Brain and Behavior
Additional topics are available in Updates by Chapter.

Toward A New Drug for Alzheimer's
Results of a Phase 3 (clinical effectiveness) trial of aducanumab (see p 365 of your text) aren't expected until 2020; in the meantime, BAN2401 is showing highly promising results in both removing plaques and slowing cognitive decline. In patients receiving the highest dose, amyloid levels dropped below the dementia threshold and cognitive ability declined 30% slower than in the placebo group. The results were presented at the 2018 Alzheimer's Association International Conference. New York Times, July 25, 2018.

How Far Can Gene Editing Go?

Recently a biochemist injected himself with DNA edited to remove the gene for myostatin, which regulates muscle growth, with the intent of boosting his strength. Now he is selling a kit with instructions for using the CRISPR gene editing technique so the user can do the same thing. New Scientist, Nov 18, 2017, 22-23. Of course, this raises significant ethical questions, but proponents argue that a person has the right to alter his or her own genes. That argument won't fly with the World Anti-Doping Agency, which sets standards for over 600 sports organizations, including the International Olympic Committee. WADA has revised its list of banned substances and techniques to prohibit gene editing and alterations of gene expression. New Scientist, Oct 14, 2017, 4.

Hyperbaric Oxygen for Treating Concussion
Although an estimated one-quarter of military personnel serving in Iraq and Afghanistan sustained head injuries and there were 244 concussions among NFL players in 2016, there is no FDA approved treatment for concussion. Evidence is beginning to accumulate that numerous sessions of breathing pure oxygen in a pressurized chamber improves cognitive functioning and quality of life. Using MRI, researchers at Tel Aviv University found that in patients treated six months to 27 years after injury hyperbaric oxygen stimulated regrowth of neural fibers by 7% and blood vessels by 5% in brain regions involved in information processing and memory. Frontiers in Human Neuroscience, (online).

Zeroing in on Male Homosexuality
A Canadian team has found evidence to explain the &quotOlder Brother" effect in male homosexuality, and other researchers have identified three new gene areas related to male sexual orientation. See the updates for Biology of Sex and Gender.

Court Orders EPA to Ban Chlorpyrifos on Farms
A U.S. federal court has given the EPA 60 days to ban agricultural use of chlorpyrifos, a
neurotoxic pesticide. See the updates for Intelligence and Cognitive Functioning.

Gene Identified That Protects Against Brain Disease
Buildup of harmful proteins in the brain can lead to neurological diseases, such as Parkinson's and Alzheimer's. Now University of California - San Diego scientists have identified a gene that helps prevent the protein buildup. Ordinarily, errors in transfer RNA are corrected before proteins are synthesized, but if this proofreading fails it can result in production of the amino acid serine, which is then incorporated into proteins and causes protein aggregation. The gene ANKRD16 directs production of the ANKRD16 protein, which captures serine and reduces protein accumulation. Deleting the ANKRD16 gene in mice genetically predisposed to the transcription error results in increased protein buildup and neuronal death, while increasing the level of the ANKRD16 protein protects against cell death. Nature, Vol 557, 510-515.

Judgement Depends on Connectivity of Prefrontal Cortex With Striatum
It's well known that judgements about value and risk depend on development of the prefrontal cortex, but a recent study has added to that understanding. Volunteers aged 13 to 20 years played a game in which they were to press a button to one version of a stimulus and withhold response to a slightly different one; correct responses were rewarded with 20 cents under the low stakes condition and $1 under the high stakes condition. Ordinarily we would expect performance to improve when larger rewards are available, but this was the case only among the 19-20 year-olds. Scanning with fMRI showed that better performance was associated with increased activity in the prefrontal cortex and more powerful connections with subcortical striatal areas. In other words, differential reward was poor at regulating behavior in the younger individuals, apparently in part because they were less able to access reward information, which helps explain why rewards and punishments are not very effective with teens. Nature Communications, Vol 8, #1605 (online).

Decoding the Genetics of Disorders
Researchers have recently identified forty four genes linked with depression and four obsessive-compulsive genes, determined fifty new schizophrenia gene locations, and demonstrated shared patterns of gene expression across disorders. See the updates for Psychological Disorders.