The human brain has many mysteries, and neuroscientists still don’t know what makes it special and different from the brains of animals.
A team of scientists at the Allen Institute for Brain Science led by Ed Lein, Ph.D. and Gábor Tamás, Ph.D. (University of Szeged in Szeged, Hungary) found a new type of human brain cell – a cell never seen in mice and other laboratory animals.
“We really don’t understand what makes the human brain special. Studying the differences at the level of cells and circuits is a good place to start, and now we have new tools to do just that,” said Lein.
So they started looking for some answers and discovered the new brain cell they call “rosehip neurons,” describing their findings in the journal Nature Neuroscience.
What Are Rosehip Neurons?
These new brain cells were a dense gathering of axons of each brain cell around the center of the cell, and imaging shows it looking like a rose without its petals – thus the name ‘rosehip.’ These new cells belong to a class of inhibitory neurons, which make other neurons in the brain cease their activity.
The study did not prove that this cell is only found in humans. It could appear in primate brains, but not in rodents. So, rosehip neurons can be added to the list of specialized neurons that are found in humans and could exist in primates.
Rosehip neurons attach to one part of their cellular partner, meaning that they would control information flow in a certain way. Tamás compares the cell to the brakes of a car, which work in particular spots:
“This particular cell type—or car type—can stop at places other cell types cannot stop. The car or cell types participating in the traffic of a rodent brain cannot stop in these places.”
The next step for the team would be to see if the brains of people with neuropsychiatric disorders contain rosehip neurons that were damaged by disease.
Samples of Brains
The research started with analyzing the brain of two deceased men in their 50s who donated their bodies to research. The team took samples from the cortex, which according to Lein, it is “the most complex part of the brain, and generally accepted to be the most complex structure in nature.”
The research lab in Hungary where Tamás works studies the human brain, analyzing the cells’ shapes and their electrical properties. The Allen Institute focuses on genes that make human brain cells unique from others and from those of other species (like mice).
A few years ago, Tamás visited the Allen Institute and showed his research on a different brain cell type, and the Allen research group said they found the same cell – each using different techniques:
“We realized that we were converging on the same cell type from absolutely different points of view,” said Tamás.
Tamás concludes that unlike other human organs, the human brain cannot be modeled in an animal model and that the output of our brain is the one that sets humans apart from the animal kingdom:
“So it turns out humanity is very difficult to model in an animal system.”
Andre Blair s is the lead editor for Advocator.ca. He holds a B.A. in Psychology from the University of Toronto, and a Master of Science in Public Health (M.S.P.H.) from the School of Public Health, Department of Health Administration, at the University of North Carolina at Chapel Hill. Andre specializes in environmental health, but writes on a variety of issues.