Blood vessels in unborn babies could be a pathway for disabilities, says study

BLOOD vessels which protect babies brains during pregnancy could also be a pathway for disabilities such as autism, suggests a study.

The choroid plexus, deep inside the brain, could explain why children born to mothers who fall ill during pregnancy are more likely to suffer from neurological disorders such as autism, say scientists.

Infections during pregnancy, such as the common cold, do not usually cause serious problems, but others, such as urinary tract infections, can.

The tiny organs, which produce cerebrospinal fluid (CSF), are so deep in the brain that it has been “very difficult” to observe them, until now.

Small plexiglass windows had to be fitted into the brains of mice in order to observe the elusive “fronds of tissue”.

Lead author Dr Maria Lehtinen, of Boston Children’s Hospital in the US, said: “There is a correlation between maternal illness during pregnancy and autism, and we wanted to investigate how this is happening.

“It’s a very challenging process to study in the lab.”

The miniature organs are known to be a hotbed of immune system activity, helping regulate a baby’s brain development during pregnancy and forming a protective barrier to stop unwanted cells or molecules in the blood from entering the brain.

Special imaging tools were used on embryonic mice to capture the actions of cells in and around the mysterious brain branches.

A tiny part of the embryos’ skull bone was replaced with a small piece of clear plexiglass to create a “skylight” into the brain.

The unborn rodents’ choroid plexus could then be observed in real-time using live two-photon imaging.

Live two-photon imaging uses near-infrared light to view living tissue up to about one millimetre in thickness. Next, the mothers’ immune system was artificially triggered with cytokine, a molecular messenger.

Immune cells known as macrophages were drawn to the embryos choroid plexus when the mother’s immune system was triggered, the researchers found. Dr Lehtinen said: “We could see macrophages moving and extending little arms as if sampling their environment.”