Synapse

Signal Transduction Across the Synapse

When the wave of Action Potentials reach the end of the axon the electrical signal is converted into a chemical signal. This chemical or neurotransmitter crosses the space (Synapse) between adjacent neurons and initiates an Action Potential on another neuron.

The action potential activates a calcium channel and Ca++ diffuses into the neuron.

This Ca++ causes vesicles to fuse with the cell membrane. Through exocytosis, neurotransmitters (chemicals) are released into the synapse.

These neurotransmitters diffuse across the synapse and bind to receptors on another neuron. This causes special Na+ channels to open and an action potential is initiated in the next neuron.

The following animation shows this process.

Once the message has been passed on to the next neuron, the neurotransmitter is reabsorbed into the axon, diffuses away or it is destroyed by an enzyme. Back Home Reproduction without permission is strictly prohibited. © Copyright 1999 Terry Brown. All rights reserved.