Ancient virus and human consciousness.
According to a paper published in the journal Cell, long ago a virus bound its generic code,
to the genome of four limbed animals.
The snippet of code is still very much alive in human brains today,
where it does the very vital task of packaging up genetic information,
and sending it from neuron cells to their neighbours,
in little capsules that look like viruses themselves.
These little packages of information might be critical elements of how nerves communicate,
and reorganise over time.
These tasks are thought to be necessary for higher order thinking.
It may sound surprising that bits of human genetic code come from viruses,
It is actually more common than we think.
It has been found that between 40 to 80% of the human genome,
arrived from some archaic viral invasion.
Viruses aren’t organisms that try to make a home in a body, the way bacteria do.
A virus is a genetic parasite.
It injects its genetic code into its host’s cells and hijacks them,
turning them to its own purposes.
When they do this, they act as factories for making more viruses.
This process is usually either useless or harmful to the host.
But, once in a while the injected viral genes are benign and useful.
It was found that viral genes seem to play important roles, in the immune system,
and in the early days of embryo development.
Not only is the ancient virus still active in the cells of human and animal brains,
but it seems to be important, for the process of thinking.
Shortly after a synapse fires, a viral gene known as Arc comes to life.
It writes its instructions down as bits of mobile genetic code known as RNA.
RNA is DNA’s messenger and agent in the world outside the cells nucleus.
It carries genetic instructions to places that can be useful.
Interestingly viruses tend to store their genetic information in RNA rather than DNA.
Following the Arc RNA’s instructions, the neuron cell builds ‘capsids’,
virus like envelopes around it.
These envelopes let it travel safely between cells.
It does just that, entering neighbouring neurons,
and passing its packet of genetic information along to them.
It is still unclear what that information does when it arrives in a new cell.
Researchers found that without the process functioning properly, synapses wither away.
Problems with Arc gene tend to show up in people with autism,
and other atypical neural conditions.
These processes underline brain functions ranging from classical operant conditioning,
to human cognition, and the concept of ‘self’.
Classical and operant conditioning are simple forms,
of reward and punishment based learning, in animals and humans.
Bizarrely, Arc seems to have made the jump from virus to animal more than once.
Scientists found that Arc genes in humans and other four limbed creatures,
are closely related.
The Arc gene in fruit flies and worms, seem to have arrived separately.
The next step in research, is to bring experts in neuroscience, an ancient viruses together,
to work out the mechanisms for just how Arc arrived in the genome,
and exactly what information, its passing between our cells today.