Complementary ideas

A Harvard team has mapped one of the strongest, and most difficult to decipher, genetic risk factors for schizophrenia to C4a, a molecule involved in the complement cascade. While the results offer a new therapeutic target for the disease, the underlying mechanism is still up for debate.

The researchers, who published the study last month in Nature, believe the data support a model in which C4a drives excessive synaptic pruning, pushing the normal developmental process of removing the wrong synapses too far, resulting in loss of necessary synapses. Moreover, the team claims the findings could explain why symptoms arise in the teens and twenties, when higher order cortical regions undergo pruning...