The August edition of the Nature Neuroscience podcast, NeuroPod, arrived online after a summer break with some fascinating discussions on everything from altruism to magic.
Perhaps the most interesting bit is on genomic imprinting – a curious effect where the same gene may be expressed differently depending on whether you inherited it from your mother or your father.
The most widely known examples are the Prader-Willi and Angelman syndromes, both of which are genetic disorders linked to learning disabilities and neurological problems.
Both are caused by a partial deletion of genes from chromosome 15. When this is inherited from the mother, it causes Angelman syndrome, when inherited from the father, it causes Prader-Willi syndrome.
A recent opinion piece published in Nature, written by sociologist Christopher Badcock and biologist Bernard Crespi, argued that genetic imprinting may be key to a much wider range of conditions – including many of the more common psychiatric disorders such as depression or schizophrenia.
We believe that psychiatric illness may be less to do with the genes a mother and father pass down, and more to do with which genes they program for expression. By our hypothesis, a hidden battle of the sexes — where a mother’s egg and a father’s sperm engage in an evolutionary struggle to turn gene expression up or down — could play a crucial part in determining the balance or imbalance of an offspring’s brain. If this proves true, it would greatly clarify the diagnosis of mental disorders. It might even make it possible to reset the mind’s balance with targeted drugs.
The article then goes on to propose the idea (presumably related to a similar Chris Frith theory) that autism and psychosis might be ‘diametric opposites’, echoing an argument they expanded on more fully in a larger article earlier this year.
I’ve not read the bigger piece, but my first thought is how they manage to account for the fact that people with Asperger’s or autism can become psychotic. I shall look forward to seeing what they have to say in more detail.
Anyway, the podcast discusses the main points, as well as getting some comments from some more sceptical scientists.
Link to NeuroPod homepage (now with flash streaming).
mp3 of August Neuropod.
Link to piece on genetic imprinting and psychiatric disorder.
Link to PubMed entry for same.
Mind Hacks 