Gasotransmitters, like NO, are synthesized in a neuron and can work in a retrograde fashion (acting on the presynaptic cell). How can NO travel to a presynaptic neuron when there are no specialized vesicles for it, and what keeps NO from traveling further from the releasing neuron?

What will be an ideal response?

Variations on gases can cross the lipid bilayer, but they are broken down very quickly, thus they can go to any adjacent cell but not further.