And the race goes on

Linguists love critical period studies. It never ceases to fascinate them that what appears to come so efforlessly to children is so effortful to adults. Most famously, generativist like to use this to make an argument for some grammar module in the brain some universal grammar built in.

Our colleague Namhee Lee has done really elegant work to examine neural changes over time that seem to show that there may be general brain changes that contribute to changing language learning abilities. Most recently he's been looking at developmental changes in dopamine and opiod production. Here's another developmental change that will be of interest for critical period people:

Harvard Medical School researchers report in the August 17 Science Express that adult mice lacking the immune system protein paired-immunoglobulin like receptor-B (PirB) had brains that retained the plasticity of much younger brains, suggesting that PirB inhibits such plasticity.

From Biosingularity

Basically, it looks like this protien PirB is a player in how brains change in plasticity, which is learning, over time. Our group hasn't spent much time with protiens, but it might be time soon.

More quotes below

Several years ago, Shatz and colleagues made the surprising discovery that MHC Class I genes are turned on in neurons by neuronal activity and in fact are required for normal synaptic plasticity. In the immune system, MHC Class I proteins teach immune cells which cells to attack. They do this by interacting with a large number of receptors found on the surface of immune cells. Syken, Shatz and colleagues wondered whether such receptors might also be expressed in neurons and involved in MHC Class I-mediated synaptic plasticity.

Using a method called in situ hybridization, they found that the MHC Class I receptor PirB is expressed widely throughout the brain and at all ages. To see how PirB was functioning, they generated a mouse deficient in PirB. At first sight, the mutant’s brain appeared normal. To get a better sense of how PirB might be affecting plasticity, they decided to focus on the visual cortex.



“Our discovery underscores further the fascinating and common molecular parallels between the nervous system and the immune system, where PirB was first studied. The discovery of a neuronal receptor for MHC Class I opens up a completely new avenue for thinking about broader roles for this family of molecules beyond the immune system,” he said.