What is the Difference Between Neurotransmitter and Neuromodulator?

🆚 Go to Comparative Table 🆚

Neurotransmitters and neuromodulators are both chemical messengers involved in the transmission of signals between nerve cells, or neurons, in the nervous system. However, they have distinct differences in their functions, mechanisms of action, and effects on the body.

Neurotransmitters are:

  • Released from a neuron at an anatomically specialized junction, diffusing across a narrow cleft to affect one or sometimes two postsynaptic neurons, a muscle cell, or another effector cell.
  • Responsible for rapid signal transmission across synapses.
  • Examples include GABA, glutamate, and acetylcholine.

Neuromodulators, on the other hand, are:

  • Released from a neuron in the central nervous system or in the periphery, affecting groups of neurons or effector cells that have the appropriate receptors.
  • Not necessarily involved in the direct excitation or inhibition of neurons, but instead alter the responses of postsynaptic neurons to traditional neurotransmitters.
  • Often released more diffusely throughout the nervous system and can produce long-lasting effects.
  • Examples include dopamine, histamine, norepinephrine, and serotonin.

In summary, neurotransmitters are involved in rapid signal transmission between neurons, while neuromodulators play a more complex role in altering the responses of neurons to traditional neurotransmitters, often with long-lasting effects.

Comparative Table: Neurotransmitter vs Neuromodulator

Here is a table summarizing the differences between neurotransmitters and neuromodulators:

Property Neurotransmitters Neuromodulators
Definition Chemical substances that carry signals from one neuron to another across a synapse. Chemical substances that alter the activity of neurons and influence the release or reuptake of neurotransmitters.
Function Transmit signals or messages between nerve cells, enabling communication between neurons. Modulate the release or reuptake of neurotransmitters, affecting multiple neurons and having a more widespread influence.
Effects Rapid and short-lasting effects on nearby target neurons. Slow but long-lasting effects on a group of post-synaptic targets, which can be far away from the point of release.
Targets Specific target neurons via their receptors at synapses. Affects a group of post-synaptic targets, not limited to nearby neurons.
Examples Examples include glutamate, GABA, dopamine, and serotonin. Examples include norepinephrine, endorphins, and cortisol.

In summary, while both neurotransmitters and neuromodulators are involved in transmitting signals across nerve cells, they have distinct differences in their functions, mechanisms of action, and effects on the body. Neurotransmitters have rapid and specific effects on individual synapses, whereas neuromodulators have more widespread and longer-lasting effects on multiple neurons.