Receptors The neurotransmitters—in our example, acetylcholine, a common variety—bind onto receptors (shown here as green blossoms) on the surface of the recipient neuron. This opens channels in the cell surface through which enter ions, or charged atoms, of sodium. This generates a current across the membrane of the receiving cell, which completes delivery of the "message." Previous | Next Resources | Teacher's Guide | Transcript | Site Map | Search for a Safe Cigarette Home Search | Site Map | Previously Featured | Schedule | Feedback | Teachers | Shop Join Us/E-Mail | About NOVA | Editor's Picks | Watch NOVAs online | To print PBS Online | NOVA Online | WGBH © | Updated October 2001 |