neurosciencestuff:

Researchers Reveal Pathway that Contributes to Alzheimer’s Disease
Researchers at Jacksonville’s campus of Mayo Clinic have discovered a defect in a key cell-signaling pathway they say contributes to both overproduction of toxic protein in the brains of Alzheimer’s disease patients as well as loss of communication between neurons — both significant contributors to this type of dementia.
Their study, in the online issue of Neuron, offers the potential that targeting this specific defect with drugs “may rejuvenate or rescue this pathway,” says the study’s lead investigator, Guojun Bu, Ph.D., a neuroscientist at Mayo Clinic, Jacksonville, Fla.
“This defect is likely not the sole contributor to development of Alzheimer’s disease, but our findings suggest it is very important, and could be therapeutically targeted to possibly prevent Alzheimer’s or treat early disease,” he says.
The pathway, Wnt signaling, is known to play a critical role in cell survival, embryonic development and synaptic activity — the electrical and chemical signals necessary for learning and memory. Any imbalance in this pathway (too much or too little activity) leads to disease — the overgrowth of cells in cancer is one example of overactivation of this pathway.
While much research on Wnt has focused on diseases involved in overactive Wnt signaling, Dr. Bu’s team is one of the first to demonstrate the link between suppressed Wnt signaling and Alzheimer’s disease.
“Our finding makes sense, because researchers have long known that patients with cancer are at reduced risk of developing Alzheimer’s disease, and vice versa,” Dr. Bu says. “What wasn’t known is that Wnt signaling was involved in that dichotomy.”
Using a new mouse model, the investigators discovered the key defect that leads to suppressed Wnt signaling in Alzheimer’s. They found that the low-density lipoprotein receptor-related protein 6 (LRP6) is deficient, and that LRP6 regulates both production of amyloid beta, the protein that builds up in the brains of AD patients, and communication between neurons. That means lower than normal levels of LRP6 leads to a toxic buildup of amyloid and impairs the ability of neurons to talk to each other.
Mice without LRP6 had impaired Wnt signaling, cognitive impairment, neuroinflammation and excess amyloid.
The researchers validated their findings by examining postmortem brain tissue from Alzheimer’s patients — they found that LRP6 levels were deficient and Wnt signaling was severely compromised in the human brain they examined.
The good news is that specific inhibitors of this pathway are already being tested for cancer treatment. “Of course, we don’t want to inhibit Wnt in people with Alzheimer’s or at risk for the disease, but it may be possible to use the science invested in inhibiting Wnt to figure out how to boost activity in the pathway,” Dr. Bu says.
“Identifying small molecule compounds to restore LRP6 and the Wnt pathway, without inducing side effects, may help prevent or treat Alzheimer’s disease,” he says. “This is a really exciting new strategy — a new and fresh approach.”

neurosciencestuff:

Researchers Reveal Pathway that Contributes to Alzheimer’s Disease

Researchers at Jacksonville’s campus of Mayo Clinic have discovered a defect in a key cell-signaling pathway they say contributes to both overproduction of toxic protein in the brains of Alzheimer’s disease patients as well as loss of communication between neurons — both significant contributors to this type of dementia.

Their study, in the online issue of Neuron, offers the potential that targeting this specific defect with drugs “may rejuvenate or rescue this pathway,” says the study’s lead investigator, Guojun Bu, Ph.D., a neuroscientist at Mayo Clinic, Jacksonville, Fla.

“This defect is likely not the sole contributor to development of Alzheimer’s disease, but our findings suggest it is very important, and could be therapeutically targeted to possibly prevent Alzheimer’s or treat early disease,” he says.

The pathway, Wnt signaling, is known to play a critical role in cell survival, embryonic development and synaptic activity — the electrical and chemical signals necessary for learning and memory. Any imbalance in this pathway (too much or too little activity) leads to disease — the overgrowth of cells in cancer is one example of overactivation of this pathway.

While much research on Wnt has focused on diseases involved in overactive Wnt signaling, Dr. Bu’s team is one of the first to demonstrate the link between suppressed Wnt signaling and Alzheimer’s disease.

“Our finding makes sense, because researchers have long known that patients with cancer are at reduced risk of developing Alzheimer’s disease, and vice versa,” Dr. Bu says. “What wasn’t known is that Wnt signaling was involved in that dichotomy.”

Using a new mouse model, the investigators discovered the key defect that leads to suppressed Wnt signaling in Alzheimer’s. They found that the low-density lipoprotein receptor-related protein 6 (LRP6) is deficient, and that LRP6 regulates both production of amyloid beta, the protein that builds up in the brains of AD patients, and communication between neurons. That means lower than normal levels of LRP6 leads to a toxic buildup of amyloid and impairs the ability of neurons to talk to each other.

Mice without LRP6 had impaired Wnt signaling, cognitive impairment, neuroinflammation and excess amyloid.

The researchers validated their findings by examining postmortem brain tissue from Alzheimer’s patients — they found that LRP6 levels were deficient and Wnt signaling was severely compromised in the human brain they examined.

The good news is that specific inhibitors of this pathway are already being tested for cancer treatment. “Of course, we don’t want to inhibit Wnt in people with Alzheimer’s or at risk for the disease, but it may be possible to use the science invested in inhibiting Wnt to figure out how to boost activity in the pathway,” Dr. Bu says.

“Identifying small molecule compounds to restore LRP6 and the Wnt pathway, without inducing side effects, may help prevent or treat Alzheimer’s disease,” he says. “This is a really exciting new strategy — a new and fresh approach.”

fuckyeahfluiddynamics:

Terminator 2's T-1000, a liquid metal robot capable of changing its shape at will, just became a little less far-fetched. Researchers at NC State have reported a new method for controlling the form of a liquid gallium alloy. Surface tension governs the shape a liquid assumes when it is not confined by a container, and, although adding surfactants can slightly lower the surface tension, it does not substantially alter the liquid’s shape. Adding soap to water lets one make bubbles, but surface tension keeps the bubbles spherical no matter how much soap you add. Instead, these researchers control the surface tension of the liquid metal using a mild voltage. Applying a voltage creates (or removes) an oxide layer on the liquid metal’s surface, thereby altering the surface tension. By controlling the formation of the oxide layer, the researchers can change the surface tension from approximately 7x that of water to nearly zero. The video above demonstrates some of the liquid shape control this lets them achieve.  (VIdeo credit: M. Dickey et al.; research: M. Khan et al.; via PopSci)

neurosciencestuff:

Brain Structure of Kidney Donors May Make Them More Altruistic
That’s the finding of a study published in today’s Proceedings of the National Academy of Sciences (PNAS) by Georgetown researchers.
Georgetown College psychology professor Abigail Marsh worked with John VanMeter, director of Center for Functional and Molecular Imaging at Georgetown University Medical Center, to scan the brains of 19 altruistic kidney donors.
More Sensitive to Distress
“The results of brain scans and behavioral testing suggests that these donors have some structural and functional brain differences that may make them more sensitive, on average, to other people’s distress,” Marsh explains.
The Georgetown researchers used functional MRI to record the neural activity of the kidney donors and 20 control subjects who had never donated an organ as they viewed faces with fearful, angry or neutral expressions.
Underlying Neural Basis
In the right amygdala, an emotion-sensitive brain region, altruists displayed greater neural activity while viewing fearful expressions than did control subjects.
When asked to identify the emotional expressions presented in the face images, altruists recognized fearful facial expressions relatively more accurately than the control subjects.
“The brain scans revealed that the right amygdala volume of altruists is larger than that of non-altruists,” Marsh says. “The findings suggest that individual differences in altruism may have an underlying neural basis.”
Opposite From Psychopaths?
These findings dovetail with previous research by the professor showing  structural and functional brain differences that appear to make people with psychopathic traits less sensitive to others’ fear and distress.
These differences include amygdalas that are smaller and less responsive to fearful expressions. People who are unusually altruistic may therefore be the opposite in some ways from people who are psychopathic.
To find kidney donors, the researchers reached out to the Washington Regional Transplant Community (WRTC), a federally designated organ procurement organizations.
A Donor’s Story
Harold Mintz, former northern Virginian who volunteered with WRTC and agreed to participate in the Georgetown study, donated a kidney to an anonymous stranger he later learned was an Ethiopian refugee who had settled in Washington, D.C.
Mintz, who now lives in California and speaks to high school students about his 2000 donation, says a series of events over time led him to supply the kidney, including his father dying of cancer diagnosed too late at the age of 56.
One Valentine’s Day in 1988, Mintz and his wife were shopping separately for presents and Mintz noticed parents in a mall with a sign saying “Please Save Our Daughter’s Life.” He walked past them, then turned around and asked what they needed. It turned out the daughter had leukemia and needed a bone marrow transplant.
The couple decided to forget about the holiday and donated blood to see if either of them were a match. But no match was found and Mintz later noticed the daughter’s obituary in the newspaper.
Stories Taken to Heart
Mintz also was surprised to hear that although the couple’s daughter had just died, they thanked everyone who tried to help and expressed hope that they might help someone else.
“All these stories just kind of stuck inside my head and every time I’d see a story about a medical story of distress, it would just kind of get put away in a file inside my heart,” Mintz says.
Marsh notes that kidney disease is now the eighth-leading cause of death in the U.S., and that living kidney donations are the best hope for restoring people to health who have kidney disease.
“Dr. Marsh’s work is a great example of how fMRI can be used to provide insight into how differences in the brain’s response can lead individuals to perform such magnanimous acts,” VanMeter says.

neurosciencestuff:

Brain Structure of Kidney Donors May Make Them More Altruistic

That’s the finding of a study published in today’s Proceedings of the National Academy of Sciences (PNAS) by Georgetown researchers.

Georgetown College psychology professor Abigail Marsh worked with John VanMeter, director of Center for Functional and Molecular Imaging at Georgetown University Medical Center, to scan the brains of 19 altruistic kidney donors.

More Sensitive to Distress

“The results of brain scans and behavioral testing suggests that these donors have some structural and functional brain differences that may make them more sensitive, on average, to other people’s distress,” Marsh explains.

The Georgetown researchers used functional MRI to record the neural activity of the kidney donors and 20 control subjects who had never donated an organ as they viewed faces with fearful, angry or neutral expressions.

Underlying Neural Basis

In the right amygdala, an emotion-sensitive brain region, altruists displayed greater neural activity while viewing fearful expressions than did control subjects.

When asked to identify the emotional expressions presented in the face images, altruists recognized fearful facial expressions relatively more accurately than the control subjects.

“The brain scans revealed that the right amygdala volume of altruists is larger than that of non-altruists,” Marsh says. “The findings suggest that individual differences in altruism may have an underlying neural basis.”

Opposite From Psychopaths?

These findings dovetail with previous research by the professor showing  structural and functional brain differences that appear to make people with psychopathic traits less sensitive to others’ fear and distress.

These differences include amygdalas that are smaller and less responsive to fearful expressions. People who are unusually altruistic may therefore be the opposite in some ways from people who are psychopathic.

To find kidney donors, the researchers reached out to the Washington Regional Transplant Community (WRTC), a federally designated organ procurement organizations.

A Donor’s Story

Harold Mintz, former northern Virginian who volunteered with WRTC and agreed to participate in the Georgetown study, donated a kidney to an anonymous stranger he later learned was an Ethiopian refugee who had settled in Washington, D.C.

Mintz, who now lives in California and speaks to high school students about his 2000 donation, says a series of events over time led him to supply the kidney, including his father dying of cancer diagnosed too late at the age of 56.

One Valentine’s Day in 1988, Mintz and his wife were shopping separately for presents and Mintz noticed parents in a mall with a sign saying “Please Save Our Daughter’s Life.” He walked past them, then turned around and asked what they needed. It turned out the daughter had leukemia and needed a bone marrow transplant.

The couple decided to forget about the holiday and donated blood to see if either of them were a match. But no match was found and Mintz later noticed the daughter’s obituary in the newspaper.

Stories Taken to Heart

Mintz also was surprised to hear that although the couple’s daughter had just died, they thanked everyone who tried to help and expressed hope that they might help someone else.

“All these stories just kind of stuck inside my head and every time I’d see a story about a medical story of distress, it would just kind of get put away in a file inside my heart,” Mintz says.

Marsh notes that kidney disease is now the eighth-leading cause of death in the U.S., and that living kidney donations are the best hope for restoring people to health who have kidney disease.

“Dr. Marsh’s work is a great example of how fMRI can be used to provide insight into how differences in the brain’s response can lead individuals to perform such magnanimous acts,” VanMeter says.

nubbsgalore:

lightning illuminates an ash cloud that extends ten kilometres high in this june 5, 2011 eruption of puyehue volcano, near osorno in southern chile. known as a dirty thunderstorm, this phenomenon is yet to be explained by science, as the source of the lightning (or the specific mechanism by which particles of differing charges are separated in the ash cloud) continues to be debated.   

photos by (click pic) claudio santanaivan alvarado, francisco negroni and carlos gutierrez.  (see also: the eruption of japan’s sakurajima volcano and the eruptions in eyjafjallajokull, iceland