Researchers from Allen Institute for Brain Science in Seattle discovered ‘rosehip neuron’ that has unique genes, distinctive shape and diverse connections with other neurons.
Dendrites of neurons receive signals from other neurons. The researchers from Allen Institute for Brain Science in Seattle found that dendrites in the rosehip cells are compact with several branch points, which gives the neuron the appearance of a rosehip. Moreover, the new neuron is characterized by large bulbs at the end of their axons that release neurotransmitters or chemical signals to other neurons. The research was published in the journal Nature Neuroscience on August 27, 2018.
The researchers examined the brain tissue of two deceased middle-age men to document the new neuron. The researchers found distinct functionality in the neuron compared to other neurons when the genes of the rosehip neuron in post-mortem tissue were analyzed. Several genes in the rosehip neuron turned on compared to other cells. The rosehip neuron was further documented by studying the electrical activity and shapes of neurons in isolated, living brain tissues.
The late discovery of rosehip neuron is attributed to the rarity of these cells in the brain. Moreover, human brain tissue is difficult to obtain for study. The researchers examined only one layer of the brain and suggested that the rosehip neurons could be found in other layers. The new neurons make up around 10% of the first layer of the neocortex, which is involved in sight and hearing. Moreover, the new neurons connect to neurons called pyramidal cells that make up two-thirds of all the neurons in the cortex. Although the researchers found that rosehip neurons act as inhibitory neurons, the full extent of the rosehip neurons relationship to the pyramidal neurons is unclear. The researchers analyzed mice brain in order to find evidence of the rosehip neuron in the animal. However, no genetic trace of the new neuron was found in the mice brain. The researchers stated that the less number of cortex cells in mice compared to human cortex cells might be responsible for the absence of rosehip neuron in mice.