gesunheitpfleges.org



New study: Immune molecules can regulate synaptic connections in brain

January 08, 2016

In this and another recently published study, McAllister's group found that MHC type I molecules are present on young brain cells during early postnatal development. To test their function, they studied mice lacking MHC type I on the surface of neurons, as well as isolated neurons from mice and rats with altered levels of MHC type I. They found that when the density of these molecules on the surface of a brain cell goes up, the number of connections, or synapses, it has with neighboring brain cells goes down. The reverse was also true: decreased MHC expression increased synaptic connections.

"The effect on synapse density was mediated through MHC type I proteins," McAllister said.

"But these immune proteins don't just regulate synapse density, they also determine the balance of excitation and inhibition on young neurons -- a property critical for information processing and plasticity in young brains."

Expression of MHCI on neurons was itself regulated by neural activity, the team found, and MHCI mediated the ability of neural activity to alter synaptic connections.

About 10 years ago, other researchers discovered that MHC type I is involved in elimination of connections during a critical period of late postnatal brain development.

"We have now found that there is another role for MHC type I in establishing connections during early postnatal development of the brain," McAllister said.

Source: University of California - Davis