Scientists have discovered a new type of neuron, not found in mice, that may help uncover what sets our brains apart from other animals, according to an NPR report. The discovery of what have been dubbed “rosehip neurons” could also help to explain why some neurological treatments work in experiments with mice, but not with humans. Additionally, it may provide new information on a range of neurological disorders from autism to schizophrenia.
“This particular type of cell had properties that had never actually been described in another species,” according to Ed Lein, an investigator with the Allen Institute for Brain Science in Seattle, and one of the authors of the study.
While researchers have in the past suggested that other types of neurons could be unique to humans, they were ultimately found in other species, or were less thoroughly documented by evidence. And Lein notes that the rosehip neurons may still be found in primates such as chimpanzees.
The discovery came during research documenting brain cells with microscopic study of anatomy and genetic analysis of cells, according to Science. The rosehip neurons are small and dense, with bulbous structures at “axonal buttons” where signals are sent to other cells. The shape of these structures led a team at the University of Szeged, in Hungary, to name them after rosehips.
The researchers reported in Nature Neuroscience that the cells don’t match any neurons in the mice that are frequently used as a model for human brains, leading to questions on whether these cells may play a role in brain functions that distinguish humans from other animals such as mice.
The neurons are most concentrated in the first layer of cortex, where they make up 10 to 15 percent of inhibitory neurons there, suggesting they may play a role in slowing other neurons and mitigating responses to incoming signals. Since they seem to be a type of inhibitory neuron, a dysfunction in these cells could be linked closely to mental illness.
One implication of the finding is that “it throws some doubt on the ability to use the mouse to study certain elements of human function and disease,” according to Lein. “These types of cells are extremely important.” Dysfunction of such cells, Lein says, can “directly be linked to different types of neuropsychiatric disease, like schizophrenia.”