Indeed, the pyramidal neurons constitute together a continuous network
extending over the entire neocortex, justifying the generalization: the neocortex
communicates first and foremost within itself!
The neurons from different layers communicate via axo-dendritic synapses,
which are chemical informational junctions that transfer information via
neuromediator molecules. The neuromediator molecules released from the
axonal terminal under depolarization (membrane firing; incoming electric
impulse) bind to postsynaptic (dendritic) ion channels, modulate their ion
conductivity and generate again electric impulses. Thus the electromagnetic
events are essential in neuronal functioning, informational transfer and
processing.
Electromagnetic sensory input to the cortex
The experiments with implanting electrodes directly into the brain cortex suggest
that the cortex is the residence for conscious experience. This notion is well
supported with clinical data.
William Dobelle, M.D. (2000) has helped a blind man to see again using
electrodes implanted into his brain and connected to a tiny television camera
mounted on a pair of glasses. Although he does not "see" in the conventional
sense, he can make out the outlines of objects, large letters and numbers on a
contrasting background, and can use the direct digital input to operate a
computer. The man, identified only as Jerry, has been blind since age 36 after a
blow to the head. Now 64, he volunteered for the study and got a brain implant in
1978. There has been no infection or rejection in the past 24 years.