What happens at the synapse between two neurons?

At the synapse between two neurons, the following steps occur:

1. An electrical signal, known as an action potential, travels down the axon of the neuron.

2. When this signal reaches the end of the neuron (the presynaptic terminal), it triggers the release of neurotransmitters. These are chemical messengers stored in small sacs called vesicles.

3. The neurotransmitters cross the synaptic cleft, which is the gap between the two neurons.

4. The neurotransmitters then bind to specific receptors on the second neuron (the postsynaptic neuron). This can either stimulate or inhibit a new action potential in the second neuron.

5. After the neurotransmitters have transmitted their signal, they are either broken down by enzymes, taken back up into the first neuron (a process called reuptake), or diffuse away.

6. If the signal is strong enough and reaches the threshold, the postsynaptic neuron will fire, sending the signal down its axon and onto the next neuron. If the signal is not strong enough, the postsynaptic neuron will not fire.

7. This process repeats, allowing the signal to travel from neuron to neuron, enabling communication throughout the brain and body.