A medication for opioid addiction may also help people suffering from depression.
or technically,
A role for the mu opioid receptor in the antidepressant effects of buprenorphine.
[See Original Abstract on Pubmed]
Authors of the study: Shivon A. Robinson, Rebecca L. Erickson, Caroline A. Browne, Irwin Lucki
Do you know someone frustrated by ineffective antidepressant treatment? Nearly one-third of patients with depression will not find relief with current antidepressant medication1. Creating new medications for depression is tricky, because we still do not completely understand what is happening in the brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals.. Furthermore, even if we developed a new antidepressant today, it would take over a decade for that medicine to become available to patients due to FDA regulations. To get around this issue, researchers are interested in finding new applications for drugs that have already been FDA approved for other illnesses. Repurposing an already-approved medication can greatly reduce the amount of time it takes for patients to receive effective treatment! Buprenorphine is a medication currently approved for the treatment of opioid addiction. Shivon Robinson, a neuroscience graduate student in Irwin Lucki’s lab, investigated whether buprenorphine could also be used to fight depression.
In her paper, Shivon demonstrated that buprenorphine reduced measures of depression in mice and she wanted to know how buprenorphine was having these effects. To assess depression-like symptoms in mice, she used what is called the “novelty-induced hypophagia” test, or NIH. NIH involves placing yummy treats (in this case, peanut butter chips) in the middle of an open, brightly lit chamber. Mice are generally wary of bright, open spaces so they will take some time to investigate the rest of the chamber before going to snack on the peanut butter chips. Conventional antidepressant medications will reduce the amount of time it takes for the mouse to approach the peanut butter chips, so other medications that do the same thing are thought to have similar effects as traditional antidepressants. She found that giving buprenorphine to mice before the test reduced the amount of time it took for the mice to approach the treats – just like current antidepressants!
After establishing that buprenorphine mimics traditional antidepressants in this task, Shivon wanted to know what buprenorphine was doing in the brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. to help reduce depression-like symptoms in mice. Drugs interact with the brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. by binding to receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron., which convey chemical messages to neuronsA nerve cell that uses electrical and chemical signals to send information to other cells including other neurons and muscles and other cells. There are many different types of receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron. produced by cells, and they only respond to specific drugs and molecules. When buprenorphine reaches the brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals., it binds to several types of receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron., two of which are kappa opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron. and mu opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron.. Shivon wondered if buprenorphine binding to one of these receptorA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron. types was important for the antidepressant effects they observed. She found that buprenorphine reduced depression-like behaviors in mice by binding to the mu opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron., not the kappa opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron.. She further validated this finding by using a different drug, cyprodime, that binds exclusively to mu opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron.. Cyprodime also reduced the amount of time it takes for mice to approach the peanut butter chips, supporting the idea that activation of mu opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron. by buprenorphine is important for antidepressant effects on this task.
This study represents an important step towards finding a potential new treatment for depression, an illness that affects nearly 7 million Americans annually. Depression is a disease that affects many different parts of the brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals.. Shivon’s work demonstrates that mu opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron. may play an important role in depression. Uncovering new ways that depression affects the brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. can help us find effective treatments for patients that fail to respond to current antidepressants.
In her paper, Shivon demonstrated that buprenorphine reduced measures of depression in mice and she wanted to know how buprenorphine was having these effects. To assess depression-like symptoms in mice, she used what is called the “novelty-induced hypophagia” test, or NIH. NIH involves placing yummy treats (in this case, peanut butter chips) in the middle of an open, brightly lit chamber. Mice are generally wary of bright, open spaces so they will take some time to investigate the rest of the chamber before going to snack on the peanut butter chips. Conventional antidepressant medications will reduce the amount of time it takes for the mouse to approach the peanut butter chips, so other medications that do the same thing are thought to have similar effects as traditional antidepressants. She found that giving buprenorphine to mice before the test reduced the amount of time it took for the mice to approach the treats – just like current antidepressants!
After establishing that buprenorphine mimics traditional antidepressants in this task, Shivon wanted to know what buprenorphine was doing in the brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. to help reduce depression-like symptoms in mice. Drugs interact with the brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. by binding to receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron., which convey chemical messages to neuronsA nerve cell that uses electrical and chemical signals to send information to other cells including other neurons and muscles and other cells. There are many different types of receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron. produced by cells, and they only respond to specific drugs and molecules. When buprenorphine reaches the brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals., it binds to several types of receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron., two of which are kappa opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron. and mu opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron.. Shivon wondered if buprenorphine binding to one of these receptorA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron. types was important for the antidepressant effects they observed. She found that buprenorphine reduced depression-like behaviors in mice by binding to the mu opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron., not the kappa opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron.. She further validated this finding by using a different drug, cyprodime, that binds exclusively to mu opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron.. Cyprodime also reduced the amount of time it takes for mice to approach the peanut butter chips, supporting the idea that activation of mu opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron. by buprenorphine is important for antidepressant effects on this task.
This study represents an important step towards finding a potential new treatment for depression, an illness that affects nearly 7 million Americans annually. Depression is a disease that affects many different parts of the brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals.. Shivon’s work demonstrates that mu opioid receptorsA molecule that binds to a chemical signal and causes a change inside a cell. For example, a receptor on the outside of a neuron can bind to a neurotransmitter released from a different neuron. may play an important role in depression. Uncovering new ways that depression affects the brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. can help us find effective treatments for patients that fail to respond to current antidepressants.
Meet the brief writer: Lexi Ellis
Citations:
Ionescu DF, Rosenbaum JF, Alpert JE. Pharmacological approaches to the challenge of treatment-resistant depression. Dialogues Clin Neurosci. 2015;17(2):111–126.