Nitrous oxide may bring relief to veterans suffering from PTSD

July 7, 2020

Science Daily/University of Chicago Medical Center

A small pilot study provides an early glimpse of how some veterans struggling with PTSD may benefit from one simple, inexpensive treatment involving nitrous oxide, commonly known as laughing gas.

For military veterans suffering from post-traumatic stress disorder (PTSD), symptoms such as anxiety, anger and depression can have a devastating impact on their health, daily routine, relationships and overall quality of life.

A new pilot study by the University of Chicago Medicine and the Stanford University School of Medicine team from the VA Palo Alto Health Care System (principal investigators Carolyn Rodriguez, MD, and David Clark, MD, PhD) provides an early glimpse of how some of these veterans may benefit from one simple, inexpensive treatment involving nitrous oxide, commonly known as laughing gas.

"Effective treatments for PTSD are limited," said anesthesiologist Peter Nagele, MD, chair of the Department of Anesthesia & Critical Care at UChicago Medicine and co-author of the paper. "While small in scale, this study shows the early promise of using nitrous oxide to quickly relieve symptoms of PTSD."

The findings, based on a study of three military veterans suffering from PTSD and published June 30 in the Journal of Clinical Psychiatry, could lead to improved treatments for a psychiatric disorder that has affected thousands of current and former members of the U.S. military.

For this new study, three veterans with PTSD were asked to inhale a single one-hour dose of 50% nitrous oxide and 50% oxygen through a face mask. Within hours after breathing nitrous oxide, two of the patients reported a marked improvement in their PTSD symptoms. This improvement lasted one week for one of the patients, while the other patient's symptoms gradually returned over the week. The third patient reported an improvement two hours after his treatment but went back to experiencing symptoms the next day.

"Like many other treatments, nitrous oxide appears to be effective for some patients but not for others," explained Nagele, who is himself a veteran of the Austrian Army and grateful to have identified an opportunity to help other veterans. "Often drugs work only on a subset of patients, while others do not respond. It's our role to determine who may benefit from this treatment, and who won't."

Nagele is a pioneer in the field of using nitrous oxide to treat depression. Most commonly known for its use by dentists, nitrous oxide is a low-cost, easy-to-use medication. Although some patients may experience side effects like nausea or vomiting while receiving nitrous oxide, the reactions are temporary.

Exactly how and why nitrous oxide relieves symptoms of depression in some people has yet to be fully understood. Most traditional antidepressants work through a brain chemical called serotonin. Nitrous oxide, like ketamine, an anesthetic that recently received FDA-approval in a nasal spray form to treat major depression, works through a different mechanism, by blocking N-methyl-D-aspartate (NMDA) receptors.

A 2015 landmark study by Nagele found that two-thirds of patients with treatment-resistant depression experienced an improvement in symptoms after receiving nitrous oxide.

For his next study, Nagele is researching the ideal dose of nitrous oxide to treat intractable depression. Study participants with treatment-resistant depression received different doses of nitrous oxide so that Nagele and his team could compare each dose's effectiveness and side effects. The study is being funded by the Brain & Behavior Research Foundation.

"Does nitrous oxide help veterans with post traumatic stress disorder" was funded by the VA Office of Research and Development Clinical Science Research & Development Service.

https://www.sciencedaily.com/releases/2020/07/200702113647.htm

Alzheimer's: Can an amino acid help restore memories?

March 3, 2020

Science Daily/CNRS

Scientists at the Laboratoire des Maladies Neurodégénératives (CNRS/CEA/Université Paris-Saclay) and the Neurocentre Magendie (INSERM/Université de Bordeaux) have just shown that a metabolic pathway plays a determining role in Alzheimer's disease's memory problems. This work, published on 3 March 2020 in Cell Metabolism, also shows that supplying a specific amino acid as a nutritional supplement in a mouse model of Alzheimer's restores spatial memory affected early. This is a promising path for reducing memory loss related to that disease.

The brain uses a large part of the energy available to our body. To work properly, neurons and the surrounding cells, particularly astrocytes, must cooperate. The early phase of Alzheimer's disease is characterized by a reduction in this energy metabolism, but until now we did not know whether this deficit contributed directly to the cognitive symptoms of Alzheimer's disease.

A collaborative study has shown in a mouse model of Alzheimer's disease that a decrease in the use of glucose by astrocytes reduces L-serine production. This amino acid is mainly produced by these brain cells and its biosynthesis path is altered in patients. L-serine is the precursor of D-serine, known to stimulate NMDA receptors, essential for brain function and to the establishment of memory. So by producing less L-serine, astrocytes cause reduced activity in these receptors, which alters neuronal plasticity and the associated memorization capacities. Scientists have also demonstrated that memorization functions in mice were restored by supplying nutritional L-serine.

With the identification of the role of L-serine in memory disorders and the experimental efficacy of nutritional supplementation, new strategies appear that may complement medical treatment, to combat early symptoms of Alzheimer's disease and other diseases that display metabolic deficits, like Parkinson's and Huntington's. Since L-serine is available as a nutritional supplement, this compound should be rigorously tested in humans, through controlled clinical trials.

https://www.sciencedaily.com/releases/2020/03/200303113357.htm