Microscopic vs. Mesoscopic

private, intracellular, microscopic view
microscopic pulse and wave state variables to describe the activity of the single neuron
time scale: thousandths of a second and thousandths of a millimeter

public, extracellular, mesoscopic view
mesoscopic state variables to describe the collective activities
time scale: tenths of a second and tenths of a millimeter

Mass Activity

recording from outside the cell: simultaneous firing of the pulses of many neurons in a neighborhood

measuring the electrical potential difference between the surface and the depth of the cortex (outer layer of brain)

neurons in population generate background activity by continually sending pulses to each other at random,
whether or not there is sensory input or motor output?!

Sigmoid Curve Explanation for the Ensemble

as the wave density in a neighborhood goes to the inhibitory side:
• pulse density goes to zero with decreasing firing probability of axons in neighborhood

as wave density goes to the excitatory side:
• trigger zones in the population encounter the refractory periods progressively,
• pulse density approaches an upper limit, because neurons need to recover between pulses:
  (as neurons in neighborhood are excited, there is an increase in number of cells still recovering from previous activity).

synapses cannot be driven too far outside their normal ranges:
• wave-pulse precedes the pulse-wave and sets the boundaries