EPSP and IPSP
- A PSP is a post-synaptic potential. This is the potential generated by activation of a single synapse. This can be
- Excitatory (EPSP)- usually depolarises the post-synaptic cell
- Inhibitory (IPSP)- usually hyperpolarises the post-synaptic cell
- NB Rarely will a single EPSP generate a post-synaptic action potention. More than one is usually needed. They can be combined in one of two ways:
- In response to a graded potential, the membrane potential takes time to return to its normal resting state.
- If one excitatory input depolarise the cell in quick succession, the graded potentials can effectively ‘piggy-back’ on one another, adding up their effect.
- This is when more than one excitatory input stimulates the post-synaptic cell simultaneously, adding their effect to one another.