Breaking News
September 19, 2018 - Novel deep learning drug discovery platform gets £1 million innovation boost
September 19, 2018 - Sensor array may detect de novo Parkinson’s disease in breath
September 19, 2018 - A roadmap for the future of electronic health records
September 19, 2018 - Surprising research showing peptide adaptability may pave way to develop immunotherapies
September 19, 2018 - Amyloid β protein makes comeback as therapeutic target for Alzheimer’s disease
September 19, 2018 - Alcon expands its global support of eye care professionals through Alcon Experience Academy
September 19, 2018 - Study gives new insights into how cells leverage GPCRs to control inflammation
September 19, 2018 - Automatic relevance detection in ophthalmic surgery videos
September 19, 2018 - UNIST to accelerate discovery, development of new medicines for incurable diseases
September 19, 2018 - Novel clinical trial to examine cannabis as potential treatment for essential tremor
September 19, 2018 - Salsa dancers have lower injury rates than Spanish, aerobic or Zumba dancers
September 19, 2018 - Bristol-Myers Squibb’s Novel, Oral, Selective TYK2 Inhibitor Delivered Significant Skin Clearance in Patients with Moderate to Severe Plaque Psoriasis in Phase 2 Trial
September 19, 2018 - Can work stress contribute to Parkinson’s disease risk?
September 19, 2018 - Global Climate Action Summit: A focus on kids and climate
September 19, 2018 - Vitamin D may reduce breast cancer mortality in women with lower BMI
September 19, 2018 - Targeted Lung Denervation procedure significantly reduces COPD problems
September 19, 2018 - FDA-approved ‘safe’ daily BPA exposure may contribute to insulin resistance
September 19, 2018 - Research finds physical connection between the brain’s fluid reservoirs and meningeal lymphatics
September 19, 2018 - UCalgary study could help physicians make better treatment decisions for stroke
September 19, 2018 - Biomedical review finds failure rates in some surgical mesh treatments to be unacceptably high
September 19, 2018 - Researchers develop more accurate measure of body fat
September 19, 2018 - Doctors and students rally to support gun violence research, education
September 19, 2018 - LEO Pharma and MorphoSys announce expansion of strategic alliance to develop peptide-derived drugs
September 19, 2018 - Seniors in pain hop aboard the canna-bus
September 19, 2018 - New compound could prevent malaria parasites from maturing inside mosquito
September 19, 2018 - Scientists find alterations in blood flow in response to body position change
September 19, 2018 - UNC Health Care extends free access to virtual care service in the aftermath of Hurricane Florence
September 19, 2018 - Opioid Refills Rare After Rhinoplasty
September 19, 2018 - Corn, obesity, and navigating healthy eating choices as a parent
September 19, 2018 - Journal editor aims to prompt thoughtful review of ethics in precision health
September 19, 2018 - Researchers identify key step in how plant cells respond to pathogens
September 18, 2018 - Researchers analyze how exposure to silver nanoparticles affects zebrafish
September 18, 2018 - Study shows air pollution may be bad for the fetus
September 18, 2018 - Coffee May Have Another Perk for Kidney Patients
September 18, 2018 - Tongue-in-cheek Nobels honor nutritional analysis of cannibalism, roller-coaster kidney stones treatment
September 18, 2018 - Progress, priorities, challenges are focus of State of Stanford Medicine | News Center
September 18, 2018 - Established Alzheimer’s Risk Gene Has a New Role
September 18, 2018 - Hospitalization after antibiotic initiation found to be higher for people with Alzheimer’s disease
September 18, 2018 - Many children with special healthcare needs do not have access to ‘PCMH-concordant’ care
September 18, 2018 - Investigational nasal influenza vaccine tested in children and teens
September 18, 2018 - Lymphatic vessels surrounding the brain play crucial role in multiple sclerosis, research suggests
September 18, 2018 - New fiber laser-based ultrasound sensor may have potential applications in medical diagnostics
September 18, 2018 - Protect your heart and health during ‘dog days’ of summer
September 18, 2018 - Faculty receive awards for promise in biomedical research, clinical care | News Center
September 18, 2018 - Digital games for CVD-related self-management improve exercise capacity and energy expenditure
September 18, 2018 - Aluminum inclusions help enhance adsorption of chemo drugs onto active carbon delivery capsule
September 18, 2018 - Adding PET scans to CT imaging can change treatment for women with cervical cancer
September 18, 2018 - UCSF awarded $20 million grant to study impacts of new, emerging tobacco products
September 18, 2018 - Human brains may be wired to prefer lying on the couch, suggests research
September 18, 2018 - Zika virus vaccine shows promise for treatment of fatal glioblastoma
September 18, 2018 - Theravance Biopharma and Mylan to Report New Data from Phase 3 Studies of Yupelri (revefenacin) in Oral Presentation at European Respiratory Society International Congress 2018
September 18, 2018 - INSiGHT identifies unique retinal regulatory genes
September 18, 2018 - Diversity, science leadership grants awarded to student-faculty pairs | News Center
September 18, 2018 - Many parents blame electronics for sleep problems among teens
September 18, 2018 - Researchers study neuronal activity in brain that prevents individuals from doing physical activity
September 18, 2018 - Purifying Proteins from Mammalian Cell Culture
September 18, 2018 - Researchers map 3D structure of toxic proteins used by Pseudomonas aeruginosa to trigger infection
September 18, 2018 - Outcome of ACL reconstruction related to the way you move post-surgery
September 18, 2018 - Study aims to investigate risk factors for PPCs in surgical patients with gastric cancer
September 18, 2018 - Ardelyx Submits New Drug Application for Tenapanor for IBS-C
September 18, 2018 - Sociodemographic disparities in eyeglass use among elderly
September 18, 2018 - New Drug Shows Promise for Progressive Form of MS
September 18, 2018 - Babies exposed to higher levels of organochlorine compounds in womb may have worse lung function
September 18, 2018 - Women exposed to trauma in their lives gave birth to underweight male infants
September 18, 2018 - Probiotic supplementation may reduce use of antibiotics, scientific analysis shows
September 18, 2018 - Resveratrol decreases pain severity and levels of inflammatory biomarkers in osteoarthritis patients
September 18, 2018 - Research shows pollution is reaching the placenta
September 18, 2018 - KAIST researchers develop heart-targeting drug delivery technology using tannin acid
September 18, 2018 - Muscle relaxants used during general anesthesia can increase risk of pulmonary complications
September 18, 2018 - Silicone breast implants may increase risk of rare adverse outcomes in women
September 18, 2018 - Pediatricians Have a Role in Encouraging Play Among Children
September 18, 2018 - California’s Medicaid program hits ‘print’ when the feds need info
September 18, 2018 - Genes, environment and schizophrenia—new study finds the placenta is the missing link
September 18, 2018 - Boehringer Ingelheim announces study results of COPD patients treated with Spiolto Respimat
September 18, 2018 - PAREXEL launches Patient Innovation Center to improve drug development process
September 18, 2018 - Children’s National and NIAID launch pediatric clinical research partnership
September 18, 2018 - Researchers may be overlooking complexities in social relations of primates
September 18, 2018 - Key signaling molecule that helps stem cells make healthy bone declines as we age
September 18, 2018 - More women veterans with chronic pain use CIH therapies than men
September 18, 2018 - As Earth Warms, Heat-Related Deaths Will Multiply
Study opens new window into cellular events that occur in the brain during absence seizures

Study opens new window into cellular events that occur in the brain during absence seizures

image_pdfDownload PDFimage_print

At first, the teacher described her six-year-old student as absentminded, a daydreamer. The boy was having difficulty paying attention in class. As the teacher watched the boy closely, she realized that he was not daydreaming. He often blanked out for a few seconds and wouldn’t respond when she called his name. On occasion, he would blink a lot and his eyes would roll up.

The teacher talked to the boy’s parents about his concerning behavior. His parents took him to the doctor and, after a few tests, he was diagnosed with absence epilepsy and prescribed medication. Absence epilepsy is the most common type of seizure disorders in children.

“In about 80 percent of children with absence seizures, the episodes usually stop around puberty. The other 20 percent will continue to have seizures,” said first and corresponding author Dr. Jochen Meyer, instructor of neurology and neuroscience at Baylor College of Medicine. “Absence seizures, even if they stop, are a disabling disorder because they cause children to be momentarily absent during periods of their formative years.”

“Many of these children also present with attention deficit disorder that can persist in about 40 percent of patients despite being treated with medication and even after the seizures stop,” said co-first author Dr. Atul Maheshwari, assistant professor of neurology and neuroscience at Baylor. “We need to have a better understanding of what happens in the brain during absence seizures.”

And that is what the researchers achieved in this study. They used a new technology called 2-photon microscopy that allowed them to visualize the firing activity of many individual neurons simultaneously in the brains of awake mice. They combined these observations with electroencephalograms that measured the electrical patterns of the same area of the brain. The results were completely unexpected.

‘It’s like listening to an orchestra without a conductor’

Researchers have known for decades that people having an absence seizure present with a typical electroencephalogram showing a spike-and-wave pattern of electrical activity that repeats for the duration of the seizure.

“The spike-and-wave pattern is very reproducible, and it’s during this period of time that the child would stop and stare. But nobody had studied what the brain cells themselves were doing during one of these episodes,” said co-author Dr. Jeffrey Noebels, professor of neurology, neuroscience, and molecular and human genetics and director of the Blue Bird Circle Developmental Neurogenetics Laboratory at Baylor.

The researchers took a closer look at the firing activity of neurons in an area of the visual cortex of a genetic mouse model of absence epilepsy. They used the new 2-photon microscopy technology to see the firing activity of many brain cells at the same time, in a way similar to people using Google maps to zoom in to look at a group of individual houses in a neighborhood.

“We had predicted from the spike-and-wave pattern of the brain waves that the behavior of the brain cells during a seizure also would be a rhythmical activity. Instead, we saw an uncoordinated firing activity, which was a big surprise,” said Noebels, who also holds the Cullen Endowed Chair in Neurogenetics. “It was always thought that during the ‘spike’ cells would fire, and during the ‘wave’ they would be quiet. That repeated pattern of spike-and-wave is the signature of this kind of epilepsy, so we assumed that it was based on the behavior of the cells that were generating the brain waves. But in fact we found that there appears to be no uniform connection between the cell behavior and the brain waves.”

“Normally the human brain, like an orchestra, is playing beautiful music and every player can understand what the others are playing. We thought that when a seizure started, the ‘orchestra of neurons’ would play extremely loud and intense music. And when the seizure ended, the neurons would go back to playing monotonous music,” Maheshwari said. “Instead, we found that during an absence seizure the volume of the music went down and the ‘musicians’ were playing music without coordinating with others. Most of them were not playing at all, as if the conductor was not there anymore. When the seizure ended, it was like the conductor had returned and organized the musicians to play harmoniously again.”

Interestingly, the reduction in brain cell activity began several seconds before the rhythmic spike-and-wave signature in the electroencephalogram started.

“It might be of interest in the future to further investigate whether the reduction in cellular activity that precedes the seizures could be used to predict them,” Meyer said.

The researchers’ contribution to the field of epilepsy has opened a window into the cellular events that occur in the brain during absence seizures.

“Now that we know that the ‘orchestra’ is disorganized, we can look for ways to treat the underlying causes of the seizures at the cellular level,” Maheshwari said.

Absence seizures can happen 100 times a day, but they are subtle and last only a few seconds, so they are often underdiagnosed or diagnosed late because they are easily mistaken for daydreaming.

Tagged with:

About author

Related Articles