Table of ContentsView AllTable of ContentsHow They WorkCriteriaClassificationTypesPotential ProblemsMedications
Table of ContentsView All
View All
Table of Contents
How They Work
Criteria
Classification
Types
Potential Problems
Medications
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Ever wonder what’s going on in your brain when a certain mood strikes? You can thank your neurotransmitters. Neurotransmitters are tiny chemical messengers that carry, boost, and balance signals betweenneurons(aka nerve cells) and target cells throughout the body. These target cells may be in glands, muscles, or other neurons.
Billions of neurotransmitter molecules constantly work to keep our brains functioning, managing everything from breathing to heartbeat to learning and concentration levels. They can also affect various psychological functions, such as fear, mood, pleasure, and joy.
Some common neurotransmitters in the brain and body include serotonin, dopamine, glutamate, epinephrine, norepinephrine, andendorphins. They can influence everything from mood to focus, energy levels, sleep, and appetite.
Verywell / Jessica Olah
How Neurotransmitters Work
Neurons are not directly connected to one another. Instead, they need to find ways to communicate their signals to one another. To do this, they use neurotransmitters.
Crossing the Synapse
At the end of each neuron is a tiny gap called a synapse, and to communicate with the next cell, the signal needs to be able to cross this small space. This occurs through a process known as neurotransmission.
In most cases, a neurotransmitter is released from what’s known as the axon terminal after anaction potential(aka electrical signal) has reached the synapse, a place where neurons can transmit signals to each other.
When an electrical signal reaches the end of a neuron, it triggers the release of small sacs called vesicles, which contain neurotransmitters. These sacs spill their contents into the synapse, where the neurotransmitters then move across the gap toward the neighboring cells. These cells contain receptors where the neurotransmitters can bind and trigger changes in the cells.
Triggering a Response
After release, the neurotransmitter crosses the synaptic gap and attaches to the receptor site on the other neuron. It can either have an excitatory or inhibitory effect on the receiving neuron, depending on the neurotransmitter.
Receptors and neurotransmitters act like a lock-and-key system. Just as it takes the right key to open a specific lock, a neurotransmitter (the key) will only bind to a specific receptor (the lock). If the neurotransmitter is able to work on the receptor site, it triggers changes in the receiving cell.
Sometimes neurotransmitters can bind to receptors and cause an electrical signal to be transmitted down the cell (excitatory). In other cases, the neurotransmitter can actually block the signal from continuing, preventing the message from being carried on (inhibitory).
Inactivation of Neurotransmitters
Criteria for What Makes a Neurotransmitter
Identifying neurotransmitters can be quite difficult. While scientists can observe the vesicles containing neurotransmitters, figuring out what chemicals are stored in the vesicles is not quite so simple.
Because of this, neuroscientists have developed a number of guidelines for determining whether or not a chemical should be defined as a neurotransmitter:
Classification of Neurotransmitters
Neurotransmitters play a major role in everyday life and functioning. Scientists do not yet know exactly how many neurotransmitters exist, but more than 60 distinct chemical messengers have been identified.
Excitatory Neurotransmitters
These types of neurotransmitters have excitatory effects on the neuron, meaning they increase the likelihood that the neuron will fire an action potential. Some of the major excitatory neurotransmitters include epinephrine and norepinephrine.
Inhibitory Neurotransmitters
These types of neurotransmitters have inhibitory effects on the neuron; they decrease the likelihood that the neuron will fire an action potential. Some major inhibitory neurotransmitters include serotonin andgamma-aminobutyric acid (GABA).
Modulatory Neurotransmitters
Neurotransmitters that act as neuromodulators include acetylcholine, dopamine, serotonin, histamine, and cannabinoids.
Some neurotransmitters, such asacetylcholineand dopamine, can create both excitatory and inhibitory effects depending upon the type of receptors that are present.
Types of Neurotransmitters
There are a number of different ways to classify and categorize neurotransmitters. In some instances, they are simply divided into monoamines, amino acids, and peptides.
Neurotransmitters can also be categorized into one of six types:
Amino Acids
Peptides
Monoamines
Purines
Gasotransmitters
Acetylcholine
Problems With Neurotransmitters
As with many body processes, things can sometimes go awry. It is perhaps not surprising that a system as vast and complex as the human nervous system would be susceptible to problems.
A few of the things that might go wrong include:
Health professionals recognize the role that neurotransmitters can play in mental health conditions, which is why medications that influence the actions of the body’s chemical messengers are often prescribed to help treat a variety ofpsychiatric conditions.
Medications are sometimes used alone, but they may also be used in conjunction with other therapeutic treatments includingcognitive-behavioral therapy.
Drugs That Influence Neurotransmitters
Perhaps the greatest practical application for the discovery and detailed understanding of how neurotransmitters function has been the development of drugs that impact chemical transmission. These drugs are capable of changing the effects of neurotransmitters, which can alleviate the symptoms of some diseases.
Drugs that can influence neurotransmission include medications used to treat illnesses including depression and anxiety, such as selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, andbenzodiazepines.
Illicit drugs such asheroin,cocaine, andmarijuanaalso affect neurotransmission. Heroin acts as a direct-acting agonist, mimicking the brain’s natural opioids enough to stimulate their associated receptors. Cocaine is an example of an indirect-acting drug that influences the transmission of dopamine.
Takeaways
How Reuptake Inhibitor Drugs Work
18 SourcesVerywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Kuijpers M.Keeping synapses in shape: degradation pathways in the healthy and aging brain.Neuronal Signal. 2022;6(2):NS20210063. doi:10.1042/NS20210063Ayano G.Common neurotransmitters: criteria for neurotransmitters, key locations, classifications and functions.Am J Psychiatry Neurosci. 2017;4(6):91-95.Sukel K.Neurotransmission: neurotransmitters. The Dana Foundation.Boto T, Tomchik SM.The excitatory, the inhibitory, and the modulatory: mapping chemical neurotransmission in the brain.Neuron. 2019;101(5):763-765. doi:10.1016/j.neuron.2019.02.021Teleanu RI, Niculescu AG, Roza E, Vladâcenco O, Grumezescu AM, Teleanu DM.Neurotransmitters-Key factors in neurological and neurodegenerative disorders of the central nervous system.Int J Mol Sci. 2022;23(11):5954. doi:10.3390/ijms23115954Valenzuela CF, Puglia MP, Zucca S.Focus on: neurotransmitter systems.Alcohol Res Health. 2011;34(1):106–120.Wang R, Reddy PH.Role of glutamate and NMDA receptors in Alzheimer’s disease.J Alzheimers Dis. 2017;57(4):1041-1048. doi:10.3233/JAD-160763Magon, N & Kalra, S.The orgasmic history of oxytocin: love, lust and labor.Indian J Endocrinol Metab. 2011;15:S156-S161. doi:10.4103/2230-8210.84851.Schoenfeld TJ, Swanson C.A runner’s high for new neurons? Potential role for endorphins in exercise effects on adult neurogenesis.Biomolecules. 2021;11(8):1077. doi:10.3390/biom11081077Tank AW, Lee wong D.Peripheral and central effects of circulating catecholamines.Compr Physiol. 2015;5(1):1-15. doi:10.1002/cphy.c140007Nuutinen S, Panula P.Histamine in neurotransmission and brain diseases.Adv Exp Med Biol. 2010;709:95-107. doi:10.1007/978-1-4419-8056-4_10Klein MO, Battagello DS, Cardoso AR, Hauser DN, Bittencourt JC, Correa RG.Dopamine: Functions, signaling, and association with neurological diseases.Cell Mol Neurobiol. 2019;39(1):31-59. doi:10.1007/s10571-018-0632-3Albert PR, Vahid-Ansari F, Luckhart C.Serotonin-prefrontal cortical circuitry in anxiety and depression phenotypes: pivotal role of pre- and post-synaptic 5-HT1A receptor expression.Front Behav Neurosci. 2014;8:199. doi:10.3389/fnbeh.2014.00199Rajendran M, Dane E, Conley J, Tantama M.Imaging adenosine triphosphate (ATP).Biol Bull. 2016;231(1):73-84. doi:10.1086/689592Nowaczyk A, Kowalska M, Nowaczyk J, Grześk G.Carbon monoxide and nitric oxide as examples of the youngest class of transmitters.Int J Mol Sci. 2021;22(11):6029. doi:10.3390/ijms22116029National Center for Biotechnology Information. PubChem Database.Acetylcholine, CID=187.Berg KA, Clarke WP.Making sense of pharmacology: inverse agonism and functional selectivity.Int J Neuropsychopharmacol. 2018;21(10):962–977. doi:10.1093/ijnp/pyy071National Institute on Drug Abuse.The neurobiology of drug addiction.Additional ReadingKring, A M., Johnson, S L, Davison, GC, & Neale, J M.Abnormal Psychology. Hoboken, NJ: John Wiley & Sons; 2010.Verkhratsky, A & Krishtal, OA. Adenosine triphosphate (ATP) as a neurotransmitter. InEncyclopedia of Neuroscience, 4th Ed. Elsevier:115-123;2009.
18 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Kuijpers M.Keeping synapses in shape: degradation pathways in the healthy and aging brain.Neuronal Signal. 2022;6(2):NS20210063. doi:10.1042/NS20210063Ayano G.Common neurotransmitters: criteria for neurotransmitters, key locations, classifications and functions.Am J Psychiatry Neurosci. 2017;4(6):91-95.Sukel K.Neurotransmission: neurotransmitters. The Dana Foundation.Boto T, Tomchik SM.The excitatory, the inhibitory, and the modulatory: mapping chemical neurotransmission in the brain.Neuron. 2019;101(5):763-765. doi:10.1016/j.neuron.2019.02.021Teleanu RI, Niculescu AG, Roza E, Vladâcenco O, Grumezescu AM, Teleanu DM.Neurotransmitters-Key factors in neurological and neurodegenerative disorders of the central nervous system.Int J Mol Sci. 2022;23(11):5954. doi:10.3390/ijms23115954Valenzuela CF, Puglia MP, Zucca S.Focus on: neurotransmitter systems.Alcohol Res Health. 2011;34(1):106–120.Wang R, Reddy PH.Role of glutamate and NMDA receptors in Alzheimer’s disease.J Alzheimers Dis. 2017;57(4):1041-1048. doi:10.3233/JAD-160763Magon, N & Kalra, S.The orgasmic history of oxytocin: love, lust and labor.Indian J Endocrinol Metab. 2011;15:S156-S161. doi:10.4103/2230-8210.84851.Schoenfeld TJ, Swanson C.A runner’s high for new neurons? Potential role for endorphins in exercise effects on adult neurogenesis.Biomolecules. 2021;11(8):1077. doi:10.3390/biom11081077Tank AW, Lee wong D.Peripheral and central effects of circulating catecholamines.Compr Physiol. 2015;5(1):1-15. doi:10.1002/cphy.c140007Nuutinen S, Panula P.Histamine in neurotransmission and brain diseases.Adv Exp Med Biol. 2010;709:95-107. doi:10.1007/978-1-4419-8056-4_10Klein MO, Battagello DS, Cardoso AR, Hauser DN, Bittencourt JC, Correa RG.Dopamine: Functions, signaling, and association with neurological diseases.Cell Mol Neurobiol. 2019;39(1):31-59. doi:10.1007/s10571-018-0632-3Albert PR, Vahid-Ansari F, Luckhart C.Serotonin-prefrontal cortical circuitry in anxiety and depression phenotypes: pivotal role of pre- and post-synaptic 5-HT1A receptor expression.Front Behav Neurosci. 2014;8:199. doi:10.3389/fnbeh.2014.00199Rajendran M, Dane E, Conley J, Tantama M.Imaging adenosine triphosphate (ATP).Biol Bull. 2016;231(1):73-84. doi:10.1086/689592Nowaczyk A, Kowalska M, Nowaczyk J, Grześk G.Carbon monoxide and nitric oxide as examples of the youngest class of transmitters.Int J Mol Sci. 2021;22(11):6029. doi:10.3390/ijms22116029National Center for Biotechnology Information. PubChem Database.Acetylcholine, CID=187.Berg KA, Clarke WP.Making sense of pharmacology: inverse agonism and functional selectivity.Int J Neuropsychopharmacol. 2018;21(10):962–977. doi:10.1093/ijnp/pyy071National Institute on Drug Abuse.The neurobiology of drug addiction.Additional ReadingKring, A M., Johnson, S L, Davison, GC, & Neale, J M.Abnormal Psychology. Hoboken, NJ: John Wiley & Sons; 2010.Verkhratsky, A & Krishtal, OA. Adenosine triphosphate (ATP) as a neurotransmitter. InEncyclopedia of Neuroscience, 4th Ed. Elsevier:115-123;2009.
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Kuijpers M.Keeping synapses in shape: degradation pathways in the healthy and aging brain.Neuronal Signal. 2022;6(2):NS20210063. doi:10.1042/NS20210063Ayano G.Common neurotransmitters: criteria for neurotransmitters, key locations, classifications and functions.Am J Psychiatry Neurosci. 2017;4(6):91-95.Sukel K.Neurotransmission: neurotransmitters. The Dana Foundation.Boto T, Tomchik SM.The excitatory, the inhibitory, and the modulatory: mapping chemical neurotransmission in the brain.Neuron. 2019;101(5):763-765. doi:10.1016/j.neuron.2019.02.021Teleanu RI, Niculescu AG, Roza E, Vladâcenco O, Grumezescu AM, Teleanu DM.Neurotransmitters-Key factors in neurological and neurodegenerative disorders of the central nervous system.Int J Mol Sci. 2022;23(11):5954. doi:10.3390/ijms23115954Valenzuela CF, Puglia MP, Zucca S.Focus on: neurotransmitter systems.Alcohol Res Health. 2011;34(1):106–120.Wang R, Reddy PH.Role of glutamate and NMDA receptors in Alzheimer’s disease.J Alzheimers Dis. 2017;57(4):1041-1048. doi:10.3233/JAD-160763Magon, N & Kalra, S.The orgasmic history of oxytocin: love, lust and labor.Indian J Endocrinol Metab. 2011;15:S156-S161. doi:10.4103/2230-8210.84851.Schoenfeld TJ, Swanson C.A runner’s high for new neurons? Potential role for endorphins in exercise effects on adult neurogenesis.Biomolecules. 2021;11(8):1077. doi:10.3390/biom11081077Tank AW, Lee wong D.Peripheral and central effects of circulating catecholamines.Compr Physiol. 2015;5(1):1-15. doi:10.1002/cphy.c140007Nuutinen S, Panula P.Histamine in neurotransmission and brain diseases.Adv Exp Med Biol. 2010;709:95-107. doi:10.1007/978-1-4419-8056-4_10Klein MO, Battagello DS, Cardoso AR, Hauser DN, Bittencourt JC, Correa RG.Dopamine: Functions, signaling, and association with neurological diseases.Cell Mol Neurobiol. 2019;39(1):31-59. doi:10.1007/s10571-018-0632-3Albert PR, Vahid-Ansari F, Luckhart C.Serotonin-prefrontal cortical circuitry in anxiety and depression phenotypes: pivotal role of pre- and post-synaptic 5-HT1A receptor expression.Front Behav Neurosci. 2014;8:199. doi:10.3389/fnbeh.2014.00199Rajendran M, Dane E, Conley J, Tantama M.Imaging adenosine triphosphate (ATP).Biol Bull. 2016;231(1):73-84. doi:10.1086/689592Nowaczyk A, Kowalska M, Nowaczyk J, Grześk G.Carbon monoxide and nitric oxide as examples of the youngest class of transmitters.Int J Mol Sci. 2021;22(11):6029. doi:10.3390/ijms22116029National Center for Biotechnology Information. PubChem Database.Acetylcholine, CID=187.Berg KA, Clarke WP.Making sense of pharmacology: inverse agonism and functional selectivity.Int J Neuropsychopharmacol. 2018;21(10):962–977. doi:10.1093/ijnp/pyy071National Institute on Drug Abuse.The neurobiology of drug addiction.
Kuijpers M.Keeping synapses in shape: degradation pathways in the healthy and aging brain.Neuronal Signal. 2022;6(2):NS20210063. doi:10.1042/NS20210063
Ayano G.Common neurotransmitters: criteria for neurotransmitters, key locations, classifications and functions.Am J Psychiatry Neurosci. 2017;4(6):91-95.
Sukel K.Neurotransmission: neurotransmitters. The Dana Foundation.
Boto T, Tomchik SM.The excitatory, the inhibitory, and the modulatory: mapping chemical neurotransmission in the brain.Neuron. 2019;101(5):763-765. doi:10.1016/j.neuron.2019.02.021
Teleanu RI, Niculescu AG, Roza E, Vladâcenco O, Grumezescu AM, Teleanu DM.Neurotransmitters-Key factors in neurological and neurodegenerative disorders of the central nervous system.Int J Mol Sci. 2022;23(11):5954. doi:10.3390/ijms23115954
Valenzuela CF, Puglia MP, Zucca S.Focus on: neurotransmitter systems.Alcohol Res Health. 2011;34(1):106–120.
Wang R, Reddy PH.Role of glutamate and NMDA receptors in Alzheimer’s disease.J Alzheimers Dis. 2017;57(4):1041-1048. doi:10.3233/JAD-160763
Magon, N & Kalra, S.The orgasmic history of oxytocin: love, lust and labor.Indian J Endocrinol Metab. 2011;15:S156-S161. doi:10.4103/2230-8210.84851.
Schoenfeld TJ, Swanson C.A runner’s high for new neurons? Potential role for endorphins in exercise effects on adult neurogenesis.Biomolecules. 2021;11(8):1077. doi:10.3390/biom11081077
Tank AW, Lee wong D.Peripheral and central effects of circulating catecholamines.Compr Physiol. 2015;5(1):1-15. doi:10.1002/cphy.c140007
Nuutinen S, Panula P.Histamine in neurotransmission and brain diseases.Adv Exp Med Biol. 2010;709:95-107. doi:10.1007/978-1-4419-8056-4_10
Klein MO, Battagello DS, Cardoso AR, Hauser DN, Bittencourt JC, Correa RG.Dopamine: Functions, signaling, and association with neurological diseases.Cell Mol Neurobiol. 2019;39(1):31-59. doi:10.1007/s10571-018-0632-3
Albert PR, Vahid-Ansari F, Luckhart C.Serotonin-prefrontal cortical circuitry in anxiety and depression phenotypes: pivotal role of pre- and post-synaptic 5-HT1A receptor expression.Front Behav Neurosci. 2014;8:199. doi:10.3389/fnbeh.2014.00199
Rajendran M, Dane E, Conley J, Tantama M.Imaging adenosine triphosphate (ATP).Biol Bull. 2016;231(1):73-84. doi:10.1086/689592
Nowaczyk A, Kowalska M, Nowaczyk J, Grześk G.Carbon monoxide and nitric oxide as examples of the youngest class of transmitters.Int J Mol Sci. 2021;22(11):6029. doi:10.3390/ijms22116029
National Center for Biotechnology Information. PubChem Database.Acetylcholine, CID=187.
Berg KA, Clarke WP.Making sense of pharmacology: inverse agonism and functional selectivity.Int J Neuropsychopharmacol. 2018;21(10):962–977. doi:10.1093/ijnp/pyy071
National Institute on Drug Abuse.The neurobiology of drug addiction.
Kring, A M., Johnson, S L, Davison, GC, & Neale, J M.Abnormal Psychology. Hoboken, NJ: John Wiley & Sons; 2010.Verkhratsky, A & Krishtal, OA. Adenosine triphosphate (ATP) as a neurotransmitter. InEncyclopedia of Neuroscience, 4th Ed. Elsevier:115-123;2009.
Kring, A M., Johnson, S L, Davison, GC, & Neale, J M.Abnormal Psychology. Hoboken, NJ: John Wiley & Sons; 2010.
Verkhratsky, A & Krishtal, OA. Adenosine triphosphate (ATP) as a neurotransmitter. InEncyclopedia of Neuroscience, 4th Ed. Elsevier:115-123;2009.
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