Performing cellular surgery with a laser-powered nanoblade

Date:May 10, 2016

Source:Cell Press

Summary: To study certain aspects of cells, researchers need the ability to take the innards out, manipulate them, and put them back. Options for this kind of work are limited, but researchers describe a ‘nanoblade’ that can slice through a cell’s membrane to insert mitochondria. The researchers have previously used this technology to transfer other materials between cells and hope to commercialize the nanoblade for wider use in bioengineering.

To study certain aspects of cells, researchers need the ability to take the innards out, manipulate them, and put them back. Options for this kind of work are limited, but researchers reporting May 10 in Cell Metabolism describe a “nanoblade” that can slice through a cell’s membrane to insert mitochondria. The researchers have previously used this technology to transfer other materials between cells and hope to commercialize the nanoblade for wider use in bioengineering.

“As a new tool for cell engineering, to truly engineer cells for health purposes and research, I think this is very unique,” says Mike Teitell, a pathologist and bioengineer at the University of California, Los Angeles (UCLA). “We haven’t run into anything so far, up to a few microns in size, that we can’t deliver.”

Teitell and Pei-Yu “Eric” Chiou, also a bioengineer at UCLA, first conceived the idea of a nanoblade several years ago to transfer a nucleus from one cell to another. However, they soon delved into the intersection of stem cell biology and energy metabolism, where the technology could be used to manipulate a cell’s mitochondria. Studying the effects of mutations in the mitochondrial genome, which can cause debilitating or fatal diseases in humans, is tricky for a number of reasons.

“There’s a bottleneck in the field for modifying a cell’s mitochondrial DNA,” says Teitell. “So we are working on a two-step process: edit the mitochondrial genome outside of a cell, and then take those manipulated mitochondria and put them back into the cell. We’re still working on the first step, but we’ve solved that second one quite well.”

The nanoblade apparatus consists of a microscope, laser, and titanium-coated micropipette to act as the “blade,” operated using a joystick controller. When a laser pulse strikes the titanium, the metal heats up, vaporizing the surrounding water layers in the culture media and forming a bubble next to a cell. Within a microsecond, the bubble expands, generating a local force that punctures the cell membrane and creates a passageway several microns long that the “cargo”–in this case, mitochondria–can be pushed through. The cell then rapidly repairs the membrane defect.

Teitell, Chiou, and their team used the nanoblade to insert tagged mitochondria from human breast cancer cells and embryonic kidney cells into cells without mitochondrial DNA. When they sequenced the nuclear and mitochondrial DNA afterwards, the researchers saw that the mitochondria had been successfully transferred and replicated by 2% of the cells, with a range of functionality. Other methods of mitochondrial transfer are hard to control, and when they have been reported to work, the success rates have been only 0.0001%-0.5% according to the researchers.

“The success of the mitochondrial transfer was very encouraging,” says Chiou. “The most exciting application for the nanoblade, to me, is in the study of mitochondria and infectious diseases. This technology brings new capabilities to help advance these fields.”

The team’s aspirations also go well beyond mitochondria, and they’ve already scaled up the nanoblade apparatus into an automated high-throughput version. “We want to make a platform that’s easy to use for everyone and allow researchers to devise anything they can think of a few microns or smaller that would be helpful for their research–whether that’s inserting antibodies, pathogens, synthetic materials, or something else that we haven’t imagined,” says Teitell. “It would be very cool to allow people to do something that they can’t do right now.”

Story Source:

The above post is reprinted from materials provided by Cell Press. Note: Materials may be edited for content and length.

Journal Reference:

  1. Ting-Hsiang Wu, Enrico Sagullo, Dana Case, Xin Zheng, Yanjing Li, Jason S. Hong, Tara TeSlaa, Alexander N. Patananan, J. Michael McCaffery, Kayvan Niazi, Daniel Braas, Carla M. Koehler, Thomas G. Graeber, Pei-Yu Chiou, Michael A. Teitell. Mitochondrial Transfer by Photothermal Nanoblade Restores Metabolite Profile in Mammalian Cells. Cell Metabolism, 2016; 23 (5): 921 DOI: 10.1016/j.cmet.2016.04.007

Clean energy generated using bacteria-powered solar panel

Date:April 11, 2016

Source:Binghamton University

Summary: For the first time ever, researchers have connected nine biological-solar (bio-solar) cells into a bio-solar panel. Then they continuously produced electricity from the panel and generated the most wattage of any existing small-scale bio-solar cells – 5.59 microwatts.

These are nine biological-solar (bio-solar) cells connected into a bio-solar panel. The panel has generated the most wattage of any existing small-scale bio-solar cells – 5.59 microwatts
Credit: Seokheun “Sean” Choi

Researchers have taken the next step in the evolution of bacteria-powered energy.

For the first time ever, researchers connected nine biological-solar (bio-solar) cells into a bio-solar panel. Then they continuously produced electricity from the panel and generated the most wattage of any existing small-scale bio-solar cells — 5.59 microwatts.

“Once a functional bio-solar panel becomes available, it could become a permanent power source for supplying long-term power for small, wireless telemetry systems as well as wireless sensors used at remote sites where frequent battery replacement is impractical,” said Seokheun “Sean” Choi, an assistant professor of electrical and computer engineering in Binghamton University’s Thomas J. Watson School of Engineering and Applied Science, and co-author of the paper.

Choi is the corresponding author of the paper “Biopower generation in a microfluidic bio-solar panel,” which reported the findings.

“This research could also enable crucial understanding of the photosynthetic extracellular electron transfer processes in a smaller group of microorganisms with excellent control over the microenvironment, thereby enabling a versatile platform for fundamental bio-solar cell studies,” said Choi.

Xuejian Wei, a graduate student in the department, and Hankeun Lee ’15, who will graduate from Binghamton in May, were also authors of the study.

The current research is the latest step in using cyanobacteria (which can be found in almost every terrestrial and aquatic habitat on the planet) as a source of clean and sustainable energy. Last year, the group took steps toward building a better bio-solar cell by changing the materials used in anodes and cathodes (positive and negative terminals) of the cell and also created a miniature microfluidic-based single-chambered device to house the bacteria instead of the conventional, dual-chambered bio-solar cells.

However, this time the group connected nine identical bio-solar cells in a 3×3 pattern to make a scalable and stackable bio-solar panel. The panel continuously generated electricity from photosynthesis and respiratory activities of the bacteria in 12-hour day-night cycles over 60 total hours.

“Bio-solar cell performance has improved significantly through miniaturizing innovative device architectures and connecting multiple miniature cells in a panel,” the report said. “This could result in barrier-transcending advancements in bio-solar cells that could facilitate higher power/voltage generation with self-sustainability, releasing bio-solar cell technology from its restriction to research settings, and translating it to practical applications in real-world.”

Even with the breakthrough, a typical “traditional” solar panel on the roof of a residential house, made up of 60 cells in a 6×10 configuration, generates roughly 200 watts of electrical power at a given moment. The cells from this study, in a similar configuration, would generate about 0.00003726 watts.

So, it isn’t efficient just yet, but the findings open the door to future research of the bacteria itself.

“It is time for breakthroughs that can maximize power-generating capabilities/energy efficiency/sustainability,” Choi said. “The metabolic pathways of cyanobacteria or algae are only partially understood, and their significantly low power density and low energy efficiency make them unsuitable for practical applications. There is a need for additional basic research to clarify bacterial metabolism and energy production potential for bio-solar applications.”

The Binghamton University Nanofabrication Lab provided the fabrication facilities for the work, while the University Research Foundation (Interdisciplinary Collaborations Grants (ICG) Program/Transdisciplinary Areas of Excellence) provided the funding.

The findings are currently available online and will be published in hard copy in the June edition of the journal Sensors and Actuators B: Chemical.

Study Suggests Brain Damage in 40 Percent of Ex-NFL Players

MONDAY, April 11, 2016 (HealthDay News) —

Two out of five retired National Football League players may suffer from traumatic brain injuries, a small study suggests.

Brain scans of 40 former NFL players, age 36 on average, found that nearly 43 percent had significantly more damage to the brain’s white matter than healthy adults the same age, researchers said.

Also, testing showed about half had significant problems following through on goals, and more than two out of five had learning, memory or attention problems.

“This is another piece of the puzzle that playing football places people at risk for traumatic brain injury that may cause problems later in life,” said lead researcher Dr. Francis Conidi, from the Florida Center for Headache and Sports Neurology, in Port St. Lucie.

Traumatic brain injury may be a precursor to chronic traumatic encephalopathy (CTE), a progressive degenerative disease of the brain, Conidi said. “It’s important to prevent traumatic brain injury, because there is nothing you can do when they reach CTE,” he said.

Conidi added that one-third of people with traumatic brain injuries go on to develop Alzheimer’s, CTE or other neurodegenerative diseases.

The NFL, which for years disputed the notion that head injuries led to brain damage, said in a statement that it values studies of this kind.

“It is clear there are long-term health risks associated with sustaining head injuries,” said an NFL spokesman. “Studies of this nature are important to further advancing the science and better understanding these risks.”

One way to reduce the danger of traumatic brain injury in football is to limit hitting in practice, Conidi said, “because the damage is most likely cumulative.”

“You can’t take the hitting completely away without compromising the game,” Conidi said. However, “there is an accepted risk by the athlete,” he added. “As long as we can present the information that you may have problems later in life, they can make an informed decision.”

Another expert welcomed the report.

“Overall, this is a significant study highlighting the potential damage that can occur over time, especially in professional sports,” said Dr. Mohan Kottapally, an assistant professor of clinical neurology and neurocritical care at the University of Miami Miller School of Medicine.

However, Kottapally said the study findings don’t necessarily establish a direct cause-and-effect relationship between the MRI findings and observable thinking problems. More information is needed for that, he said.

“The difficulty we face in treating patients with this disease is in determining the connection between imaging findings of dysfunction with clinical findings of dysfunction,” he said.

The former athletes in the study ranged in age from 27 to 56. They played in the NFL for an average of seven years and reported an average of eight concussions, Conidi said.

In addition, 12 men reported several sub-concussive hits — hard blows that weren’t diagnosed as a concussion, he said.

When the researchers used special MRIs and examined the brain’s white matter, which connects brain regions, they found 17 players had evidence of traumatic brain injury, Conidi said.

Also, 30 percent had disruption of the nerve cells that allow brain cells to send messages to each other, he said.

It appeared those who played the longest were most likely to have signs of traumatic brain injury.

The number of concussions suffered, however, was not related to signs of traumatic brain injury, Conidi said.

The explanation must lie somewhere else, Conidi said. One possible cause is that hits during play — not necessarily head hits — cause strain deep within the brain’s white matter, which result in lasting damage, he said.

This may be why offensive and defensive linemen were most likely to show signs of traumatic brain injury, he said. “It’s not concussion, it’s the banging that appears to be causing the problems here,” he added.

“We have possibly found a link to CTE or an alternative explanation for some of the neurological problems people are finding in retired football players,” he said.

The study findings were scheduled for presentation Tuesday at the American Academy of Neurology’s annual meeting in Vancouver, Canada. The research should be considered preliminary until published in a peer-reviewed medical journal.

SOURCES: Francis Conidi, M.D., D.O., Florida Center for Headache and Sports Neurology, Port St. Lucie; Mohan Kottapally, M.D., assistant professor, clinical neurology and neurocritical care, University of Miami Miller School of Medicine; National Football League statement, April 11, 2016; abstract, April 19, 2016, presentation, American Academy of Neurology, annual meeting, Vancouver, Canada

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Anxiety may lead to bad decision-making

Written by
Published: Wednesday 16 March 2016
Scared about speaking in public? Nervous about a job interview? These anxious feelings are familiar to most of us. But while some people are able to sweep them under the rug, for others, anxiety can become such a problem that it controls their day-to-day lives. And according to a new study, it may even lead to bad decision-making.

Lead author Bita Moghaddam, of the Department of Neuroscience at the University of Pittsburgh in Pennsylvania, and colleagues publish their findings in The Journal of Neuroscience.

[A woman struggling to make a decision]
Anxiety could affect the ability to make good choices, according to researchers.

According to the National Alliance on Mental Illness (NAMI), anxietydisorders – including post-traumatic stress disorder (PTSD), panic disorder and social anxiety disorder – affect around 18.1% of the population in the US.

Moghaddam and her team note that previous research investigating the effects of anxiety on the brain has primarily focused on the emotional response, such as how the brain cells of animal models respond to threatening situations.

But anxiety does not only have emotional implications for humans; it can also negatively impact everyday life, from preventing a person going to work, to interfering with personal relationships.

As such, the team set out to investigate how anxiety impacts one key aspect of day-to-day life: decision-making – defined as the cognitive process of making a choice from a number of possible alternatives.

Anxiety interferes with choice-making cells in the prefrontal cortex

To reach their findings, the researchers analyzed the brain cells, or neurons, in the prefrontal cortex (PFC) of two groups of rats as they completed a decision-making task, in which they had to make a decision about which choice was most logical for receiving a reward.

The PFC is an area of the brain that plays a key role in flexible decision-making.

One group of rats received a low-dose anxiety-inducing drug prior to the task, while the other group received a placebo injection.

While the anxious rats did complete the decision-making task – as would humans with anxiety – the team found that the rodents made significantly more mistakes than the non-anxious rats when the decision-making process involved ignoring distracting information to reach a logical choice.

The researchers found that these mistakes were down to anxiety’s effects on a group of neurons in the PFC that code specifically for making choices; anxiety hampered their coding ability.

Overall, the team believes the findings indicate that anxiety may interfere with our ability to make good decisions by interfering with a specific set of neurons in the PFC.

Commenting on the findings, Moghaddam says:

“We have had a simplistic approach to studying and treating anxiety. We have equated it with fear and have mostly assumed that it over-engages entire brain circuits. But this study shows that anxiety disengages brain cells in a highly specialized manner.”

She adds that gaining a better understanding of how anxiety affects decision-making could eventually lead to improved treatments for anxiety disorders and other psychiatric illnesses.

In January, Medical News Today reported on a study suggesting anxiety may increase the risk of dementia by affecting the PFC and amygdala regions of the brain.

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Barrow neurosurgeon helps pave way for deep brain stimulation to treat Alzheimer’s

Adapted Media Release Published: Monday 29 February 2016 email

Neurosurgeons at Barrow Neurological Institute in Phoenix are involved with testing the viability of deep brain stimulation (DBS) to treat Alzheimer’s disease, a disorder that currently has few treatment options. Results from the Phase 2 study, reported in the Journal of Neurosurgery on Dec. 18, 2015, demonstrated the safety of DBS in Alzheimer’s patients.

A neurosurgical procedure in which an implanted neurostimulator delivers electrical signals to specific areas of the brain to help regulate abnormal signals, DBS is currently only approved in the U.S. for the treatment of Parkinson’s disease andessential tremor. However, its use is being researched for a number of conditions, including epilepsy, depression andbipolar disorder. Francisco Ponce, MD, Director of the Barrow Center for Neuromodulation, believes there are potential applications for Alzheimer’s disease – the most common form of dementia – as well. Whereas in Parkinson’s disease and essential tremor, the target for the electrodes are nodes within the motor circuits, the Alzheimer’s study targeted the fornix, which is part of the memory pathway.

“There are more than five million Americans living with Alzheimer’s, and yet there are few promising pharmacologic treatment options for this progressive disease,” says Dr. Ponce. “Previous pilot studies researching the use of DBS in Alzheimer’s have indicated the potential to slow cognitive decline in some patients, and have even shown metabolic changes in the brain that may slow the progression of the disease.” Barrow Neurological Institute is part of Dignity Health St. Joseph’s Hospital in Phoenix.

The ADvance Trial, using a device from Functional Neuromodulation, Inc., is aimed at evaluating the safety, efficacy and tolerability of DBS in this patient population. Initial research took place between 2012 and 2014 at six hospitals throughout the U.S., including Banner Alzheimer’s Institute in Phoenix and Banner Sun Health Research Institute in Sun City, as well as one institution in Canada. During the trial, 42 patients with mild Alzheimer’s disease underwent the surgical procedure and were closely monitored for adverse effects.

Overall, there were no programming-related adverse effects, unanticipated adverse device effects, reported neurological deficits or instances of mortality in the study population. Adverse effects such as headache and infection occurred in 11.9% (5 of 42) of the patients in this study, consistent with rates reported in other DBS trials.

“The first phase of this study was designed to evaluate the 90-day postoperative safety of this particular surgical method. While the study was relatively small, we believe the data suggest that DBS surgery targeting the fornix can be performed safely in this patient population. The hope is that our positive surgical experience will help pave the way for future research into DBS and Alzheimer’s,” says Dr. Ponce.

Dr. Ponce adds that the next step is evaluating the efficacy and longer-term safety of the treatment, which will not be known until the last patient completes the two-year evaluation later this year.

Bilateral deep brain stimulation of the fornix for Alzheimer’s disease: surgical safety in the ADvance trial. Francisco A. Ponce, MD, Wael F. Asaad, MD, PhD, Kelly D. Foote, MD, William S. Anderson, MD, PhD, G. Rees Cosgrove, MD, Gordon H. Baltuch, MD, PhD, Kara Beasley, DO, MBe, Donald E. Reymers, Esther S. Oh, MD, Steven D. Targum, MD, Gwenn S. Smith, PhD, Constantine G. Lyketsos, MD, MHS, and Andres M. Lozano, MD, PhD for The ADvance Research Group. Journal of Neurosurgery. DOI.10.3171/2015.6.JNS15716. Published online December 18, 2015.

Source: St. Joseph’s Hospital and Medical Center.

Additional source: EurekAlert!, the online, global news service operated by AAAS, the science society

Thyroid and breast cancer survivors at risk of the other malignancy

Women who survive either breast or thyroid cancer are at greater risk of developing the other type in the future as a secondary malignancy, says research published in Cancer Epidemiology, Biomarkers & Prevention.
[mammogram]
Regular surveillance after cancer treatment can help to catch secondary malignancies in good time.

Breast cancer is the most common type of cancer in women. In 2012, there were 224,147 new cases diagnosed, and 41,150 women died of the disease.

The thyroid gland is located at the base of the throat. The hormones that it produces help to regulate heart rate, body temperature and weight. The shape is like a butterfly, with a right and a left lobe, connected by a piece of tissue.

There are four types of thyroid cancer: papillary, follicular, medullary, and anaplastic. Papillary is the most common type of thyroid cancer. Anaplastic is the most difficult to treat, but the other three can normally be cured, according to the National Cancer Institute (NCI).

The incidence of thyroid cancer has almost tripled in the US in the last 30 years, but progress in detecting and treating both breast and thyroid cancer means that many more women are now surviving their first illness.

It now seems that women who survive one disease have a high risk of developing the other.

Breast cancer survivors have a 1.55 times higher risk of thyroid cancer

Dr. Raymon H. Grogan, assistant professor of surgery and director of the Endocrine Surgery Research Program at the University of Chicago Medicine and Biological Sciences in Illinois, and colleagues carried out a meta-analysis using PubMed and Scopus databases.

They looked at cases of breast and thyroid cancer over several decades and identified who had survived one cancer, and who went on to develop the other type later in life. They also calculated the risk of developing a secondary cancer.

The team found that a breast cancer survivor was 1.55 times more likely to develop thyroid cancer than a woman with no history of breast cancer. A woman who had had thyroid cancer was 1.18 times more likely to develop breast cancer than one with no history of thyroid cancer.

Fast facts about thyroid cancer

  • In 2015, 62,450 Americans were diagnosed with thyroid cancer, 47,230 of them women
  • 1,950 people died of thyroid cancer, of whom 1,080 were women
  • 2 in 3 thyroid cancer diagnoses are for people under 50 years of age.

Learn more about thyroid cancer

The team offers a number of possible explanations.

The first is surveillance bias. A cancer patient is more likely to be followed up and to adhere to a screening regime for some years after the treatment, increasing the chance of having a secondary cancer detected, even at an early stage.

There could be common hormonal risk factors for both diseases. Previous studies suggest that exposure to estrogens and to thyroid-stimulating hormones could, theoretically, contribute to the development of a secondary breast or thyroid cancer.

Treatment for the first cancer could affect the risk of developing the second. Radiation is a common tool in the fight against breast cancer, and studies show this could increase the risk of certain lung, esophageal, blood cancers and sarcomas, among others.

Radiation exposure is a risk factor for thyroid cancer, although protecting the thyroid during treatment should minimize the danger.

The authors say there is evidence that the use of radioactive iodine (RAI) in the treatment of thyroid cancer may have a very small impact on the development of other cancers at a later date, including breast cancer. How great this risk is remains unclear.

from the Medical News Today

Cocaine users present alterations in the function and structures of the brain

A new study published in Addiction Biology, the highest-impact journal in the field of addictions, has shown the presence of alterations in brain functioning and structure in cocaine users. The study was led by the Research Group on Human Neuropsychopharmacology, Institute of Biomedical Research (IIB-Sant Pau), in collaboration with the Addictive Behaviours Unit, Department of Psychiatry, Hospital de la Santa Creu i Sant Pau, the Cognition and Brain Plasticity Group, Bellvitge Biomedical Research Institute (IDIBELL) and the Department of Pharmacology and Therapeutics, Universitat Autònoma de Barcelona. These researchers used three different magnetic resonance imaging techniques to study the brain activation patterns and the integrity of grey and white matter in cocaine users.

In the study cocaine users performed a gambling task while measurements were being taken of their brain activity. The researchers discovered that cocaine users present a state of hyperactivation in the ventral striatum, a deep region of the brain that forms part of the so-called “reward circuit”. This circuit is extremely ancient in evolutionary terms and is made up of different interconnected regions that favour basic behaviours like eating and sex.

In the course of the study cocaine users displayed greater activation than healthy subjects, both when the outcomes obtained in the gambling task were favourable (winning money) and when they were adverse (losing money). This generalised hypersensitivity in the ventral striatum was accompanied by an anomalous activation profile in the prefrontal cortex. This brain region is much more evolved and is tasked with regulating behaviour, being able to inhibit the automatic, impulsive behaviours favoured by the ventral striatum.

The results showed that while in healthy individuals an unfavourable outcome in the gambling task leads to a robust activation of this region, in cocaine users it remains inactive and does not respond to the adverse consequences of their behaviour.

The study also revealed structural differences between the brains of users and non-users. Analysis of the volume of grey matter in cocaine users revealed hypertrophy of the caudate nucleus and the orbitofrontal cortex: two areas of the brain that belong to the reward circuit and which have been linked to compulsive behaviours.

Furthermore, analysis of white matter integrity in the same group found increased connectivity in the areas involved in reward processing, but decreased connectivity outside these areas. The bundles of white matter are tasked with transmitting information between distant areas of the brain. In cocaine users these connecting pathways seem to be reinforced among the structures concerned with gratification but degraded among areas that control important cognitive processes like behaviour regulation and attention.

To sum up, the study’s results suggest that in cocaine users there is an alteration of the functional and structural balance between the ventral striatum and the prefrontal cortex. This could lead to difficulties in setting priorities, taking decisions and inhibiting inappropriate behaviours. These deficits can explain several symptoms of addiction, such as craving for drugs and self-control issues. The researchers postulate that the fact that not only is there an alteration to the brain’s functioning but also to its structure could explain the great difficulties addicts have in giving up drugs and the large numbers of relapses that these patients experience. This gives an insight into the negative impacts on the health and social lives of drug users.

Repeated consumption of substances that produce pleasure and euphoria can lead to addiction. This chronically recurring disorder is characterised by the loss of control in drug use. Scientists are trying to determine why addictions develop and why it is so difficult for users to stop taking drugs.

from the Medical News Today

 

December 17 – Conditions of Blessing

egi1Jesus, we love Thee. We see that all things are planned by Thee. We rejoice in that vision.

Rejoice in the fact that you are Mine. The privileges of the members of My Kingdom are many. When I said of My Father, “He maketh His Sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust,” you will notice it was the temporal and material blessings I spoke.

I did not mean that the believer and unbeliever could be treated alike. That is not possible; I can send rain and sunshine and money and worldly blessings equally to both, but of the blessing of the Kingdom that would be impossible.

There are conditions that control the bestowal of these. My followers do not always understand this, it is necessary they should do so if they are remembering My injunction which followed — “Be ye therefore perfect even as your Father in Heaven is perfect.”

To attempt to bestow on all alike your Love and Understanding and interchange of thought would be impossible. But temporal blessings you too bestow, as does My Father. All must be done in Love and in the spirit of true forgiveness.

“Ye have not chosen me, but I have chosen you, and ordained you, that
ye should go and bring forth fruit, and that your fruit should remain.” John 15:16

Psalms 6:2: Have mercy upon me, O LORD; for I am weak: O LORD, heal me; for my bones are vexed.

A certain king, being once very sad, his brother asked what ailed him. “Oh, brother,” he said, “I have been a great sinner, and am afraid to die and appear before God in judgment.” His brother only laughed at him for his melancholy thoughts. The king said nothing, but in the dead of night sent the executioner to sound his trumpet before his brother’s door, that being the signal for a man to be led out to execution. Pale and trembling, his brother came in haste to the king and asked to know his crime. “Oh, brother,” said the king, “you have never offended against me; but if the sight of the executioner be so dreadful, shall not I, who have grievously offended God, fear to be brought before the judgment seat of Jesus Christ?”
(from The Biblical Illustrator Copyright © 2002, 2003, 2006 Ages Software, Inc. and Biblesoft, Inc.)

 

First-of-kind dopamine measurements in human brain reveal insights into how we learn

Virginia Tech Carilion Research Institute scientists measure dopamine signals in Parkinson’s patients.

Virginia Tech Carilion Research Institute scientists have reported measurements of dopamine release with unprecedented temporal precision in the brains of people with Parkinson’s disease. The measurements, collected during brain surgery as the conscious patients played an investment game, demonstrate how rapid dopamine release encodes information crucial for human choice.

The findings may have widespread implications not just for Parkinson’s disease, but for other neurological and psychiatric disorders as well, including depression and addiction.

The researchers detected changes in the levels of dopamine a thousand times faster than had previously been recorded in humans. These rapid measurements, combined with enhanced chemical specificity, led the scientists to discover that dopamine – a crucial neurotransmitter involved in learning and decision-making – has a far more complex role than formerly thought.

The study was published today in the Proceedings of the National Academy of Sciences.

“More than 20 years of research in nonhuman model organisms has painted a very specific picture of the suspected role of dopamine in guiding human behavior,” said Read Montague, director of the Human Neuroimaging Laboratory at the Virginia Tech Carilion Research Institute and senior author of the paper. “And now, with these first-of-their-kind measurements, made directly in humans, we’ve discovered that this picture was woefully incomplete.”

Montague and his team worked neurosurgeons at Wake Forest University Health Sciences – Stephen Tatter, Adrian Laxton, and the late Thomas Ellis – to measure dopamine signals in patients with Parkinson’s disease undergoing surgery to implant deep-brain stimulation electrodes. Deep-brain stimulation has been shown to alleviate Parkinson’s disease symptoms.

Seventeen patients volunteered to allow Montague’s team to record their dopamine signals during implantation surgery.

“We’re studying a system that’s falling apart in their brains,” said Ken Kishida, first author of the paper and a research scientist at the Virginia Tech Carilion Research Institute. “Parkinson’s disease is characterized by the death of dopamine-releasing neurons, and we’re trying to understand the underlying mechanisms of the disease process.”

Kishida and Montague both noted the generosity of the patients who volunteered for the study.

“This type of access to measure dopamine signals is invaluable,” Kishida said. “And we’ve made these measurements in 17 people – that’s 17 more than ever before.”