Discovery may lead to new treatment for Rett Syndrome

Researchers at Oregon Health & Science University have discovered that a molecule critical to the development and plasticity of nerve cells – brain-derived neurotrophic factor (BDNF) — is severely lacking in brainstem neurons in mutations leading to Rett syndrome, a neurological developmental disorder. The finding has implications for the treatment of neurological disorders, including Rett syndrome that affects one in 10,000 baby girls.

New mechanistic insights into adaptive learning

The brain is a fantastically complex and mysterious device, too large and with too many internal connections to be entirely programmable genetically. Its internal connectivity must therefore self-organize, based on the one hand on genetically regulated biases and on experience and learning on the other. The brain can change its internal connectivity based, for example, on correlations between the inputs it receives and the consequences of actions associated with those inputs, in a phenomenon we generally call associative learning. There are, in our daily life, numerous examples of this type of learning; its consequence is that a smell or a tune on the radio can trigger memories from the past, which lay dormant for some time.

Researchers identify mechanism behind associative memory by exploring insect brains

A key feature of human and animal brains is that they are adaptive; they are able to change their structure and function based on input from the environment and on the potential associations, or consequences, of that input. For example, if a person puts his hand in a fire and gets burned, he learns to avoid flames; the simple sight of a flame has acquired a predictive value, which in this case, is repulsive. To learn more about such neural adaptability, researchers at the California Institute of Technology (Caltech) have explored the brains of insects and identified a mechanism by which the connections in their brain change to form new and specific memories of smells.

In the brain, an earlier sign of autism

In their first year of life, babies who will go on to develop autism already show different brain responses when someone looks at or away from them. Although the researchers are careful to say that the study, reported online on January 26 in the Cell Press journal Current Biology, is only a first step toward earlier diagnosis, the findings do suggest that direct brain measures might help to predict the future development of autism symptoms in infants as young as six months.