The answer to better artificial intelligence or even the cure for autism may lie in one of the most fickle cells in the body.
The little-understood Purkinje cells, which form in a single layer within the cerebellum in the base of the brain, aids in controlling balance, coordination and for learning new motor skills that enable us to ride a bicycle, painting or even learning musical instruments.
However, a study by researchers from the National Centre for Biological Sciences (NCBS), Bengaluru, shows that these nerve cells have the innate ability to either follow or ignore instructions of the brain.
This ‘moodiness’ of the Purkinje cell was found to depend on the voltage across membranes. When the inside of the cell was more negative than the outside, the signals in the Purkinje cells remained silent until “instructions” from other parts of the brain sent it into a flurry of activity.
This obedient mood was called ‘down’ state by the researchers. However, when the inside was less negative than the outside, the cells went into an ‘up’ mode where impulses were sent at a constant rate despite receiving signals coming from the other parts of the brain.
“We have shown that a more negative voltage helps the neuron pay attention to signals it receives while a less negative voltage puts it in ‘do not disturb’ mode,” says Vatsala Thirumalai, an NCBS scientist who authored the paper – along with her graduate student Mohini Sengupta – published recently in the journal eLife. However, only further experiments can determine why the voltages in the cell change, she said.
Several conditions such as alcoholism, autism and ataxias (a condition resulting in lack of muscular coordination) affect Purkinje neuron function, and understanding the working of the cells can help design therapies for improving motor skills, Dr. Vatsala said. Apart from the medical potential, the study can also aid in designing robots that have the dexterity of the human hand. “By drawing inspiration from Purkinje neurons, it may be possible to design better robots that learn fine movements,” she said.
The intricacies of the cells were revealed by observing the Zebrafish (found in Ganga and Brahmaputra), which is nearly transperant and does not have a fully-grown skull. Nerve cells in the brain were made to glow by injecting DNA, while a paralytic agent, which does not affect signals in the brain, was used to keep the fish stationary.
