The hebbian synapse
Plasticity at the synapse
LTP :
- More vesicles in pre synapse
- More AMPA receptors on post synapse
- Bigger synapse
Time scales of synaptic plasticity
- Synaptic density size changes (Long term).
- AMPA/NMDA ratio changes (Long term).
- Number of spines changes (very Long term).
Hebb's Idea
Hebb’s Idea: If pathways of two types of modularities (i.e. visual and motor) often active together => association between the senses => then you learn (case B)
In other words: When axon of cell A repeatedly or persistently takes part in firing cell B, then A's efficiency in firing B will increase.
If A,B simultaneously active, $w \uparrow$
Adding neuromodulators such as dopamine can switch the whole thing.
