Understanding Angelman Syndrome

Neuron firing imbalance may be the cause of seizures in patients with neurogenetic disorder

(RxWiki News) For families and caretakers of those with Angelman syndrome, research into causes of seizures is vital, as the consequences of seizures can range from disruption of daily life to death.

Researchers conducted a study into the link between neuron activity imbalance and seizures in those with Angelman syndrome.

The study found a significant imbalance between neuron excitation and inhibition.

The research was led by Benjamin D. Philpot, PhD, professor of cell and molecular physiology at the University of North Carolina. The study explored the circuit pathways of the brain in mice that displayed similar behavior and seizures to those experienced by humans with Angelman syndrome.

"Ask your doctor for advice on treating and managing seizures"

Philpot and team used precise recording electrodes and microscopic tips attached to individual neurons to record brain activity.

A normally functioning brain self-regulates neurons that create and stop electrical activity.

Philpot’s team found that inhibitory neurons that were sent to stop excitatory neurons were defective. These defective neurons decreased the mouse’s ability to recover from high levels of brain activity.

The inability of neurons to inhibit electrical activity caused an overload of firing neurons and created a hyperexcitable state. This is similar to what happens in the brain when a person goes into an epileptic seizure. The brain cell activity imbalance may also be the underlying cause of cognitive impairments

About 90 percent of Angelman syndrome patients experience seizures.

The syndrome affects 1 in 15,000 births and is characterized by symptoms similar to autism and cerebral palsy. These symptoms include a happy demeanor, seizures, cognitive delay, intellectual disability, lack of speech, sleep disturbance, hand flapping and motor and balance disorders.

Angelman syndrome is caused by the loss of a maternally inherited gene component during fetal development.

Past studies suggested that loss of the same gene component in animals is associated with a decrease of excitatory neuron activity, thereby increasing the activity of other neurons. This study clarifies the issue.

This key understanding of how changes in the connections between neurons create seizures may help patients with Angelman syndrome receive better treatment in the future.

The study was published in the June edition of the journal Neuron and was funded by the Angelman Syndrome Foundation.

Additional funding was provided by the National Institute of Neurological Disorders and Stroke, the Simons Foundation, the National Eye Institute, and the National Institute of Mental Health.

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Review Date: 
June 27, 2012