Sunday, January 20, 2013
cool new blog by Dr. Manuel Casanova
I'm happy to report that the neuroscientist Dr. Manuel Casanova, who's done research involving minicolumns in the post mortem brains of autistic persons has has recently started a new blog called cortical chauvinism, which should be some interesting stuff about neuroscience, particularly the neuroscience of autism. The good doctor's first entry deals with the problems of extrapolating mice models of autism to humans, since the brains of the two species are so different. Dr. Casanova has found that a unit of the brain called minicolumns-a vertical structure that contains 80 to 100 neurons working together- are more numerous in the postmortem autistic brains that he studied and also have less neurons in them and are narrower than in typical control brains. He also found the insulation of the autistic minicolumns was not as well developed as in typical brains. He has used the analogy of a broken shower curtain which means that certain neurotransmitters such as GABA can get through, abnormally exciting the neurons. Interestingly, he found these in the prefrontal cortex, an area that Eric Courchesne found to be abnormally enlarged and have an abnormal number of neurons in some autistic brains. Also these are part of the mirror neuron system that Dr. Marco Iacoboni has described. He and other researchers have found abnormalities of these type of neurons in the autistic brains on functional MRIs. Courchesne seemed to think that one of the problems of Casanova's research was that all of the postmortem brains were those of adults rather than small children. Since the autistic brain undergoes developmental changes throughout the lifetime, this could limit the minicolumn findings. Of course, there are a dearth of toddlers brains available for postmortem autopsy. I asked Dr.Iacoboni if mirror neurons could exist on minicolumns, i.e. whether or not you could have a minicolumn with 60 to 80 mirror neurons on it. He replied that we didn't know but probably not. So apparently, there are a lot more questions than answers. Though some of the science on this new blog post and future posts that Dr. Casanova may write may be a bit out of my depth, I still find this a really intriguing new blog and I hope Dr. Casanova continues to write posts.