# Medical Cell assembly

1. Jun 24, 2006

### Math Is Hard

Staff Emeritus
I just started reading about Donald O. Hebb and his theories about cell assemblies. I am stuck on something really simple. From what I have read, if two neurons have a synaptic connection and they fire simultaneously, then that connection will be strengthened. What I can't understand is this - if neuron A has a connection with neuron B...

Does neuron A fire and cause neuron B to fire, and then while neuron B is firing, neuron A is still firing and that makes it a simultaneous event?
A->B
Or does neuron C cause neuron A to fire while neuron D simultaneously causes neuron B to fire and that's what makes it a simultaneous event?
C->A
D->B
I hope I am making sense. Thanks for any help.

2. Jul 11, 2006

### Math Is Hard

Staff Emeritus
nobody? well, nevermind. I think I got my answer today in class. I believe it's the latter idea.

3. Jul 11, 2006

### neurocomp2003

The idea is "Neurons that fire together wire together"...however it means that if neuron A is connected to neuron B then if neuron A fires and then neuron B fires => the synaptic strength AB increases(either by myelin sheath or by # of synaptic knobs) however if the neuron B fires before neuron A(either nothing happens or the strength decreases). Note that neuron A may not be the sole cause of neuron B...for example given the letters you stated above. lets say A and C are both connected to B...A may be the weaker neuron but if it fires with C such that B receives both at the same time the AB will also increase.

Also I wouldn't neglect your 2nd example. They would resemble what NeuralNetwork literature calls Cooperation or Competition(inhibition). Hebb's rule is the simplest Rule and it might through Cellular Automaton theory create more complex rules such as the two mentioned previously.

Remember the brain is N-Body problem w.r.t. Neurons.

Last edited: Jul 11, 2006
4. Jul 11, 2006

### Math Is Hard

Staff Emeritus
Thanks for the help! I am glad to see you around again.

5. Jul 11, 2006

### neurocomp2003

thank you and i hoped what i said helped. I also forgot to mention that you could have a BA synapse if you wanted to