Postsynaptic Neuron

« Back to Glossary Index

The postsynaptic (after the synapse) neuron receives neurotransmitters (chemical messengers) from the presynaptic axon terminal. The specialized postsynaptic membrane, with receptor proteins and enzymes, responds to incoming signals:

• Depolarizing neurotransmitters cause the neuron’s resting membrane potential (neurons at rest have a negative charge inside compared to outside) to become less negative and more likely to fire an action potential (exciting the neuron). Glutamate and noradrenaline are common excitatory neurotransmitters, causing depolarization in the postsynaptic neuron.
• Hyperpolarizing causes the resting membrane potential to become more negative and less likely to fire an action potential (inhibiting the neuron). Serotonin and GABA are inhibitory neurotransmitters, causing hyperpolarization in the postsynaptic neuron.