Author: Parizad Bilimoria

On the clock: Circadian genes may regulate brain plasticity

brain circadian rhythmsFirst in a two-part series on circadian biology and disease. Read part 2.

It’s long been known that a master clock in the hypothalamus, deep in the center of our brain, governs our bodily functions on a 24-hour cycle. It keeps time through the oscillatory activity of timekeeper molecules, much of which is controlled by a gene fittingly named Clock.

It’s also been known that the timekeeper molecules and their regulators live outside this master clock, but what exactly they do there remains mysterious. A new study reveals one surprising function: they appear to regulate the timing of brain plasticity—the ability of the brain to learn from and change in response to experiences.

“We found that a cell-intrinsic Clock may control the normal trajectory of brain development,” says Takao Hensch, PhD, a professor in the Departments of Molecular and Cellular Biology and Neurology at Harvard University and a member of the F.M. Kirby Neurobiology Center at Boston Children’s Hospital.

Read Full Story | Leave a Comment

Sensory processing problems in autism: Mice reveal brain mechanisms, treatment potential

sensory processing autism
(Image courtesy Nadine Gogolla)

Families of children with autism spectrum disorder have long noted sensory processing difficulties such as heightened sensitivity to noise, touch or smell—or even specific foods or clothing textures—earning sensory processing a place in the official DSM-5 description of the disorder.

“A high proportion of kids with autism spectrum disorder will have difficulty tolerating certain kinds of sensory inputs,” says Carolyn Bridgemohan, MD, co-director of the Autism Spectrum Center at Boston Children’s Hospital. Others, she adds, are less sensitive to certain stimuli, showing a higher tolerance for pain or excessively hot or cold temperatures.

A study published last week in Neuron uses mouse models to shed new light on the brain mechanisms that underlie sensory processing abnormalities in autism.

Read Full Story | 1 Comment | Leave a Comment

Parvalbumin neurons—new insight into the workings of a superhero brain cell

Superhero Cell 6-Parizad BilimoriaSay you’re a scientist in a movie, and you want to find out what gives a superhero his powers. You’d investigate any special suits he wears, whether he drinks any potions and what they are, right? Real-life scientists are following the same strategy to understand a powerful group of specialized brain cells.

Parvalbumin cells (PV-cells) are a population of inhibitory neurons found throughout the cerebral cortex. While small in number and size, they have the impressive capability to synchronize the electrical activities of other brain cells and orchestrate the timing of critical periods, interludes when the brain is more “plastic” and amenable to rewiring. Abnormalities in these pivotal cells are believed to make plasticity go awry, playing an important role in autism, schizophrenia and other neurodevelopmental disorders.

“The PV-cell is vulnerable in many mental illnesses,” says Takao K. Hensch, PhD, of the F.M. Kirby Neurobiology Center at Boston Children’s Hospital and professor of molecular and cellular biology and neurology at Harvard University. “So if we can find a way to maintain its health and well-being, then we might have a way to treat neurodevelopmental disorders, even later in life.”

Read Full Story | Leave a Comment

More accolades for omega 3’s

Omega-3’s are emerging superheroes in the nutrition world. Over two decades ago, scientists noticed that Greenland Eskimos had very low rates of coronary heart disease compared to Western populations. Their secret, it turned out, was eating fish—particularly, fatty fishes like salmon that contain a lot of omega-3 fatty acids.

An avalanche of studies have since demonstrated the cardiovascular health benefits of omega-3 fatty acids, also found in flax seeds and walnuts, as well as suggesting benefits in combating depression, rheumatoid arthritis and some types of cancer, and in boosting cognitive function.

And now comes more evidence that they can prevent blindness.

Read Full Story | Leave a Comment

How good are social networking sites for patients?

A teenager with type I diabetes has general admission tickets to a U2 concert. She’ll have to stand in a crowd all day to get a decent spot, and wonders how to make sure her blood sugar doesn’t hit a dangerous low.

A grandpa with type II diabetes is tired of people thinking he can’t ever have any sweets. And a new mom with diabetes is too overwhelmed with her baby and work to manage her illness.

All three, from different nations and continents, recently shared their stories on a social networking site for diabetics – part of an increasing trend for patients to turn to online social networks for healthcare. I came across their stories, along with some identifying information, without even having to register as a member of the site I was on.

But is this a bad thing?

Read Full Story | 3 Comments | Leave a Comment

A urine test for brain tumors?

A urine sample can tell you many things. It can reveal pregnancy, signal an infection or unmask drug use. Could it also tell you about brain tumors? Maybe.

Current image-based screening for brain tumors and other neurologic diseases is time-consuming, costly and poses some risk—especially for young children who must be sedated to hold still in the scanner. The ordeal is multiplied for children who have had brain surgery and need frequent checks for disease resurgence — especially if they don’t live close to pediatric neuroimaging facilities.

Read Full Story | Leave a Comment

The science of spinal cord repair: where we are

For more than a century, neuroscientists have been trying to figure out how to repair broken nerves in the spinal cord–and the rest of the central nervous system–after injury. They’ve produced a steady stream of promising discoveries–treatments that promote nerve growth in the laboratory dish and animals, even some reports of paralyzed rodents regaining motor function. So why are people with spinal cord injury (SCI) still without therapies that repair their nerve damage?

Read Full Story | 2 Comments | Leave a Comment

Kid scientists tell why research is “cool and fun”

A group of 8 to 10 year old British schoolchildren just reported original findings in the journal Biology Letters, a peer-reviewed journal from Britain’s prestigious Royal Society. The research was born from their curiosity about nature: how do bees decide what flowers to get their nectar from? Might the color of the flowers matter? And how the flowers are arranged?

Designing a careful series of tests—in which some flowers had sugar water (like nectar) and others had salt water—the children from Blackawton Primary School, Devon, demonstrate that bees can use a combination of color and spatial cues to learn. As neatly detailed in the handwritten graphs and drawings with colored pencils, many bees figured out over time which flowers had the sugar water: the blue flowers surrounded by a ring of yellow flowers, or the yellow flowers surrounded by a ring of blue flowers—but never flowers on the outside.

Read Full Story | Leave a Comment

Neurogenetic disorders: Dreaming the impossible dream

People with autism and most other disorders of brain development have never had medications to treat their core behavioral and cognitive symptoms. The best they can get are drugs targeting secondary problems, like irritability or aggression. But now, a new wave of clinical trials, such as the one we posted about yesterday for Rett syndrome, aims to change this.

In the last decade, scientists have discovered many of the molecular pathways in genetic disorders that can impair cognition and place a child on the autism spectrum—such as tuberous sclerosis complex, Rett syndrome, Fragile X syndrome and Angelman syndrome. These discoveries are suggesting targets for drug treatment, and is changing how these conditions—and perhaps neurodevelopmental disorders generally—are viewed.

Read Full Story | Leave a Comment

Alzheimer’s drugs for “lazy eye”?

When my parents told me I should walk around with my right eye patched like a pirate—on regular days, not just Halloween—I wondered if they were joking. They weren’t: those really were the doctor’s orders.

As a child, I had amblyopia, or “lazy eye”: my left eye had much poorer vision than my right eye. The eye itself was fine, but my brain wasn’t processing information coming from it. The plan was, by patching the “good” eye, to force my brain to use inputs from the amblyopic eye.

Read Full Story | Leave a Comment