Artificial Consciousness/Neural Correlates/Synaptic Models/Post-Syanptic (Sensitive Patch) Model
Post Synaptic (Sensitive Patch) Model
[edit | edit source]As you probably know by now, all synapses consist of a pre-synaptic bud, on the sending neuron, a Sensitive patch on the receiving neuron, and a gap filled with extracellular fluid called the Synaptic gap. The Neuro-Transmitters are secreted by the pre-synaptic bud, diffuse across the synaptic gap and are detected by the sensitive patch.
Just, as it is the Activation Potential of the sending neuron, that determines at least partially how much neuro-transmitter is secreted, The purpose of the sensitive patch, is to convert the chemical signals back into an electrical charge and thus Action Potential in the receiving Neuron.
To do this, the sensitive patch has to do two things, it has to detect the presence of small amounts of neuro-transmitter, and somehow convert those detections into an electrical charge. There are two separate mechanisms that the neuron uses to achieve these effects, Permease Molecules that detect and transmit the detection of Neuro-Transmitters into the cell where they can influence the cell, and Ion Channels that pump specific ions into or out of the cell and into or out of the extracellular fluid across the cell membrane.
An interesting note, is that these Sensitive Patches persist despite the fact that the Cellular Membrane that they interpenetrate is replaced periodically as part of the survival mechanism of the cell. Another interesting fact, is that depending on which ion is transferred and in which direction, the electrical characteristics of the neuron change. Some ions when pumped into the neuron increase the Activation Potential, Some Ions when pumped out of the neuron increase the Activation potential,
Some ions when pumped into the cell, decrease habituation, and some ions when pumped out of the cell increase the Potentiation of the Cell, While other Ions pumped into the cell act to shunt the cell keeping it from firing.
Each Synaptic Sensitive Patch, is associated with specific Ion channels and specific permease molecules that act like keyholes that only certain neuro-transmitters will activate, as a result, certain Neuro-Transmitters are associated most often with certain ion channels in a specific type of neuron. The combination of different types of Sensitive Patches with different phenotypes of neurons produce upwards of 150 different types of neurons in the Mammalian brain. Different types of Neurons tend to specialize in different types of processing probably because their phenotypes and sensitive patches are tuned to that type of processing. DNA probably determines which types of Neurons can be found in which parts of the Nervous System.