Inhibitory vs Excitatory: Difference and Comparison

Inhibitory means preventing a certain action; therefore, an inhibitory transmitter does not allow an electrical signal to reach the neuron. On the other hand, an excitatory transmitter does just the opposite.

Both these terms (Inhibitory and Excitatory) are medical terms, and they have got different meanings, thus making a huge difference between them.

However, to be more specific, these two terms are related to the nervous system of our body. People can get mistaken about the meaning of these two terms.

You all will know that the human body comprises the spinal cord, neurons, peripheral brain ganglia, and neurons. Well, the nervous system is one of the important parts of the human body.

With the help of the nervous system, we sense different kinds of feeling like the feeling of touch, light, and other such things.

Key Takeaways

1. Inhibitory refers to neurotransmitters or signals that reduce the activity of neurons in the brain. In contrast, Excitatory refers to neurotransmitters or signals that increase the activity of neurons in the brain.
2. Inhibitory signals promote calmness and relaxation, while Excitatory signals promote alertness and arousal.
3. Inhibitory signals can prevent overstimulation and maintain balance in the brain, while Excitatory signals can lead to excessive stimulation and imbalance.

Inhibitory vs Excitatory

Excitatory neurotransmitters, such as glutamate, increase the activity of neurons and make them more likely to fire an action potential, which is the electrical signal that neurons use to communicate with each other. Inhibitory neurotransmitters, such as GABA (gamma-aminobutyric acid), decrease the activity of neurons and make them less likely to fire an action potential. 

Comparison Table

Parameters of Comparison	Inhibitory	Excitatory
Function of transmitters	An inhibitory transmitter prevents a neuron from taking the firing action.	On the other hand, the excitatory transmitter formulates and sends an electrical signal called action potential to the receiving neuron.
Polarizing neurotransmitters	The inhibitory depolarizes the neurotransmitters in the postsynaptic membrane.	The excitatory polarizes the neurotransmitters in the postsynaptic membrane.
Stimulation of neurotransmitters	The inhibitory synapses inhibit the neurotransmitters.	The excitatory synapse, on the other hand, stimulates the neurotransmitters.
Examples	Glycine is an amino acid that will slow down the electrical movements in the nervous system. Another example would be GABA (gamma-aminobutyric acid)	Glutamatergic is a type of amino acid considered the main transmitter of excitatory in the nervous system of human beings. Some other examples include acetylcholine, serotonin, and many others.
Purpose	The main purpose of inhibitors is to block the reaction rate in the human body or even slow it down.	The function of excitatory is to promote the electrical signals in the body. The electrical signal created is also called an action potential.

What is Inhibitory?

Inhibitory is a term used in the field of medical studies. However, the inhibitory postsynaptic potential is a type of synaptic potential that prevents or blocks the generation of an action potential.

The inhibitory neuron falls under the central nervous system and plays a significant role in the human body.

While the inhibitory transmitter is a transmitter that creates a signal called the ‘action potential’. The job of the transmitter is to prevent receiving the action potential.

A synapse in a neuron can be either inhibitory or excitatory. Synapses are a junction that helps a neuron sends signals to another cell.

The inhibitory synapses facilitate the decrease of the likelihood of a fire action from happening. Surprisingly, a human neuron cannot be both inhibitory and as well as excitatory at the same time.

Inhibitory prevents sending any firing action to the receiving neuron and helps during an ongoing surgery. The doctors use glycine so that the electrical activity in the patient’s nervous system slows, making it easier for the doctors to conduct their surgery on them.  

What is Excitatory?

Excitatory, on the other hand, performs tasks that are the opposite of inhibitory functions. Here, the excitatory neuron is more likely to fire an action. An excitatory transmitter helps an electrical signal, also called an action potential, to generate in the receiving neuron.

Drugs are the best example of excitatory that creates this kind of fire activity in the neuron. Nicotine, cocaine, and amphetamines are some drugs that, when consumed, will make the neuron fire an action.

Drugs like cocaine and nicotine affect the human nervous system’s neurons, increasing the chances of the neuron firing an action.

Main Differences Between Inhibitory and Excitatory

1. The inhibitory prevents the chances of a neuron from firing an action, whereas the excitatory transmitters increase the likelihood of firing an action.
2. The neurons of human beings cannot be both inhibitory and as well as excitatory at the same time.
3. The stimulation of neurotransmitters occurs in the excitatory synapses, whereas in the inhibitory synapses, those neurotransmitters are inhibited.
4. The purpose of inhibitory or inhibition is to block or prevent certain impulses from taking some action, whereas the excitatory is just the opposite.
5. A person wants to hit somebody mainly because of the excitatory neuron, which makes them take action, whereas the inhibitory transmitter does not allow that to happen.

References

1. https://journals.sagepub.com/doi/abs/10.1038/jcbfm.1985.56
2. https://www.sciencedirect.com/science/article/pii/0301008294900825
3. https://www.sciencedirect.com/science/article/pii/089662739390221C

Last Updated : 11 June, 2023