This model is a simplistic attempt to represent cellular communication. The dendrites at the top of the neuron receive input from the neurotransmitters and increase a stored variable which, when it reaches a certain point, will tell the neuron to " fire". This process is intended to mimic the way in which, during depolarization, the difference between the ionic concentration inside and outside the cell will gradually reach equilibrium, and the cell will then experience a massive influx of positively charged ions, bringing the membrane potential to a sudden positive spike. The firing in this model is shown by a red line that descends along the neural axon. When the depolarization reaches the terminals at the ends of the axon, the neuron releases a set of neurotransmitters which communicate the signal to the next cell.
Because NetLogo allows a wrap of patches around the screen, the neuron at the bottom is able to communicate with the neuron at the top, setting up a very small looped signal. Over time, as the amount of neurotransmitters present in the cellular space increases, firing occurs in increasingly rapid sequences. In order to minimize this effect, the number of neurotransmitters stored in the terminus has to take time to refresh before it can be fired, similar to the actual cellular necessity to generate new neurotransmitters in real cellular communication.
How to use it:
The SETUP button will draw the neurons and prepared them for the initial firing.
The GO button will ask the neurons to asses a neurotransmitter has attached to the dendrite.
If it has, the membrane potential will decrease.
When the potential reaches 0, the cell will fire.
The levels of the two different types of neurotransmitters can be altered using the sliders.
A count of the neurotransmitters present in the cellular space if provided.
The graph shows the action potential of the top neuron.
created with NetLogo
view/download model file: communication.nlogo