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. Earlier studies in people suggested that a particular breed of nerve fibers detects a caress and carries that signal to the brain

scientists hadn’t been able to directly link this type of neuron to good feelings, either in people or in animals.

Directly linking these neurons with pleasure clarifies the importance of touch

The new study relied on mice genetically engineered so that a select population of nerve cells would glow when they sensed a caress

These neurons,

possessed the attributes of massage sensors, but they stubbornly refused to respond to touch in experiments in lab dishes

by touching the genetically engineered animals’ skin, the researchers were able to study these cells in live mice.

A harsher poke, with a more focused point of pressure, didn’t elicit a reaction from the cells

These neurons, which all carry a protein called MRGPRB4, seem tuned to detect a steady stroke

the researchers tested whether this stroke felt good to mice

the scientists used a different kind of genetically engineered mouse, one with caress-sensitive neurons that a drug could activate

When the researchers dispensed the drug in a particular room, the mice soon learned to prefer that room over others

associating it with the presumably enjoyable sensation of being stroked

not yet clear whether the nerve fibers in the mice have exact analogs in humans,

new view of caress detection

offers a deeper understanding of touch.

Now some patients are getting such repairs for valves, irregular heartbeats, holes in the heart and other defects—without major surgery

Doctors even are testing ways to treat high blood pressure with some of these new approaches

Instead of opening the chest, we're able to put catheters in through the leg, sometimes through the arm

Many patients after having this kind of procedure in a day or two can go home

It may lead to cheaper treatment, although the initial cost of the novel devices often offsets the savings from shorter hospital stays

Not everyone can have catheter treatment, and some promising devices have hit snags in testing

Others on the market now are so new that it will take several years to see if their results last as long as the benefits from surgery do.

these procedures have allowed many people too old or frail for an operation to get help for problems that otherwise would likely kill them

You can do these on 90-year-old patients

also offer an option for people who cannot tolerate long-term use of blood thinners or other drugs to manage their conditions

Heart valves

Millions of people have leaky heart valves. Each year, more than 100,000 people in the United States alone have surgery for them

Without a valve replacement operation, half of these patients die within two years, yet many are too weak to have one.

just over a year ago,

Edwards Lifesciences Corp. won approval to sell an artificial aortic valve flexible and small enough to fit into a catheter and be wedged inside the bad one

At first it was just for inoperable patients. Last fall, use was expanded to include people able to have surgery but at high risk of complications.

Catheter-based treatments for other valves also are in testing. One for the mitral valve

mixed review by federal Food and Drug Administration advisers this week; whether it will win FDA approval is unclear. It is already sold in Europe

Heart rhythm problems

Catheters can contain tools to vaporize or "ablate" bits of heart tissue that cause abnormal signals that control the heartbeat

Now catheter ablation is being used for the most common rhythm problem—atrial fibrillation, which plagues about 3 million Americans and 15 million people worldwide.

Ablation addresses the underlying rhythm problem. To address the stroke risk from pooled blood, several novel devices aim to plug or seal off the pouch

The upper chambers of the heart quiver or beat too fast or too slow. That lets blood pool in a small pouch off one of these chambers

Clots can form in the pouch and travel to the brain, causing a stroke

a tiny lasso to cinch the pouch shut. It uses two catheters that act like chopsticks. One goes through a blood vessel and into the pouch to help guide placement of the device, which is contained in a second catheter poked under the ribs to the outside of the heart. A loop is released to circle the top of the pouch where it meets the heart, sealing off the pouch.

A different kind of device

sold in Europe and parts of Asia, but is pending before the FDA in the U.S

like a tiny umbrella pushed through a vein and then opened inside the heart to plug the troublesome pouch.

Early results from a pivotal study released by the company suggested it would miss a key goal, making its future in the U.S. uncertain.

Heart defects

St. Jude Medical Inc.'s Amplatzer is a fabric-mesh patch threaded through catheters to plug the hole

In two new studies, the device did not meet the main goal of lowering the risk of repeat strokes in people who had already suffered one, but some doctors were encouraged by other results

Сlogged arteries

The original catheter-based treatment—balloon angioplasty—is still used hundreds of thousands of times each year in the U.S. alone

A Japanese company, Terumo Corp., is one of the leaders of a new way to do it that is easier on patients—through a catheter in the arm rather than the groin

Newer stents that prop arteries open and then dissolve over time, aimed at reducing the risk of blood clots, also are in late-stage testing

High blood pressure

About

1 billion people worldwide have high blood pressure, a major risk factor for heart attacks

Researchers are testing a possible long-term fix for dangerously high pressure that can't be controlled with multiple medications.

uses a catheter and radio waves to zap nerves, located near the kidneys, which fuel high blood pressure

At least one device is approved in Europe and several companies are testing devices in the United States

target a particular type of brain inflammation

brain inflammation, also called neuroinflammation, is increasingly believed to play a major role in the progressive damage characteristic of these chronic diseases and brain injuries.

offers an entirely different therapeutic approach to Alzheimer's than current ones being tested to prevent the development of beta amyloid plaques in the brain

The plaques are an indicator of the disease but not a proven cause

given to a mouse genetically engineered to develop Alzheimer's, it prevents the development of the full-blown disease

identifies the optimal therapeutic time window for administering the drug, which is taken orally and easily crosses the blood-brain barrier.

In previous animal studies, the same drug reduced the neurological damage caused by closed-head traumatic brain injury and inhibited the development of a multiple sclerosis-like disease. In these diseases as well as in Alzheimer's, the studies show the therapy time window is critical

work by preventing the damaging overproduction of brain proteins called proinflammatory cytokines

Scientists now believe overproduction of these proteins contributes to the development of many degenerative neurological diseases

When too many of the cytokines are produced, the synapses of the brain begin to misfire

mouse model of Alzheimer's received MW151 three times a week starting at six months of age, right at the time the proinflammatory cytokines began to rise. This would be the comparable stage when a human patient would begin to experience mild cognitive impairment

drug protected against the damage associated with learning and memory impairment

before Alzheimer's memory changes are at a late stage may be a promising future approach to therapy

In M.S., overproduction of the proinflammatory cytokines damage the central nervous system and the brain

proteins directly or indirectly destroy the insulation or coverings of the nerve cells that transmit signals down the spinal cord

insulation is stripped, messages aren't properly conducted down the spinal cord

When mice that were induced to develop an M.S.-like disease received MW151 orally, they did not develop disease as severe.

After a traumatic brain injury, the glia cells in the brain become hyperactive and release a continuous cascade of proinflammatory cytokines

As a result of this hyperactivity, researchers believe the brain is more susceptible to serious damage following a second neurological injury.

when MW151 is given during an early therapeutic window three to six hours after the injury, it blocks glial activation and prevents the flood of proinflammatory cytokines after a traumatic brain injury

early on after traumatic brain injury or a even a stroke, you could possibly prevent the long-term complications of that injury including the risk of seizures, cognitive impairment and, perhaps, mental health issues

Stroke also causes inflammation in the brain that may also be linked to long-term complications including epilepsy and cognitive deficits

and how it can learn very similar tasks without interference between them.

The key

is that neurons are constantly changing their connections with other neurons

not all of the changes are functionally relevant - they simply allow the brain to explore many possible ways to execute a certain skill, such as a new tennis stroke

As the brain learns a new motor skill, neurons form circuits that can produce the desired output

according to this theory

As the brain explores different solutions, neurons can become specialized for specific tasks

brain is always trying to find the configurations that balance everything so you can do two tasks, or three tasks, or however many you're learning

Perfection is usually not achieved on the first try, so feedback from each effort helps the brain to find better solutions

complications arise when the brain is trying to learn many different skills at once

Because the same distributed network controls related motor tasks, new modifications to existing patterns can interfere with previously learned skills.

particularly tricky when you're learning very similar things

such as two different tennis strokes

computer chip,

instructions for each task would be stored in a different location on the chip.

the brain is not organized like a computer chip. Instead, it is massively parallel and highly connected - each neuron connects to, on average, about 10,000 other neurons

That connectivity offers an advantage, however, because it allows the brain to test out so many possible solutions to achieve combinations of tasks

neurons

have a very low signal to noise ratio, meaning that they receive about as much useless information as useful input from their neighbors

The constant changes in these connections,

researchers call hyperplasticity

balanced by another inherent trait of

Most models of neural activity don't include noise, but the MIT team says noise is a critical element of the brain's learning ability

This model helps to explain how the brain can learn new things without unlearning previously acquired skills

the paper shows is that, counterintuitively, if you have neural networks and they have a high level of random noise, that actually helps instead of hindering the stability problem

Without noise, the brain's hyperplasticity would overwrite existing memories too easily

low plasticity would not allow any new skills to be learned, because the tiny changes in connectivity would be drowned out by all of the inherent noise

The constantly changing connections explain why skills can be forgotten unless they are practiced often, especially if they overlap with other routinely performed tasks

skills such as riding a bicycle, which is not very similar to other common skills, are retained more easily

Once you've learned something, if it doesn't overlap or intersect with other skills, you will forget it but so slowly that it's essentially permanent

researchers are now investigating whether this type of model could also explain how the brain forms memories of events, as well as motor skills

I began to sleep better at night

spasms are decreased

better bladder control

the exoskeleton is good for the skin, muscles, bones, circulation, and it decreases the risk of blood clots and wounds

In the absence of a cure

using technological devices to help them to gain mobility and to be able to better care for themselves

this electrically powered robot where they actually can go distances without exhausting themselves

one downside, and that's the cost, which is up to $140,000 for a single unit

as more and more patients use it and the technology is simplified, the cost is expected to come down.

made the findings in mice, whose brains are remarkably similar to the human brain

Scientists have known that cerebrospinal fluid or CSF plays an important role cleansing brain tissue, carrying away waste products and carrying nutrients to brain tissue through a process known as diffusion

The newly discovered system circulates CSF to every corner of the brain much more efficiently, through what scientists call bulk flow or convection

It's as if the brain has two garbage haulers – a slow one that we've known about, and a fast one that we've just met

How has this system eluded the notice of scientists up to now

the system operates only when it's intact and operating in the living brain, making it very difficult to study

study the living, whole brain, the team used a technology known as two-photon microscopy, which allows scientists to look at the flow of blood, CSF and other substances in the brain of a living animal

If the glymphatic system fails to cleanse the brain as it is meant to, either as a consequence of normal aging, or in response to brain injury, waste may begin to accumulate in the brain. This may be what is happening with amyloid deposits in Alzheimer's disease

Perhaps increasing the activity of the glymphatic system might help prevent amyloid deposition from building up or could offer a new way to clean out buildups of the material in established Alzheimer's disease

took an in-depth look at amyloid beta

found that more than half the amyloid removed from the brain of a mouse under normal conditions is removed via the glymphatic system

As temperatures inside the body fall, several failsafe systems spring into action

Blood vessels near the skin squeeze tight to hold warmth in, the body starts to shiver and brown fat, a tissue that’s especially plentiful in newborns, starts to produce heat

colleagues bypassed the rats’ defenses against the cold with a compound that’s similar to adenosine, a molecule in the body that signals sleepiness

After about an hour in a room chilled to 15° Celsius, the rats grew lethargic

brain waves slowed, their blood pressure dropped and their heart grew sluggish, occasionally skipping beats

The rats’ core temperature dropped from about 38°  to about 30° C, or 80° Fahrenheit

measured even lower temperatures in further experiments — rats’ core body temperature reached 15° C or about 57° F.

The rats weren’t in a coma, nor were they asleep or truly hibernating

Hibernating animals’ metabolisms plummet and their temperatures sink much lower

an Arctic ground squirrel, for instance, cools to about —3° C when it hibernates

It’s a new state

don’t really know what it is

In the experiment, loud noises and tail pinches failed to arouse the rats.

They didn’t eat or drink. Occasionally, one would slither into a corner, but for the most part, the animals stayed still for up to 6 hours

In unpublished experiments, Tupone has kept the animals in the unresponsive state for 24 hours, he says.

Warming the room coaxed the rats out of their torpor

The recovery process takes about 12 hours, during which the animals ate and drank voraciously

After recovering, the animals were alert, moved around their cages normally and slept when tired

When people have heart attacks or strokes, clinicians can use ice packs or frigid water to chill people and prevent further tissue damage

those methods of cooling take time and can have dangerous side effects

Stimulation Therapy for Apnea Reduction (STAR) trial

conducted at 22 medical centers in the United States and Europe

OSA, which affects more than 8 million men and 4 million women in the U.S. and is twice as common in men

is characterized by repeated episodes of upper airway collapse during sleep, due to narrowing or blockage

Patients with OSA stop breathing, known as apnea, frequently during sleep, often for a minute or longer

Repeated episodes of apnea can lead to daytime fatigue, and increase a person's risk for heart attack, stroke, high blood pressure and even death.

Treatments for OSA include weight loss, upper airway surgeries, oral appliances, and continuous positive airway pressure (CPAP), which is considered the primary treatment for OSA

CPAP is a successful treatment when used on a regular basis, as many as half of the patients who have been prescribed CPAP are unable to use it regularly

largely due to discomfort with the mask and/or the lack of desire to be tethered to a machine

Inspire UAS therapy

differs from other traditional sleep apnea devices and surgical procedures

targets the muscle tone of the throat rather than just the anatomy

Two thirds of patients using the Inspire UAS therapy device had successful control of their OSA

even more reported improvement in snoring, daytime sleepiness and quality of life measures

Eighty-six percent of patients were still using the device every night at the one year mark, which compares very favorably to CPAP

From 724 candidates initially screened, the STAR trial implanted and prospectively evaluated 126 moderate-to-severe OSA patients who had difficulty using or adhering to CPAP therapy:

83 percent of the participants were men, the mean age was 54.5 years, and the mean body-mass index was 28.4.

All patients underwent surgery to implant the device.

The device stimulates the nerve of the tongue during sleep, thereby enlarging and stabilizing the airway and improving control of breathing.

Surgical implantation of the upper-airway stimulation system was performed by otolaryngologists at 22 academic and private centers

The device was implanted in three areas

stimulation electrode was placed on the hypoglossal nerve, which provides innervation to the muscles of the tongue

a sensing lead was placed between rib muscles to detect breathing effort

a neurostimulator was implanted in the upper right chest, just below the clavicle bone

Patients used a "controller" to turn on the device at night, so it is only used when the patient sleeps

device is designed to sense breathing patterns and deliver mild stimulation to a patient's airway muscles to keep the airway open during sleep.

various sleep-disorder measuring systems, patients were found to experience 68 to 70 percent fewer sleep-apnea episodes per hou