In a breakthrough, scientists, led by an Indian-origin researcher, have successfully converted adult human blood cells into neurons.
Researchers can now directly convert adult human blood cells to both central nervous system (brain and spinal cord) neurons as well as neurons in the peripheral nervous system (rest of the body) that are responsible for pain, temperature and itch perception.
This means that how a person's nervous system cells react and respond to stimuli, can be determined from his blood, researchers said.
The breakthrough was led by Mick Bhatia, director of the Stem Cell and Cancer Research Institute at McMaster University.
Currently, scientists and physicians have a limited understanding of the complex issue of pain and how to treat it.
The peripheral nervous system is made up of different types of nerves - some are mechanical (feel pressure) and others detect temperature (heat).
In extreme conditions, pain or numbness is perceived by the brain using signals sent by these peripheral nerves.
"The problem is that unlike blood, a skin sample or even a tissue biopsy, you can't take a piece of a patient's neural system. It runs like complex wiring throughout the body and portions cannot be sampled for study," said Bhatia.
"Now we can take easy to obtain blood samples, and make the main cell types of neurological systems - the central nervous system and the peripheral nervous system - in a dish that is specialised for each patient," said Bhatia.
"Nobody has ever done this with adult blood. Ever," Bhatia said.
"We can actually take a patient's blood sample, as routinely performed in a doctor's office, and with it we can produce one million sensory neurons, that make up the peripheral nerves in short order with this new approach.
We can also make central nervous system cells, as the blood to neural conversion technology we developed creates neural stem cells during the process of conversion," said Bhatia.
The team's revolutionary, patented direct conversion technology has "broad and immediate applications," said Bhatia.
It also paves the way for the discovery of new pain drugs that don't just numb the perception of pain, Bhatia said.
Bhatia's team successfully tested their process using fresh blood, but also cryopreserved (frozen) blood.
Since blood samples are taken and frozen with many clinical trials, this allows them "almost a bit of a time machine" to go back and explore questions around pain or neuropathy to run tests on neurons created from blood samples of patients taken in past clinical trials where responses and outcomes have already been recorded."
The study was published in the journal Cell Reports.
