQ