neurosciencestuff:

Study reveals how ecstasy acts on the brain and hints at therapeutic uses
Brain imaging experiments have revealed for the first time how ecstasy produces feelings of euphoria in users.
Results of the study at Imperial College London, parts of which were televised in Drugs Live on Channel 4 in 2012, have now been published in the journal Biological Psychiatry.
The findings hint at ways that ecstasy, or MDMA, might be useful in the treatment of anxiety and post-traumatic stress disorder (PTSD).
MDMA has been a popular recreational drug since the 1980s, but there has been little research on which areas of the brain it affects. The new study is the first to use functional magnetic resonance imaging (fMRI) on resting subjects under its influence.
Twenty-five volunteers underwent brain scans on two occasions, one after taking the drug and one after taking a placebo, without knowing which they had been given.
The results show that MDMA decreases activity in the limbic system – a set of structures involved in emotional responses. These effects were stronger in subjects who reported stronger subjective experiences, suggesting that they are related.
Communication between the medial temporal lobe and medial prefrontal cortex, which is involved in emotional control, was reduced. This effect, and the drop in activity in the limbic system, are opposite to patterns seen in patients who suffer from anxiety.
MDMA also increased communication between the amygdala and the hippocampus. Studies on patients with PTSD have found a reduction in communication between these areas.
The project was led by David Nutt, the Edmond J. Safra Professor of Neuropsychopharmacology at Imperial College London, and Professor Val Curran at UCL.
Dr Robin Carhart-Harris from the Department of Medicine at Imperial, who performed the research, said: “We found that MDMA caused reduced blood flow in regions of the brain linked to emotion and memory. These effects may be related to the feelings of euphoria that people experience on the drug.”
Professor Nutt added: “The findings suggest possible clinical uses of MDMA in treating anxiety and PTSD, but we need to be careful about drawing too many conclusions from a study in healthy volunteers. We would have to do studies in patients to see if we find the same effects.”
MDMA has been investigated as an adjunct to psychotherapy in the treatment of PTSD, with a recent pilot study in the US reporting positive preliminary results.
As part of the Imperial study, the volunteers were asked to recall their favourite and worst memories while inside the scanner. They rated their favourite memories as more vivid, emotionally intense and positive after MDMA than placebo, and they rated their worst memories less negatively. This was reflected in the way that parts of the brain were activated more or less strongly under MDMA. These results were published in the International Journal of Neuropsychopharmacology.
Dr Carhart-Harris said: “In healthy volunteers, MDMA seems to lessen the impact of painful memories. This fits with the idea that it could help patients with PTSD revisit their traumatic experiences in psychotherapy without being overwhelmed by negative emotions, but we need to do studies in PTSD patients to see if the drug affects them in the same way.”

neurosciencestuff:

Study reveals how ecstasy acts on the brain and hints at therapeutic uses

Brain imaging experiments have revealed for the first time how ecstasy produces feelings of euphoria in users.

Results of the study at Imperial College London, parts of which were televised in Drugs Live on Channel 4 in 2012, have now been published in the journal Biological Psychiatry.

The findings hint at ways that ecstasy, or MDMA, might be useful in the treatment of anxiety and post-traumatic stress disorder (PTSD).

MDMA has been a popular recreational drug since the 1980s, but there has been little research on which areas of the brain it affects. The new study is the first to use functional magnetic resonance imaging (fMRI) on resting subjects under its influence.

Twenty-five volunteers underwent brain scans on two occasions, one after taking the drug and one after taking a placebo, without knowing which they had been given.

The results show that MDMA decreases activity in the limbic system – a set of structures involved in emotional responses. These effects were stronger in subjects who reported stronger subjective experiences, suggesting that they are related.

Communication between the medial temporal lobe and medial prefrontal cortex, which is involved in emotional control, was reduced. This effect, and the drop in activity in the limbic system, are opposite to patterns seen in patients who suffer from anxiety.

MDMA also increased communication between the amygdala and the hippocampus. Studies on patients with PTSD have found a reduction in communication between these areas.

The project was led by David Nutt, the Edmond J. Safra Professor of Neuropsychopharmacology at Imperial College London, and Professor Val Curran at UCL.

Dr Robin Carhart-Harris from the Department of Medicine at Imperial, who performed the research, said: “We found that MDMA caused reduced blood flow in regions of the brain linked to emotion and memory. These effects may be related to the feelings of euphoria that people experience on the drug.”

Professor Nutt added: “The findings suggest possible clinical uses of MDMA in treating anxiety and PTSD, but we need to be careful about drawing too many conclusions from a study in healthy volunteers. We would have to do studies in patients to see if we find the same effects.”

MDMA has been investigated as an adjunct to psychotherapy in the treatment of PTSD, with a recent pilot study in the US reporting positive preliminary results.

As part of the Imperial study, the volunteers were asked to recall their favourite and worst memories while inside the scanner. They rated their favourite memories as more vivid, emotionally intense and positive after MDMA than placebo, and they rated their worst memories less negatively. This was reflected in the way that parts of the brain were activated more or less strongly under MDMA. These results were published in the International Journal of Neuropsychopharmacology.

Dr Carhart-Harris said: “In healthy volunteers, MDMA seems to lessen the impact of painful memories. This fits with the idea that it could help patients with PTSD revisit their traumatic experiences in psychotherapy without being overwhelmed by negative emotions, but we need to do studies in PTSD patients to see if the drug affects them in the same way.”

thenewenlightenmentage:

Neuroscientists Pinpoint Location of Fear Memory in Amygdala
Jan. 27, 2013 — A rustle of undergrowth in the outback: it’s a sound that might make an animal or person stop sharply and be still, in the anticipation of a predator. That “freezing” is part of the fear response, a reaction to a stimulus in the environment and part of the brain’s determination of whether to be afraid of it.
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thenewenlightenmentage:

Neuroscientists Pinpoint Location of Fear Memory in Amygdala

Jan. 27, 2013 — A rustle of undergrowth in the outback: it’s a sound that might make an animal or person stop sharply and be still, in the anticipation of a predator. That “freezing” is part of the fear response, a reaction to a stimulus in the environment and part of the brain’s determination of whether to be afraid of it.

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neurosciencestuff:

Discovery sheds new light on marijuana’s anxiety relief effects
An international group led by Vanderbilt University researchers has found cannabinoid receptors, through which marijuana exerts its effects, in a key emotional hub in the brain involved in regulating anxiety and the flight-or-fight response.
This is the first time cannabinoid receptors have been identified in the central nucleus of the amygdala in a mouse model, they report in the current issue of the journal Neuron.
The discovery may help explain why marijuana users say they take the drug mainly to reduce anxiety, said Sachin Patel, M.D., Ph.D., the paper’s senior author and professor of Psychiatry and of Molecular Physiology and Biophysics.
Led by first author Teniel Ramikie, a graduate student in Patel’s lab, the researchers also showed for the first time how nerve cells in this part of the brain make and release their own natural “endocannabinoids.”
The study “could be highly important for understanding how cannabis exerts its behavioral effects,” Patel said. As the legalization of marijuana spreads across the country, more people — and especially young people whose brains are still developing — are being exposed to the drug. Previous studies at Vanderbilt and elsewhere, Patel said, have suggested the following:
• The natural endocannabinoid system regulates anxiety and the response to stress by dampening excitatory signals that involve the neurotransmitter glutamate.
• Chronic stress or acute, severe emotional trauma can cause a reduction in both the production of endocannabinoids and the responsiveness of the receptors. Without their “buffering” effect, anxiety goes up.
• While marijuana’s “exogenous” cannabinoids also can reduce anxiety, chronic use of the drug down-regulates the receptors, paradoxically increasing anxiety. This can trigger “a vicious cycle” of increasing marijuana use that in some cases leads to addiction.
In the current study, the researchers used high-affinity antibodies to “label” the cannabinoid receptors so they could be seen using various microscopy techniques, including electron microscopy, which allowed very detailed visualization at individual synapses, or gaps between nerve cells.
“We know where the receptors are, we know their function, we know how these neurons make their own cannabinoids,” Patel said. “Now can we see how that system is affected by … stress and chronic (marijuana) use? It might fundamentally change our understanding of cellular communication in the amygdala.”
(Image: Shutterstock)

neurosciencestuff:

Discovery sheds new light on marijuana’s anxiety relief effects

An international group led by Vanderbilt University researchers has found cannabinoid receptors, through which marijuana exerts its effects, in a key emotional hub in the brain involved in regulating anxiety and the flight-or-fight response.

This is the first time cannabinoid receptors have been identified in the central nucleus of the amygdala in a mouse model, they report in the current issue of the journal Neuron.

The discovery may help explain why marijuana users say they take the drug mainly to reduce anxiety, said Sachin Patel, M.D., Ph.D., the paper’s senior author and professor of Psychiatry and of Molecular Physiology and Biophysics.

Led by first author Teniel Ramikie, a graduate student in Patel’s lab, the researchers also showed for the first time how nerve cells in this part of the brain make and release their own natural “endocannabinoids.”

The study “could be highly important for understanding how cannabis exerts its behavioral effects,” Patel said. As the legalization of marijuana spreads across the country, more people — and especially young people whose brains are still developing — are being exposed to the drug.
Previous studies at Vanderbilt and elsewhere, Patel said, have suggested the following:

• The natural endocannabinoid system regulates anxiety and the response to stress by dampening excitatory signals that involve the neurotransmitter glutamate.

• Chronic stress or acute, severe emotional trauma can cause a reduction in both the production of endocannabinoids and the responsiveness of the receptors. Without their “buffering” effect, anxiety goes up.

• While marijuana’s “exogenous” cannabinoids also can reduce anxiety, chronic use of the drug down-regulates the receptors, paradoxically increasing anxiety. This can trigger “a vicious cycle” of increasing marijuana use that in some cases leads to addiction.

In the current study, the researchers used high-affinity antibodies to “label” the cannabinoid receptors so they could be seen using various microscopy techniques, including electron microscopy, which allowed very detailed visualization at individual synapses, or gaps between nerve cells.

“We know where the receptors are, we know their function, we know how these neurons make their own cannabinoids,” Patel said. “Now can we see how that system is affected by … stress and chronic (marijuana) use? It might fundamentally change our understanding of cellular communication in the amygdala.”

(Image: Shutterstock)

thenewenlightenmentage:

Scientists Discover a New Pathway for Fear Deep Within the Brain
‘Far-reaching’ neurons connect the amygdala with fear response center to control behavior.
Fear is primal. In the wild, it serves as a protective mechanism, allowing animals to avoid predators or other perceived threats. For humans, fear is much more complex. A normal amount keeps us safe from danger. But in extreme cases, like post-traumatic stress disorder (PTSD), too much fear can prevent people from living healthy, productive lives. Researchers are actively working to understand how the brain translates fear into action. Today, scientists at Cold Spring Harbor Laboratory (CSHL) announce the discovery of a new neural circuit in the brain that directly links the site of fear memory with an area of the brainstem that controls behavior.
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thenewenlightenmentage:

Scientists Discover a New Pathway for Fear Deep Within the Brain

‘Far-reaching’ neurons connect the amygdala with fear response center to control behavior.

Fear is primal. In the wild, it serves as a protective mechanism, allowing animals to avoid predators or other perceived threats. For humans, fear is much more complex. A normal amount keeps us safe from danger. But in extreme cases, like post-traumatic stress disorder (PTSD), too much fear can prevent people from living healthy, productive lives. Researchers are actively working to understand how the brain translates fear into action. Today, scientists at Cold Spring Harbor Laboratory (CSHL) announce the discovery of a new neural circuit in the brain that directly links the site of fear memory with an area of the brainstem that controls behavior.

Continue Reading

neuromorphogenesis:

In mapping feat, scientists pinpoint neurons where select memories grow
Memories are difficult to produce, often fragile, and dependent on any number of factors—including changes to various types of nerves. In the common fruit fly—a scientific doppelganger used to study human memory formation—these changes take place in multiple parts of the insect brain.
Scientists from the Florida campus of The Scripps Research Institute (TSRI) have been able to pinpoint a handful of neurons where certain types of memory formation occur, a mapping feat that one day could help scientists predict disease-damaged neurons in humans with the same specificity.
"What we found is that while a lot of the neurons will respond to sensory stimuli, only a certain subclass of neurons actually encodes the memory," said Seth Tomchik, a TSRI biologist who led the study, which was published March 27, 2014, online ahead of print by the journal Current Biology.
The researchers examined a type of neuron called dopaminergic neurons—which respond to dopamine, a well-known neurotransmitter—and are involved in shaping diverse behaviors, including learning, motivation, addiction and obesity.
In the study, the scientists followed the stimulation of a large number of these neurons when an odor was paired with an aversive event such as a mild electric shock. The scientists then used imaging technology to follow changes in the brains of live flies, mapping the activation patterns of signaling molecules within the neurons and observing learning-related plasticity—in which neurons change and develop memory traces.
The scientists found that the neurons that did encode memories responded to a cellular signaling messenger known as cAMP (cyclic adenosine monophosphate) that is vital for many biological processes. cAMP is involved in a number of psychological disorders such as bipolar disorder and schizophrenia, and its dysregulation may underlie some cognitive symptoms of Alzheimer’s disease and Neurofibramatosis I.
In fact, the study pointed to a specific location in the brain—a particular lobe with a region known as the mushroom body—where the neurons appear to be particularly sensitive to elevated amounts of cAMP.
According to Tomchik, that’s an important finding in terms of human memory because olfactory memory formation in the fruit fly is very similar to human memory formation.
"We have a good model in these two classes of neurons, one that encodes and one that doesn’t," he said. "Now we know exactly where the memory formation should be and where to look to see how disease may disrupt it."
Tamara Boto, the first author of the study and a member of Tomchik’s laboratory, added, “We know where, but we don’t yet know the mechanism of why only these subsets are affected. That’s our next job—to figure that out.”

neuromorphogenesis:

In mapping feat, scientists pinpoint neurons where select memories grow

Memories are difficult to produce, often fragile, and dependent on any number of factors—including changes to various types of nerves. In the common fruit fly—a scientific doppelganger used to study human memory formation—these changes take place in multiple parts of the insect brain.

Scientists from the Florida campus of The Scripps Research Institute (TSRI) have been able to pinpoint a handful of neurons where certain types of memory formation occur, a mapping feat that one day could help scientists predict disease-damaged neurons in humans with the same specificity.

"What we found is that while a lot of the neurons will respond to sensory stimuli, only a certain subclass of neurons actually encodes the memory," said Seth Tomchik, a TSRI biologist who led the study, which was published March 27, 2014, online ahead of print by the journal Current Biology.

The researchers examined a type of neuron called —which respond to dopamine, a well-known neurotransmitter—and are involved in shaping diverse behaviors, including learning, motivation, addiction and obesity.

In the study, the scientists followed the stimulation of a large number of these neurons when an odor was paired with an aversive event such as a mild electric shock. The scientists then used imaging technology to follow changes in the brains of live flies, mapping the activation patterns of signaling molecules within the neurons and observing learning-related plasticity—in which neurons change and develop memory traces.

The scientists found that the neurons that did encode memories responded to a cellular signaling messenger known as cAMP (cyclic adenosine monophosphate) that is vital for many biological processes. cAMP is involved in a number of psychological disorders such as bipolar disorder and schizophrenia, and its dysregulation may underlie some cognitive symptoms of Alzheimer’s disease and Neurofibramatosis I.

In fact, the study pointed to a specific location in the brain—a particular lobe with a region known as the mushroom body—where the neurons appear to be particularly sensitive to elevated amounts of cAMP.

According to Tomchik, that’s an important finding in terms of human memory because olfactory memory formation in the fruit fly is very similar to human memory formation.

"We have a good model in these two classes of neurons, one that encodes and one that doesn’t," he said. "Now we know exactly where the memory formation should be and where to look to see how disease may disrupt it."

Tamara Boto, the first author of the study and a member of Tomchik’s laboratory, added, “We know where, but we don’t yet know the mechanism of why only these subsets are affected. That’s our next job—to figure that out.”

(via behavioral-neuroscience)

neurosciencestuff:

Stem cell-based bioartificial tissues and organs
Surgeon Paolo Macchiarini has made his name by successfully transplanting bioengineered stem cell-based trachea, composed of both artificial and biological material. He now plans to use the technique to recreate more complex tissues, such as the oesophagus and diaphragm or organs such as the heart and lungs. He has also made an experimental attempt to regenerate brain in mice and rats. This is part of the news he will be presenting during his seminar at the scientific AAAS Annual Meeting in Boston.
In June 2011, media all over the world reported about a ground breaking transplant, where a patient received an artificial trachea covered in his own stem cells. The result was an artificial windpipe with biological functions. To date, five operations have been carried out using this technique.
"We learn something from each operation. This means we can develop and refine the technique. We are also evaluating how we can transfer our experiences to other fields, such as neurology. The aim is to make as much use of the body’s own healing potential as we can", says Paolo Macchiarini, Professor of Regenerative Surgery at Karolinska Institutet, and responsible for the surgery.
At the AAAS Annual Meeting, he will talk about how he believes the technology can be used in the future. This will include:
The plan to operate on a 2 year-old girl in the USA in March. The girl was born without a trachea and has lived her entire life in intensive care, where she breathes through a tube placed in the oesophagus and connected directly to the lungs. Without a new trachea, she will never be able to leave the hospital. This will be the first time the procedure is conducted on a small child. It is also the first time the procedure will be conducted on an individual without a trachea - as previously, diseased organs have been replaced.
There are also plans to transplant the oesophagus, an organ that is more complex than a trachea as it has muscles.
In experimental trials on rats, the research team has investigated the possibility to replace brain matter that has been damaged by serious trauma sustained from events such as traffic accidents, gunshot wounds or surgery. The aim is to replace the lost brain matter with a cultivated stem cell based substance and in turn, avoid neurological damage. The experimental attempt that has been conducted on rats and mice has shown positive results.
On two occasions, severely injured patients with acute refractory lung failure received stem cell based therapy showing immediate functional improvement. Although both patients died as a consequence of multi-organ failure, the result has provided the first evidence that stem cell therapy can be a promising alternative to restore function in certain damaged organs - without the need for them to be removed and replaced with healthy donor organs.

neurosciencestuff:

Stem cell-based bioartificial tissues and organs

Surgeon Paolo Macchiarini has made his name by successfully transplanting bioengineered stem cell-based trachea, composed of both artificial and biological material. He now plans to use the technique to recreate more complex tissues, such as the oesophagus and diaphragm or organs such as the heart and lungs. He has also made an experimental attempt to regenerate brain in mice and rats. This is part of the news he will be presenting during his seminar at the scientific AAAS Annual Meeting in Boston.

In June 2011, media all over the world reported about a ground breaking transplant, where a patient received an artificial trachea covered in his own stem cells. The result was an artificial windpipe with biological functions. To date, five operations have been carried out using this technique.

"We learn something from each operation. This means we can develop and refine the technique. We are also evaluating how we can transfer our experiences to other fields, such as neurology. The aim is to make as much use of the body’s own healing potential as we can", says Paolo Macchiarini, Professor of Regenerative Surgery at Karolinska Institutet, and responsible for the surgery.

At the AAAS Annual Meeting, he will talk about how he believes the technology can be used in the future. This will include:

  • The plan to operate on a 2 year-old girl in the USA in March. The girl was born without a trachea and has lived her entire life in intensive care, where she breathes through a tube placed in the oesophagus and connected directly to the lungs. Without a new trachea, she will never be able to leave the hospital. This will be the first time the procedure is conducted on a small child. It is also the first time the procedure will be conducted on an individual without a trachea - as previously, diseased organs have been replaced.
  • There are also plans to transplant the oesophagus, an organ that is more complex than a trachea as it has muscles.
  • In experimental trials on rats, the research team has investigated the possibility to replace brain matter that has been damaged by serious trauma sustained from events such as traffic accidents, gunshot wounds or surgery. The aim is to replace the lost brain matter with a cultivated stem cell based substance and in turn, avoid neurological damage. The experimental attempt that has been conducted on rats and mice has shown positive results.
  • On two occasions, severely injured patients with acute refractory lung failure received stem cell based therapy showing immediate functional improvement. Although both patients died as a consequence of multi-organ failure, the result has provided the first evidence that stem cell therapy can be a promising alternative to restore function in certain damaged organs - without the need for them to be removed and replaced with healthy donor organs.
brains-and-bodies:

From Neuroscience Research Techniques




Stroke and Alzheimer’s disease are characterized by both inflammation and hypoxia (loss of oxygen). A new study published in Neuron reveals how these two factors work together to contribute to memory loss and other cognitive problems. The key, found researchers at the University of British Columbia, are microglia, which are the immune system’s outpost in the brain. Scientists used microscopy images of the microglia in action, trying to repair damaged neurons. These images revealed that inflammation and hypoxia combine to keep microglia activated, which ends up decreasing neuron connection strength. This phenomenon, known as “long-term depression,” has identified in Alzheimer’s disease. The researchers hope to use these results to develop newer and better therapies to help prevent or repair brain damage.



Read more: http://bit.ly/Ndoy5VJournal article: Microglial CR3 Activation Triggers Long-Term Synaptic Depression in the Hippocampus via NADPH Oxidase. Neuron, 2014. doi: 10.1016/j.neuron.2014.01.043Image credit: Wellcome Images

brains-and-bodies:

From Neuroscience Research Techniques

Stroke and Alzheimer’s disease are characterized by both inflammation and hypoxia (loss of oxygen). A new study published in Neuron reveals how these two factors work together to contribute to memory loss and other cognitive problems. The key, found researchers at the University of British Columbia, are microglia, which are the immune system’s outpost in the brain. Scientists used microscopy images of the microglia in action, trying to repair damaged neurons. These images revealed that inflammation and hypoxia combine to keep microglia activated, which ends up decreasing neuron connection strength. This phenomenon, known as “long-term depression,” has identified in Alzheimer’s disease. The researchers hope to use these results to develop newer and better therapies to help prevent or repair brain damage.

Read more: http://bit.ly/Ndoy5V
Journal article: Microglial CR3 Activation Triggers Long-Term Synaptic Depression in the Hippocampus via NADPH Oxidase. Neuron, 2014. doi: 10.1016/j.neuron.2014.01.043
Image credit: Wellcome Images
wildcat2030:

Human nose can detect 1 trillion odours -What the the nose knows might as well be limitless, researchers suggest. - The human nose can distinguish at least 1 trillion different odours, a resolution orders of magnitude beyond the previous estimate of just 10,000 scents, researchers report today in Science Scientists who study smell have suspected a higher number for some time, but few studies have attempted to explore the limits of the human nose’s sensory capacity. “It has just been sitting there for somebody to do,” says study co-author Andreas Keller, an olfactory researcher at the Rockefeller University in New York.
..A human nose has around 400 types of scent receptors. When the smell of coffee wafts through a room, for example, specific receptors in the nose detect molecular components of the odour, eliciting a series of neural responses that draw one’s attention to the coffee pot.
(via Human nose can detect 1 trillion odours : Nature News & Comment)

wildcat2030:

Human nose can detect 1 trillion odours
-
What the the nose knows might as well be limitless, researchers suggest.
-
The human nose can distinguish at least 1 trillion different odours, a resolution orders of magnitude beyond the previous estimate of just 10,000 scents, researchers report today in Science Scientists who study smell have suspected a higher number for some time, but few studies have attempted to explore the limits of the human nose’s sensory capacity. “It has just been sitting there for somebody to do,” says study co-author Andreas Keller, an olfactory researcher at the Rockefeller University in New York.

..A human nose has around 400 types of scent receptors. When the smell of coffee wafts through a room, for example, specific receptors in the nose detect molecular components of the odour, eliciting a series of neural responses that draw one’s attention to the coffee pot.

(via Human nose can detect 1 trillion odours : Nature News & Comment)