February 14, 2011

The Brain Learns from Mistakes

(Ivanhoe Newswire) -- The brain makes mistakes and then corrects them, according to a new study.

A research group, led by Dr. Peter Scheiffele at the Biozentrum of the University of Basel, was able to document the brain's process of establishing a neuronal network that does not always prove precise or error-free.

In the developing brain, countless nerve connections are made, which turn out to be inappropriate, and as a result, must eventually be removed. Using a genetic mouse model, the researchers employed advanced microscopy techniques in the developing cerebellum -- the area of the brain required for fine movement control. The team discovered that a protein traditionally associated with bone development is responsible for correcting errors while neurons connect to their correct partners in the cerebellum.

The cerebellum has very precise connectivity that allows the brain to use sensory information (input) and convert it into an exact motor response (output). Two cell types in the cerebellum are known as Purkinje cells and granule cells. Mossy fibers are a group of inputs in the cerebellum that make connections only with granule cells.

However, the research team was able to demonstrate that the mossy fiber inputs also often connect with Purkinje neurons during early brain development. These "incorrect" connections are then eliminated within a week. Bone morphogenetic protein 4 (BMP4) helps correct these initial errors.

"If inappropriate connections between neurons are not subsequently eliminated, this can lead to substantial disturbances in the brain. Autism could also be linked to this form of failure to correct errors," Scheiffele was quoted as saying.

Dr. Scheiffele's future research will focus on the implications these findings may have on disorders like autism, schizophrenia and epilepsy.

SOURCE: PLoS Biology, Feb. 2011