Nov. 7, 2012 After a short period of growth, cultured networks
of neurons regularly exhibit major activity in the absence of
external stimulation. These "bursts" are entirely related to
growth. At this stage, they have little to do with learning
behaviour, as the network is still too young to sustain a
process of memory formation. This has now for the first time
been simulated for networks ranging in size from 10,000 to
50,000 neurons. The simulations provide insight into the role of
the growth process in initial activity. Researchers at the
University of Twente's MIRA Institute recently published details
of this work in PLOS ONE. "Isolated" neurons, which have yet to
form any interconnections, soon put out cell extensions (axons
and dendrites) that connect them to other neurons. The resultant
network starts to show signs of activity after just one week.
The researchers made these observations in networks that they
had cultured from neurons extracted from the brains of young
rats. These cells were grown in cu