Fragile X syndrome -- A stimulating environment restores neuronal function in mice

May 23, 2007

Fragile X syndrome is the most common form of inherited mental retardation, occurring in 1 in 3600 males and 1 in 4000 to 6000 females.

The researchers, led by Huibert Mansvelder, published their findings in the May 24, 2007 issue of the journal Neuron, published by Cell Press.

To understand the details of the neuronal pathology of Fragile X syndrome, the researchers studied mice in which the same gene that causes the disease in humans had been knocked out. The scientists performed a detailed analysis of the electrophysiological properties of neurons in the prefrontal cortex, a region responsible for higher cognitive functions, including learning and memory, that are affected in humans with the disorder.

The scientists’ analysis revealed that the neurons in the mice showed reduction of a particular form of a process called "long-term potentiation" that is central to the formation of new circuit pathways in learning and memory. The researchers’ experiments showed that this reduction was due to abnormalities in the pore-like channels that regulate the flow of calcium into neurons.

Importantly, they found that increased stimulation of neurons in the mice, which enhanced calcium signaling, could restore normal long-term potentiation and neuronal plasticity.

There have been reports that Fragile X patients can still learn and memorize information but need more repetition and stimulation. Also, studies by other researchers had shown that exposing Fragile X knockout mice to a stimulating environment ameliorated behavioral and neuronal abnormalities.

So, Mansvelder and colleagues tested whether exposure of the knockout mice to an enriched environment caused higher stimulation that would restore normal neuronal plasticity. They gave such mice a variety of cage toys, and also gave them time in play cages that contained running wheels, tunnels, different bedding material, and interesting objects.

The researchers found that such an enriched environment did, indeed, restore normal neuronal plasticity. The researchers concluded that "increased sensory, cognitive, and motor stimulation by environmental enrichment facilitates the development of synaptic plasticity in cortical areas involved in higher cognitive function. The results of this study demonstrate that in prefrontal cortex of Fragile X knockout mice, excitatory synapses can show lasting increases in synaptic strength, but this requires increased neuronal activity to occur."

Source: Cell Press

Explore further: New compounds protect nervous system from the structural damage of MS

add to favorites email to friend print save as pdf

Related Stories

Canada looks east-west to ship oil after Keystone veto

4 hours ago

After US President Barack Obama vetoed a bill to expedite construction of the Keystone XL pipeline Tuesday, petroleum producers are expected to turn to Canadian routes to ship oil internationally, but hurdles ...

Internet access limited in developing world

4 hours ago

Most people in the developing world do not use the Internet, with access limited by high costs, poor availability and a lack of relevant content, a Facebook report said Tuesday.

Manhattan Project physicist Ralph Nobles dies at 94

5 hours ago

(AP)—Ralph Nobles, a nuclear physicist who worked on the Manhattan Project and later led efforts to save thousands of acres of San Francisco Bay wetlands from development, died following complications of pneumonia, according ...

In Japan, robot dogs are for life - and death

5 hours ago

Incense smoke wafts through the cold air of the centuries-old Buddhist temple as a priest chants a sutra, praying for the peaceful transition of the souls of the departed.

US sees little severe weather so far in 2015

5 hours ago

(AP)—While a big chunk of the nation deals with snow and ice, the U.S. is poised to end January and February with the fewest bouts of severe weather in decades.

Recommended for you

Mystery of the reverse-wired eyeball solved

13 hours ago

From a practical standpoint, the wiring of the human eye - a product of our evolutionary baggage - doesn't make a lot of sense. In vertebrates, photoreceptors are located behind the neurons in the back of the eye - resulting ...

Neurons controlling appetite made from skin cells

13 hours ago

Researchers have for the first time successfully converted adult human skin cells into neurons of the type that regulate appetite, providing a patient-specific model for studying the neurophysiology of weight ...

Quality control for adult stem cell treatment

16 hours ago

A team of European researchers has devised a strategy to ensure that adult epidermal stem cells are safe before they are used as treatments for patients. The approach involves a clonal strategy where stem cells are collected ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.