Effect of Amphetamine on Neurotransmitter Release and Reuptake

Author Paul Kenyon
Amphetamine releases catecholamines (especially dopamine) from synaptic vesicles in nerve terminals. Note that amphetamine causes a massive release of DA from synaptic vesicles within the presynaptic nerve ending which causes the postsynaptic neuron to fire.

1. Bridging the information gap between neurones

Neurotransmitters are responsible for transmitting information across the synaptic gap between neurones.

Neurotransmitters are stored in synaptic vesicles. When amphetamine is administered:

  • synaptic vesicles attach themselves to the presynaptic membrane, then
  • break open and spill neurotransmitter into the synaptic cleft.

Neurotransmitters in the synaptic cleft :

  • attach to postsynaptic receptor sites and trigger an action potential in the postsynaptic membrane
  • some neurotransmitter attaches to presynaptic receptors (autoreceptors) located on the membrane (pre-synaptic membrane) of the cell that originally released them

2. 'Mopping up' after information transmission

After transmitters have been released into the synaptic cleft.

Transmitters become detached from receptors and either:

  • diffuse through extracellular fluid (red transmitter), or
  • undergo reuptake (blue transmitter), or
  • are broken down by enzymes (yellow transmitter)

 Last updated 09/02/07
Copyright Dr. C.A.P. Kenyon 2000-07