Neuroscience

Articles and news from the latest research reports.

Posts tagged brain

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Follow-up study finds lasting benefit from MDMA for people with PTSD
The follow-up study was based on an original trial held in 2010 where 20 patients suffering from long term PTSD were given MDMA (the main ingredient in the party drug ecstasy) as part of their psychotherapy sessions. The researchers reported at the time that 83% of the participants showed improvements in their condition two months later.
In this new work, the researchers revisited the original patients three and a half years later (one refused to participate leaving just 19) to see how well they were doing. They found that just two of the patients had suffered a relapse – the rest they say maintained the relief they had found in the original trial.
The research was sponsored by the group Multidisciplinary Association for Psychedelic Studies (MAPS), whose mission is to seek out treatments for a variety of mental ailments using non-traditional drug therapies. In addition to providing funds for the trials they also worked out agreements with the government to allow for legal testing of the drug (it currently has as a Schedule I status.)
Study leads Michael and Ann Mithoefer conducted the original trial out of their private practice office. Each trial was conducted with a single patient at a time and involved a non-pharmaceutical therapy session followed by one where the patient was given a dose of MDMA. Another traditional session was held later – the sessions that included use of the drug lasted up to eight hours because the effects of the drugs last that long.
The researchers believe that MDMA helps PTSD sufferers by allowing them to relive the emotionally traumatic experience that led to their condition in a more relaxed and receptive way. Because of the promising results, MAPS is calling on the government to relax its rules on the testing and use of MDMA for medical applications.

Follow-up study finds lasting benefit from MDMA for people with PTSD

The follow-up study was based on an original trial held in 2010 where 20 patients suffering from long term PTSD were given MDMA (the main ingredient in the party drug ecstasy) as part of their psychotherapy sessions. The researchers reported at the time that 83% of the participants showed improvements in their condition two months later.

In this new work, the researchers revisited the original patients three and a half years later (one refused to participate leaving just 19) to see how well they were doing. They found that just two of the patients had suffered a relapse – the rest they say maintained the relief they had found in the original trial.

The research was sponsored by the group Multidisciplinary Association for Psychedelic Studies (MAPS), whose mission is to seek out treatments for a variety of mental ailments using non-traditional drug therapies. In addition to providing funds for the trials they also worked out agreements with the government to allow for legal testing of the drug (it currently has as a Schedule I status.)

Study leads Michael and Ann Mithoefer conducted the original trial out of their private practice office. Each trial was conducted with a single patient at a time and involved a non-pharmaceutical therapy session followed by one where the patient was given a dose of MDMA. Another traditional session was held later – the sessions that included use of the drug lasted up to eight hours because the effects of the drugs last that long.

The researchers believe that MDMA helps PTSD sufferers by allowing them to relive the emotionally traumatic experience that led to their condition in a more relaxed and receptive way. Because of the promising results, MAPS is calling on the government to relax its rules on the testing and use of MDMA for medical applications.

Filed under PTSD MDMA brain study neuroscience psychology science

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Brain waves encode rules for behavior
One of the biggest puzzles in neuroscience is how our brains encode thoughts, such as perceptions and memories, at the cellular level. Some evidence suggests that ensembles of neurons represent each unique piece of information, but no one knows just what these ensembles look like, or how they form.
A new study from researchers at MIT and Boston University (BU) sheds light on how neural ensembles form thoughts and support the flexibility to change one’s mind. The research team, led by Earl Miller, the Picower Professor of Neuroscience at MIT, identified groups of neurons that encode specific behavioral rules by oscillating in synchrony with each other.
The results suggest that the nature of conscious thought may be rhythmic, according to the researchers, who published their findings in the Nov. 21 issue of Neuron.
“As we talk, thoughts float in and out of our heads. Those are all ensembles forming and then reconfiguring to something else. It’s been a mystery how the brain does this,” says Miller, who is also a member of MIT’s Picower Institute for Learning and Memory. “That’s the fundamental problem that we’re talking about — the very nature of thought itself.”

Brain waves encode rules for behavior

One of the biggest puzzles in neuroscience is how our brains encode thoughts, such as perceptions and memories, at the cellular level. Some evidence suggests that ensembles of neurons represent each unique piece of information, but no one knows just what these ensembles look like, or how they form.

A new study from researchers at MIT and Boston University (BU) sheds light on how neural ensembles form thoughts and support the flexibility to change one’s mind. The research team, led by Earl Miller, the Picower Professor of Neuroscience at MIT, identified groups of neurons that encode specific behavioral rules by oscillating in synchrony with each other.

The results suggest that the nature of conscious thought may be rhythmic, according to the researchers, who published their findings in the Nov. 21 issue of Neuron.

“As we talk, thoughts float in and out of our heads. Those are all ensembles forming and then reconfiguring to something else. It’s been a mystery how the brain does this,” says Miller, who is also a member of MIT’s Picower Institute for Learning and Memory. “That’s the fundamental problem that we’re talking about — the very nature of thought itself.”

Filed under brain brainwaves neural oscillations learning memory perception neuroscience psychology science

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An antidote for hypersomnia
Researchers at Emory University School of Medicine have discovered that dozens of adults with an elevated need for sleep have a substance in their cerebrospinal fluid that acts like a sleeping pill.
The results are scheduled for publication online Wednesday by the journal Science Translational Medicine.
Some members of this patient population appear to have a distinct, disabling sleep disorder called “primary hypersomnia,” which is separate from better-known conditions such as sleep apnea or narcolepsy. They regularly sleep more than 70 hours per week and have difficulties awakening. When awake, they still have reaction times comparable to someone who has been awake all night. Their sleepiness often interferes with work or school attendance, and conventional treatments such as stimulants bring little relief.
"These individuals report feeling as if they’re walking around in a fog — physically, but not mentally awake," says lead author David Rye, professor of neurology at Emory University School of Medicine and director of research for Emory Healthcare’s Program in Sleep. "When encountering excessive sleepiness in a patient, we typically think it’s caused by an impairment in the brain’s wake systems and treat it with stimulant medications. However, in these patients, the situation is more akin to attempting to drive a car with the parking brake engaged. Our thinking needs to shift from pushing the accelerator harder, to releasing the brake."
In a clinical study with seven patients who remained sleepy despite above-ordinary sleep amounts and treatment with stimulants, Emory researchers showed that treatment with the drug flumazenil can restore alertness, although flumazenil’s effectiveness was not uniform for all seven. Alertness was gauged through the psychomotor vigilance test, a measurement of reaction time.

An antidote for hypersomnia

Researchers at Emory University School of Medicine have discovered that dozens of adults with an elevated need for sleep have a substance in their cerebrospinal fluid that acts like a sleeping pill.

The results are scheduled for publication online Wednesday by the journal Science Translational Medicine.

Some members of this patient population appear to have a distinct, disabling sleep disorder called “primary hypersomnia,” which is separate from better-known conditions such as sleep apnea or narcolepsy. They regularly sleep more than 70 hours per week and have difficulties awakening. When awake, they still have reaction times comparable to someone who has been awake all night. Their sleepiness often interferes with work or school attendance, and conventional treatments such as stimulants bring little relief.

"These individuals report feeling as if they’re walking around in a fog — physically, but not mentally awake," says lead author David Rye, professor of neurology at Emory University School of Medicine and director of research for Emory Healthcare’s Program in Sleep. "When encountering excessive sleepiness in a patient, we typically think it’s caused by an impairment in the brain’s wake systems and treat it with stimulant medications. However, in these patients, the situation is more akin to attempting to drive a car with the parking brake engaged. Our thinking needs to shift from pushing the accelerator harder, to releasing the brake."

In a clinical study with seven patients who remained sleepy despite above-ordinary sleep amounts and treatment with stimulants, Emory researchers showed that treatment with the drug flumazenil can restore alertness, although flumazenil’s effectiveness was not uniform for all seven. Alertness was gauged through the psychomotor vigilance test, a measurement of reaction time.

Filed under brain sleep hypersomnia narcolepsy neuroscience medicine science

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Fetuses yawn in the womb, according to new research
We know that unborn babies hiccup, swallow and stretch in the womb but new observational research concludes that they also yawn.
The 4D scans of 15 healthy fetuses, by Durham and Lancaster Universities, also suggest that yawning is a developmental process which could potentially give doctors another index of a fetus’ health.
While some researchers have suggested that fetuses yawn, others have disagreed and claim it is simple mouth opening.
But the new research clearly distinguished ‘yawning’ from ‘non-yawn mouth opening’ based on the duration of mouth opening. The researchers did this by using the 4D video footage to closely examine all events where a mouth stretch occurred in the fetus.
Using their newly developed criteria, the research team found that over half of the mouth openings observed in the study were classed as yawns.
The study was carried out on eight female and seven male foetuses from 24 to 36 weeks gestation. The researchers found that yawning declined from 28 weeks and that there was no significant difference between boys and girls in yawning frequency.
Although the function and importance of yawning is still unknown, the study findings suggest that yawning could be linked to fetal development, and as such could provide a further medical indication of the health of the unborn baby.

Fetuses yawn in the womb, according to new research

We know that unborn babies hiccup, swallow and stretch in the womb but new observational research concludes that they also yawn.

The 4D scans of 15 healthy fetuses, by Durham and Lancaster Universities, also suggest that yawning is a developmental process which could potentially give doctors another index of a fetus’ health.

While some researchers have suggested that fetuses yawn, others have disagreed and claim it is simple mouth opening.

But the new research clearly distinguished ‘yawning’ from ‘non-yawn mouth opening’ based on the duration of mouth opening. The researchers did this by using the 4D video footage to closely examine all events where a mouth stretch occurred in the fetus.

Using their newly developed criteria, the research team found that over half of the mouth openings observed in the study were classed as yawns.

The study was carried out on eight female and seven male foetuses from 24 to 36 weeks gestation. The researchers found that yawning declined from 28 weeks and that there was no significant difference between boys and girls in yawning frequency.

Although the function and importance of yawning is still unknown, the study findings suggest that yawning could be linked to fetal development, and as such could provide a further medical indication of the health of the unborn baby.

Filed under brain brain maturation brain development fetus yawning psychology neuroscience science

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MRI shows brain disruption in patients with post-concussion syndrome

MRI shows changes in the brains of people with post-concussion syndrome (PCS), according to a new study published online in the journal Radiology. Researchers hope the results point the way to improved detection and treatment for the disorder.

PCS affects approximately 20 percent to 30 percent of people who suffer mild traumatic brain injury (MTBI)—defined by the World Health Organization as a traumatic event causing brief loss of consciousness and/or transient memory dysfunction or disorientation. Symptoms of PCS include headache, poor concentration and memory difficulty.

Conventional neuroimaging cannot distinguish which MTBI patients will develop PCS.

"Conventional imaging with CT or MRI is pretty much normal in MTBI patients, even though some go on to develop symptoms, including severe cognitive problems," said Yulin Ge, M.D., associate professor, Department of Radiology at the NYU School of Medicine in New York City. "We want to try to better understand why and how these symptoms arise."

Dr. Ge’s study used MRI to look at the brain during its resting state, or the state when it is not engaged in a specific task, such as when the mind wanders or while daydreaming. The resting state is thought to involve connections among a number of regions, with the default mode network (DMN) playing a particularly important role.

"Baseline DMN is very important for information processing and maintenance," Dr. Ge said.

Alterations in DMN have been found in several psychiatric disorders, including Alzheimer’s disease, autism and schizophrenia, but little is known about DMN connectivity changes in MTBI.

For the new study, Dr. Ge and colleagues used resting-state functional MRI to compare 23 MTBI patients who had post-traumatic symptoms within two months of the injury and 18 age-matched healthy controls. Resting state MRI detects distinct changes in baseline oxygen level fluctuations associated with brain functional networks between patients with MTBI and control patients.

The MRI results showed that communication and information integration in the brain were disrupted among key DMN structures after mild head injury, and that the brain tapped into different neural resources to compensate for the impaired function.

"We found decreased functional connectivity in the posterior network of the brain and increased connectivity in the anterior component, probably due to functional compensation in patients with PCS," Dr. Ge said. "The reduced posterior connectivity correlated positively with neurocognitive dysfunction."

Dr. Ge and the other researchers hope to recruit additional MTBI patients for further studies with an eye toward developing a biomarker to monitor disease progression and recovery as well as treatment effects.

"We want to do studies to look at the changes in the network over time and correlate these functional changes with structural changes in the brain," he said. "This could give us hints on treatments to bring back cognitive function."

(Source: medicalxpress.com)

Filed under post-concussion syndrome TBI neuroimaging cognitive function brain neuroscience psychology science

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Researchers find decline in availability and use of key treatment for depression
Electroconvulsive therapy (ECT) is considered the most effective treatment option for patients with severe depression who cannot find symptom relief through antidepressant medications or psychotherapy. In a new study, researchers at Butler Hospital and Bradley Hospital in Rhode Island found a sharp decline in the availability and use of ECT in general hospitals across the U.S. The findings were published online in the journal Biological Psychiatry on October 10, 2012.
The researchers analyzed data from a nationally representative survey of US general hospitals, the Nationwide Inpatient Sample (NIS), conducted annually by the Agency for Healthcare Research and Quality (AHRQ). They took information from between five and eight million patient discharge records at 1,000 hospitals nationwide between the years 1993 through 2009 and found that the annual number of hospital stays in which ECT was administered fell 43 percent over the 17 year period, from more than 1.2 million to 720,000. Researchers also found a dramatic decline in the percentage of hospitals conducting ECT, from 55 percent to 35 percent of facilities with a psychiatric unit. The percentage of inpatients with severe, recurrent major depression treated in hospitals conducting ECT fell from 71 to 45 percent. But for depressed patients treated in hospitals that conduct ECT, the proportion who received the procedure remained stable.
"The data strongly support the impression that psychiatric units in general hospitals are discontinuing use of ECT and that this is driving the decline in the number of severely depressed inpatients receiving the procedure," said Brady Case, MD, an assistant professor of psychiatry and human behavior at Brown University and director of the Health Services Research Program at Bradley Hospital. "Growing pressures to avoid the inpatient treatment costs and length of stay associated with ECT may be one factor associated with this trend. We didn’t have information on provider and patient attitudes, but as facilities cease conducting ECT, we can expect that fewer clinicians and inpatients are exposed to the option, reinforcing the turn away from ECT." Researchers also note the FDA approval of new treatment alternatives, like vagus nerve stimulation and transcranial magnetic stimulation, as possible influences.

Researchers find decline in availability and use of key treatment for depression

Electroconvulsive therapy (ECT) is considered the most effective treatment option for patients with severe depression who cannot find symptom relief through antidepressant medications or psychotherapy. In a new study, researchers at Butler Hospital and Bradley Hospital in Rhode Island found a sharp decline in the availability and use of ECT in general hospitals across the U.S. The findings were published online in the journal Biological Psychiatry on October 10, 2012.

The researchers analyzed data from a nationally representative survey of US general hospitals, the Nationwide Inpatient Sample (NIS), conducted annually by the Agency for Healthcare Research and Quality (AHRQ). They took information from between five and eight million patient discharge records at 1,000 hospitals nationwide between the years 1993 through 2009 and found that the annual number of hospital stays in which ECT was administered fell 43 percent over the 17 year period, from more than 1.2 million to 720,000. Researchers also found a dramatic decline in the percentage of hospitals conducting ECT, from 55 percent to 35 percent of facilities with a psychiatric unit. The percentage of inpatients with severe, recurrent major depression treated in hospitals conducting ECT fell from 71 to 45 percent. But for depressed patients treated in hospitals that conduct ECT, the proportion who received the procedure remained stable.

"The data strongly support the impression that psychiatric units in general hospitals are discontinuing use of ECT and that this is driving the decline in the number of severely depressed inpatients receiving the procedure," said Brady Case, MD, an assistant professor of psychiatry and human behavior at Brown University and director of the Health Services Research Program at Bradley Hospital. "Growing pressures to avoid the inpatient treatment costs and length of stay associated with ECT may be one factor associated with this trend. We didn’t have information on provider and patient attitudes, but as facilities cease conducting ECT, we can expect that fewer clinicians and inpatients are exposed to the option, reinforcing the turn away from ECT." Researchers also note the FDA approval of new treatment alternatives, like vagus nerve stimulation and transcranial magnetic stimulation, as possible influences.

Filed under brain depression electroconvulsive therapy ECT neuroscience psychology science

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Optical Illusions Show How We See
Imagine… as you wake later than usual rolling over towards the window, you notice that it’s a gorgeous day outside. Warm, yellow sunlight shines in through glass illuminating floating “dust angles.” On the other side of the glass, past the oak tree with yellowing leaves, you see a brilliant blue sky. For the first time it occurs to you that a blue sky is a contradiction: the sky at night is devoid of color, so why during the day does the world seem to be shrouded in a blanket of blue? Years previously as a child full of questions you asked your parents, but the answer they offered seemed somehow inadequate at the time… less than magical. And so the question remains… as it does the most of us.
The answer is this: The sky isn’t actually colored at all (not blue or yellow or red or green). Rather, it’s your mind that’s colored. The world around us is physics devoid of meaning, whereas our perception of the world is meaning devoid of physics. In terms of physics, the light in the sky is heavily biased towards smaller wavelengths (around 450 nanometers). This is because the air itself scatters smaller wavelengths of light more than it does larger ones. Which means the air in the sky is like a filter, letting primarily medium to long wavelengths through more easily than short wavelengths. Hence why the sky is composed primarily of shorter wavelengths (and so appears bluish), whereas the light from sun is composed primarily of longer wavelengths (and so appears more reddish). While the differential scattering of sunlight by the air explains the non-uniform distribution of wavelengths across the sky, it doesn’t explain why shorter wavelengths are seen as blue and the longer ones as red.

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Optical Illusions Show How We See

Imagine… as you wake later than usual rolling over towards the window, you notice that it’s a gorgeous day outside. Warm, yellow sunlight shines in through glass illuminating floating “dust angles.” On the other side of the glass, past the oak tree with yellowing leaves, you see a brilliant blue sky. For the first time it occurs to you that a blue sky is a contradiction: the sky at night is devoid of color, so why during the day does the world seem to be shrouded in a blanket of blue? Years previously as a child full of questions you asked your parents, but the answer they offered seemed somehow inadequate at the time… less than magical. And so the question remains… as it does the most of us.

The answer is this: The sky isn’t actually colored at all (not blue or yellow or red or green). Rather, it’s your mind that’s colored. The world around us is physics devoid of meaning, whereas our perception of the world is meaning devoid of physics. In terms of physics, the light in the sky is heavily biased towards smaller wavelengths (around 450 nanometers). This is because the air itself scatters smaller wavelengths of light more than it does larger ones. Which means the air in the sky is like a filter, letting primarily medium to long wavelengths through more easily than short wavelengths. Hence why the sky is composed primarily of shorter wavelengths (and so appears bluish), whereas the light from sun is composed primarily of longer wavelengths (and so appears more reddish). While the differential scattering of sunlight by the air explains the non-uniform distribution of wavelengths across the sky, it doesn’t explain why shorter wavelengths are seen as blue and the longer ones as red.

Read more

Filed under brain optical illusions perception neuroscience psychology science

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Scripps Research Institute Team Identifies a Potential Cause of Parkinson’s Disease that May Lead to New Treatment Options

Deciphering what causes the brain cell degeneration of Parkinson’s disease has remained a perplexing challenge for scientists. But a team led by scientists from The Scripps Research Institute (TSRI) has pinpointed a key factor controlling damage to brain cells in a mouse model of Parkinson’s disease. The discovery could lead to new targets for Parkinson’s that may be useful in preventing the actual condition.

The team, led by TSRI neuroscientist Bruno Conti, describes the work in a paper published online ahead of print on November 19, 2012 by the Journal of Immunology.

Parkinson’s disease plagues about one percent of people over 60 years old, as well as some younger patients. The disease is characterized by the loss of dopamine-producing neurons primarily in the substantia nigra pars compacta, a region of the brain regulating movements and coordination.

Among the known causes of Parkinson’s disease are several genes and some toxins. However, the majority of Parkinson’s disease cases remain of unknown origin, leading researchers to believe the disease may result from a combination of genetics and environmental factors.

Neuroinflammation and its mediators have recently been proposed to contribute to neuronal loss in Parkinson’s, but how these factors could preferentially damage dopaminergic neurons has remained unclear until now.

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Filed under brain brain cells parkinson parkinson's disease dopamine neurodegeneration neuroscience science

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A 3-D Light Switch for the Brain
A new tool for neuroscientists delivers a thousand pinpricks of light to a chunk of gray matter smaller than a sugar cube. The new fiber-optic device, created by biologists and engineers at the Massachusetts Institute of Technology (MIT) in Cambridge, is the first tool that can deliver precise points of light to a 3-D section of living brain tissue. The work is a step forward for a relatively new but promising technique that uses gene therapy to turn individual brain cells on and off with light.
Scientists can use the new 3-D “light switch” to better understand how the brain works. It might also be used one day to create neural prostheses that could treat conditions such as Parkinson’s disease and epilepsy. The researchers describe their device in a paper published today in the Optical Society’s (OSA) journal Optics Letters.
The technique of manipulating neurons with light is only a few years old, but the authors estimate that thousands of scientists are already using this technology, called optogenetics, to study the brain. In optogenetics, researchers first sensitize select cells in the brain to a particular color of light. Then, by illuminating precise areas of the brain, they are able to selectively activate or deactivate the individual neurons that have been sensitized.
Ed Boyden, a synthetic biologist at MIT and co-lead researcher on the paper, is a pioneer of this emerging field, which he says offers the ability to probe connections in the brain.
"You can see neural activity in the brain that is associated with specific behaviors," Boyden says, “but is it important? Or is it a passive copy of important activity located elsewhere in the brain? There’s no way to know for sure if you just watch.” Optogenetics allows scientists to play a more active role in probing the brain’s connections, to fire up one type of cell or deactivate another and then observe the effect on a behavior, such as quieting a seizure.
Unlike the previous, 1-D versions of this light-emitting device, the new tool delivers light to the brain in three dimensions, opening the potential to explore entire circuits within the brain. So far, the 3-D version has been tested in mice, although Boyden and colleagues have used earlier optogenetic technologies with non-human primates as well.

A 3-D Light Switch for the Brain

A new tool for neuroscientists delivers a thousand pinpricks of light to a chunk of gray matter smaller than a sugar cube. The new fiber-optic device, created by biologists and engineers at the Massachusetts Institute of Technology (MIT) in Cambridge, is the first tool that can deliver precise points of light to a 3-D section of living brain tissue. The work is a step forward for a relatively new but promising technique that uses gene therapy to turn individual brain cells on and off with light.

Scientists can use the new 3-D “light switch” to better understand how the brain works. It might also be used one day to create neural prostheses that could treat conditions such as Parkinson’s disease and epilepsy. The researchers describe their device in a paper published today in the Optical Society’s (OSA) journal Optics Letters.

The technique of manipulating neurons with light is only a few years old, but the authors estimate that thousands of scientists are already using this technology, called optogenetics, to study the brain. In optogenetics, researchers first sensitize select cells in the brain to a particular color of light. Then, by illuminating precise areas of the brain, they are able to selectively activate or deactivate the individual neurons that have been sensitized.

Ed Boyden, a synthetic biologist at MIT and co-lead researcher on the paper, is a pioneer of this emerging field, which he says offers the ability to probe connections in the brain.

"You can see neural activity in the brain that is associated with specific behaviors," Boyden says, “but is it important? Or is it a passive copy of important activity located elsewhere in the brain? There’s no way to know for sure if you just watch.” Optogenetics allows scientists to play a more active role in probing the brain’s connections, to fire up one type of cell or deactivate another and then observe the effect on a behavior, such as quieting a seizure.

Unlike the previous, 1-D versions of this light-emitting device, the new tool delivers light to the brain in three dimensions, opening the potential to explore entire circuits within the brain. So far, the 3-D version has been tested in mice, although Boyden and colleagues have used earlier optogenetic technologies with non-human primates as well.

Filed under brain brain tissue fiber-optic device neuron optogenetics neural activity neuroscience science

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