Doctor Thomas Insel points out that many cognitive disorders have a relatively early onset, and the challenge is to find out the relevant genetic, cellular, and neural correlates.

In my institute at NIMH, we’ve been very interested in sort of scoping out the next 5 years and where we think the most important developments will need to be, and clearly we’re in this revolutionary period in genomics so there will be a lot of activity there. Clearly there is a need to understand the link between the candidate genes that are coming up and the biology of those genes. As we step back and look at the place we are at now and the place we want to be, the thing that has jumped up at us most of all is that most mental disorders start very early in life. That way they are a little different than most neurological disorders that come much, much later in life and most chronic medical illnesses that come on late in life. But schizophrenia, autism, even mood disorders and most anxiety disorders start early. 50% of people who are adults with those illnesses will talk about onset by age 14, at least 50% of those with mood and anxiety disorders which are the prototypic adult mental illnesses, 50% of those have onset by age 14. So these are really early onset. What we’ve begun to understand is that we really know very little about the interactions of genes and environment in brain development; yes there are these very important transition times, there are points that are probably so-called 'sensitive periods' for experience, whether it’s the acquisition of language, the acquisition of social skills, the acquisition of basic motor skills and certainly we’ve known for a long time about the acquisition of vision and auditory information and how they get encoded. What we have yet to do is for these much more complex, for instance social information processing kinds of functions, we haven’t been able to really pin down what are those critical periods and most importantly how are the behavioral changes, that is these behavioral transitions, how are they associated with changes in brain systems and changes in cellular properties within those systems and changes in patterns of gene expression within those cells? That’s where we’re going. It’s doable; we can do this certainly within mice and probably within flies and probably using zebra fish for some properties, not for language but for some things that we’re interested in. But this is going to be the challenge of the next few years, because one of the things we’re likely to learn is that there are these very narrow windows when the right gene has to be turned on in the right place to get a long-term pattern that you need in terms of function. There’s a whole book to be written about this, and this is a place that I think we’re just beginning to get a handle. So much of what we’ve been thinking about in terms of development has been either behavioral development or neural development and we haven’t made that bridge; we haven’t made it in the right way. Much of our neurodevelopmental research, that is neural biology, has been at a very early stage; early stages of differentiation, early stages of migration, a little bit about how circuits form and how the brain gets sculpted. Most of the behavioral development research has been, particularly in humans, at a very late stage. It’s looking at such things as the development of language or the development of visual processing. What we need to do now is to bring these together and to begin to understand, in both humans and non human animals, how do these behavioral changes, these behavioral transitions map onto molecular cellular systems changes in the brain which is supporting them?

neurodevelopment, early, onset, disorders, critical periods, brain development, behavioral changes, mood disorders, neurological disorders, thomas, insel