How a signal crosses a synapse
The meeting point between two nerve cells is called a synapse. When an electrical impulse reaches the sending cell’s tip, it triggers tiny packets inside the cell to release neurotransmitters—chemical messengers—into the narrow space between cells.
On the other side, matching receptors act like selective docking sites. When neurotransmitters bind to them, they change the receiving cell’s activity. Depending on the messenger and receptor, that change can make the next electrical impulse more likely or less likely. The message is therefore not simply passed along unchanged; each connection can help amplify, dampen, or shape what happens next.
Why the message does not linger
Afterward, neurotransmitters are cleared from the gap. Some are taken back up by the sending cell for reuse; others are broken down or carried away. This reset lets the connection respond to another signal rather than remaining switched on.
Because one nerve cell can receive input from many others, the receiving cell combines signals across its connections. Whether it fires depends in part on the balance of those inputs. A tiny chemical handoff can thus help determine whether a larger message travels onward through a circuit.
