Our Brains Are More Like Birds' Than We Thought
Sunday, July 04 2010 @ 03:55 PM EDT
Contributed by: jkr
ScienceDaily (July 2, 2010) — For more than a century, neuroscientists believed that the brains of humans and other mammals differed from the brains of other animals, such as birds (and so were presumably better). This belief was based, in part, upon the readily evident physical structure of the neocortex, the region of the brain responsible for complex cognitive behaviors.
A new study, however, by researchers at the University of California, San Diego School of Medicine finds that a comparable region in the brains of chickens concerned with analyzing auditory inputs is constructed similarly to that of mammals.
"And so ends, perhaps, this claim of mammalian uniqueness," said Harvey J. Karten, MD, professor in the Department of Neurosciences at UCSD's School of Medicine, and lead author of the study, published this week in the Proceedings of the National Academy of Sciences Online Early Edition.
Generally speaking, the brains of mammals have long been presumed to be more highly evolved and developed than the brains of other animals, in part based upon the distinctive structure of the mammalian forebrain and neocortex -- a part of the brain's outer layer where complex cognitive functions are centered.
Specifically, the mammalian neocortex features layers of cells (lamination) connected by radially arrayed columns of other cells, forming functional modules characterized by neuronal types and specific connections. Early studies of homologous regions in nonmammalian brains had found no similar arrangement, leading to the presumption that neocortical cells and circuits in mammals were singular in nature.
For 40 years, Karten and colleagues have worked to upend this thinking.
Read more: www.sciencedaily.com/releases/2010/07/100702152407.htm