Chorioamnionitis is an independent risk factor for cerebral palsy among term and near-term infants, according to a study published in the November 26 JAMA. A case-control study nested within a cohort of 231,582 singleton infants born at 36 or more weeks gestation in the Kaiser Permanente Medical Care Program in California found that chorioamnionitis was noted in 14% of cerebral palsy cases, compared with 4% of controls (odds ratio, 3.8). Independent risk factors for cerebral palsy included chorioamnionitis, intrauterine growth restriction, maternal black ethnicity, maternal age older than 25, and nulliparity, the researchers said.

Resveratrol, a compound found in grapes, can absorb free radicals released during a stroke and stop them from inflicting further damage to the brain and neurons. In an animal model, resveratrol was responsible for a “remarkable difference” between brain cells that had been treated with the compound and those that had not, investigators reported in the November Journal of Brain Research. The compound was helpful if taken both before and after a stroke. In addition to being found in enriched grape skins, resveratrol is present in high amounts in red wine, the researchers noted.

A novel model of human brain aging identified the midlife breakdown of myelin as a possible key to the onset of Alzheimer’s disease later in life. Detailed in the January Neurobiology of Aging, the model “shows that the brain’s wiring develops until middle age and then begins to decline as the breakdown of myelin triggers a destructive domino effect,” the investigators reported. Their analysis of MRI and postmortem tissue data suggests that genetic factors coupled with the brain’s own developmental process of increasing cholesterol and iron levels in middle age help degrade the myelin. The complex connections that take the longest to develop and allow humans to think at their highest level are among the first to deteriorate as the brain’s myelin breaks down in reverse order of development. According to the researchers, this new model of brain development and degeneration suggests that the best time to address the inevitability of myelin breakdown is when it begins, in middle age. By the time the effects of Alzheimer’s disease become apparent in a patient’s 60s, 70s, or 80s, it may be too late to reverse the course of the disease.

A protein related to maintaining long-term memory contains certain distinct prion signatures that may be key to its functioning, according to a study published as two papers in the December 26 Cell. The protein, CPEB, resides in central nervous system synapses and synthesizes other proteins that strengthen such synapses as memories are formed, enabling the synapses to retain those memories over long periods. Performing research in a sea slug, the researchers discovered that CPEB altered its form and caused other proteins to follow—functioning exactly like a prion. A second unexpected finding was that CPEB carried out protein synthesis when it was in its prion state—a finding that contradicts the notion that converting to a prion state is deleterious, the investigators reported. They postulated that in mammalian neuronal synapses, CPEB’s prion properties may be the mechanism that enables the synapses and nerve cells to store long-term memory and that further research will show prions themselves to be essential to many cellular functions.

People with McArdle’s disease can dramatically improve their exercise tolerance by consuming a soft drink or the equivalent thereof before physical activity. “By using an oral source of glucose—the equivalent of a soft drink—we show in this study that [patients with McArdle’s disease] are able to undertake exercise more easily, especially in the first eight to 10 minutes of physical activity. That’s important because it’s in that period that they are particularly vulnerable to muscle injury,” the researchers wrote. The study, published in the December 24 New England Journal of Medicine, is the first to measure the effect of oral glucose on exercise tolerance. Patients who drank a sugared cola 30 to 40 minutes prior to a 15-minute workout on a stationary bike had about a 30% increase in plasma glucose levels and no second wind (a hallmark of McArdle’s disease) compared to patients who received a placebo. But, during the seventh minute of exercise, the mean heart rate of cola-group patients was on average 34 beats per minute lower than patients who received the placebo, the investigators noted.

Persons who experience negative emotions like depression and anxiety that lead to psychological distress are twice as likely to develop Alzheimer’s disease than people who are less prone to experience distress, according to a study in the December 9 Neurology. The results, drawn from the Religious Orders Study, showed that proneness to stress was related to decline in episodic memory, which failed 10 times faster in those with high stress proneness compared to those with low stress proneness. However, proneness to distress was not related to measures of Alzheimer’s disease pathology, suggesting that proneness to distress is a risk factor for Alzheimer’s disease but not an early sign of the disease itself.

Researchers at Toronto Western Hospital and the University of Toronto have found a major mechanism that causes brain cells to die from stroke. In a study published in the December 26 Cell, the investigators reported that interfering with the activity of TRPM7—a channel on the surface of brain cells that initiates a lethal cascade of free radicals when the cells are deprived of oxygen—allows brain cells to survive for more than three hours without oxygen and vital nutrients. The failure of medications designed to block the effect of glutamate on N-methyl-D-aspartate receptors to reduce brain damage in humans paved the way for a return to the drawing board and this discovery that glutamate was only one part of the reason why brain cells die from stroke. With this new understanding, there is now an opportunity to develop new medications that prevent activation of the TRPM7 channel. It will take approximately three years to develop a medication, the researchers said.

Researchers have discovered a new pathway by which the bacterium Streptococcus pneumoniae—the most common cause of meningitis—enters the brain. “Our findings show bacteria enter the brain directly from the nasal cavity by way of olfactory nerves connecting the nasal and brain tissue,” the researchers reported in the November 25 Proceedings of the National Academy of Sciences. The investigators believe this finding could pave the way for the development of a new nasal vaccine to treat S pneumoniae infections.

Genetic factors contribute to Alzheimer’s disease that appears after age 80, but half or more of the susceptibility can be attributed to factors other than genes, according to a study in the December 15 online edition of Annals of Neurology. The report comes from a Swedish twin study, the first to look specifically at the relative contributions of genetics and environment in patients with late-onset Alzheimer’s disease, where individual genes do not appear to be at fault in causing the disease, as they are in early-onset Alzheimer’s disease. During an average five-year follow-up of 662 pairs of twins (ages 52 to 98), the investigators found that 5.8% of the study participants were diagnosed with Alzheimer’s disease. In 32.2% of identical twins, both twins developed the disease; among non-identical twins, this figure was only 8.7%. Using statistical modeling, the researchers determined that half or more of the susceptibility to Alzheimer’s disease in this cohort was attributable to environmental causes.

A small amount of a Parkinson’s disease–related neuronal protein, alpha-synuclein, can convince neighboring proteins to abandon their normal shape and form clusters contributing to cell death. Investigators showed that when alpha-synuclein was produced at low levels, it regulated chemical trafficking and metabolism of lipids in what appears to be normal functioning for this protein. However, when the levels of alpha-synuclein were slightly higher, the investigators found that some of the proteins misfolded and caused other proteins to do the same. The misfolded proteins began to form large clusters and the cell began to die, they reported in the December 5 Science. The researchers are hopeful that improving the quality of cellular control mechanisms that dispose of misfolded proteins might prove helpful in fighting Parkinson’s disease.

Deficiencies in the hippocampus play a key role in alcoholism-related Korsakoff’s syndrome, a memory disorder. These deficiencies are comparable to those found in the brains of patients with Alzheimer’s disease, according to a study in the December 23 Neurology. The amnesia of Korsakoff’s syndrome was believed to be rooted in the thalamus and other deep-brain structures, but researchers found otherwise. MRI comparisons of the brains of five men with Korsakoff’s syndrome, 20 men with Alzhiemer’s disease, and 36 healthy men showed that the brains of the patients with Korsakoff’s syndrome and those of the patients with Alzheimer’s disease were comparable in significant volume loss in the hippocampus. Greater hippocampal memory damage was correlated to higher memory deterioration for these patients.

Oxidation from free radicals can damage certain kinds of messenger RNA (mRNA) and may contribute to the onset of Alzheimer’s disease, according to a report at the 33rd Annual Meeting of the Society for Neuroscience. Using tissue from the brains of 11 recently deceased patients with Alzheimer’s disease, the investigators sought evidence of oxidative damage and mRNA content in the hippocampus, frontal cortex, and cerebellum. They compared their findings to seven age-matched control brains and two young subjects. The investigators found high levels of oxidative damage in the frontal cortex of only the Alzheimer’s patients’ brains; they also found that only certain species of mRNA are oxidized. Many of these mRNA were related to genes already known to be associated with Alzheimer’s disease, the researchers noted.

NR