In fact, the ability of this neuron to distinguish the slightest difference in sound frequency is more than 30 times that of human auditory nerve. The reception frequency of human auditory cortex is obviously superior to that of other non-human mammals (except bats).
Interestingly, the researchers also pointed out that even people who have not received music training can detect extremely small frequency differences than peripheral auditory nerves. Using other peripheral nerves (such as nerves in the skin), human's ability to detect the difference between two points is limited by skin receptors. But when listening with ears, the sensitivity of this neuron exceeds that of any peripheral neuron.
The researchers implanted electrodes in different parts of the patient's brain, including areas that may be related to madness and auditory cortex. The researchers recorded the brain activity of patients while listening to random choruses of different artificially created tunes.
The test results surprised the researchers. A single human auditory neuron has amazing resolution in distinguishing extremely subtle frequency differences.
The researchers commented that the latest model of the laboratory's neurobiological research strength is to use the data at the level of single neurons in the living brain for research. Previous studies in this laboratory have identified a single neuron in the human hippocampus that is responsible for human navigation and a single cell that can translate different visual images.
Previously, a paper in Nature Genetics in 2005 took a step forward in clarifying the genetic pathway of hearing formation. This article describes in detail the process of sensory hair cells in the ear forming a unique shape that can accept sound.
Hair cells growing in the cochlea can convert mechanical vibration in the form of sound waves into chemical signals, and then transmit them to the brain. Dr. Chen Ping from Emory University School of Medicine and her colleagues found that the development of cochlea and hair cells depends on a genetic pathway called PCP (Planar Cell Polarity). The discovery of this pathway related to ear development may help researchers understand the molecular and genetic basis of deafness and provide important clues for the study of hearing recovery.
In the past 20 years, researchers have found that the special asymmetric shape of hair cells is a key part of their normal function, but it is not clear which gene is related to the formation of this asymmetric shape in the cochlea. Using a mouse model, Dr. Chen and her team found that the PCP pathway is related to the formation of cochlear and auditory hair cells. The mutation of this gene pathway will affect the shape of cochlea and the polarization of hair cells.
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