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October 31 2014
TL - 11
Biological Foundations of Behaviour.
An individual neuron is not that complicated. They recieve a signal,
then may re-transmit the signal. The structure of how the neurons are
wired is from which complex behaviour rises. Act somewhat like wires.
At rest, when a neuron is not being stimulated, it holds a
-70 mV. It maintains this negative charge in several ways.
forces, an even distribution of all its component pieces. The
inside and outside of the neuron are trying to reach balance.
At rest potassium ions are free to travel in and out of the
protien gates on the neuron's cell membrane. Typically, this
more sodium ions outside than inside. There are two gates, one
and one for potassium.
In addition, there is also a sodium/potassium pump which activly
transporting ions. 3 sodium out, 2 potassium in. The net result
both active and passive modes is more sodium out, more potassium
Exterior has positive charge, interior has negative charge.
When a neuron is stimulated, the ion pump shuts down, the
closes, and the sodium gate opens. Sodium ions flood in and the
gets a +40mV charge.
After the neuron has been stimulated, it must go through a phase
the charges rebalance to the original -70mV
A neuron can fire as fast as 100-1000 cycles per second.