Neurons - Transmission of Information

Neurotransmitters

Chemical signals sent between from neurons to other neurons, muscles or glands to cause changes in the receiver cell. E.g:

• Receiving Neurons convey electrical signals

• Receiving Muscles to contract

• Receiving Glands to secrete

Synapse/Synaptic cleft

The space between the axon terminal of the pre-synaptic neuron and the receiver cell where neurotransmitters travel.

Synaptic transmission

1. Action potential travelling down the axon reaches the designated axon terminal

2. The electrical signal of the action potential triggers the release of stored neurotransmitters

3. Neurotransmitters travel the synaptic cleft, the space between the current neuron and the receiving cell.

4. The neurotransmitters bind to receptors on the post-synaptic membrane (e.g the dendrites of neurons)

5. This binding can trigger an action potential in the receiving neuron.

Drugs and neurotransmitters

Dopamine is a neurotransmitter, which when bound to a receptor emulates feelings of accomplishment and pleasure.

Many drugs increase dopamine release or prevent its removal from receptors, resulting in prolonged exposure to these feelings of accomplishment, which can become addictive.