There is no shortage of wonders that our central nervous system produces—from thought and language to movement to the five senses.
All of those dazzling traits, however, depend on an underappreciated deep brain mechanism that Donald Pfaff, head of the Laboratory of Neurobiology and Behavior at The Rockefeller University, calls generalized arousal, or GA for short. GA is what wakes us up in the morning and keeps us aware and in touch with ourselves and our environment throughout our conscious hours.
“It’s so fundamental that we don’t pay attention to it,” says Pfaff, “and yet it’s so important that we should.”
Pfaff and his team of researchers certainly do. Now, in a series of experiments involving a particular type of brain cell, they have advanced our understanding of the roots of consciousness. Their work may potentially prove relevant in the study of some psychiatric diseases.
The big cells in the black box
The findings, published this month in Proceedings of the National Academy of Sciences, shed light on an area of the brainstem that is so little understood the first author of the paper, Inna Tabansky, a research associate in Pfaff’s lab, calls it “the black box.” That term is certainly simpler than its actual name—the nucleus gigantocellularis (NGC), which is part of a structure called the medullary reticular formation.
In her work, using mice, Tabansky focused on a subtype of extremely large neurons in the NGC with links to virtually the entire nervous system, including the thalamus, where neurons can activate the entire cerebral cortex. “If you just look at the morphology of NGC neurons, you know they’re important,” Pfaff says. “It’s just a question of what they’re important for. I think they’re essential for the initiation of any behavior.”
To discover what role the NGC neurons might play in GA, Tabansky and her colleagues, including Joel Stern, a visiting professor in the Pfaff lab, began by identifying the genes that these neurons express. They used a technique known as “retro-TRAP,” developed in the lab of Rockefeller scientist Jeffrey Friedman.
To Tabansky’s surprise, the NGC neurons were found to express the gene for an enzyme, endothelial nitric oxide synthase (eNOS), which produces nitric oxide, which in turn relaxes blood vessels, increasing the flow of oxygenated blood to tissue. (No other neurons in the brain are known to produce eNOS.) They also discovered that the eNOS-expressing NGC neurons are located close to blood vessels.
In Pfaff’s view, the neurons are so critical for the normal functions of the central nervous system that they have evolved the ability to control their own blood supply directly. ‘“We’re pretty sure that if these neurons need more oxygen and glucose, they will release nitric oxide into these nearby blood vessels in order to get it,” he says.
The circumstances that would prompt such a response were the subject of further experiments. The scientists found evidence that changes in the environment, such as the introduction of novel scents, activated eNOS in the NGC neurons and produced increased amounts of nitric oxide in mice.
“There is some low level of production when the animal is in a familiar setting,” says Tabansky, “which is what you expect as they maintain arousal. But it is vastly increased when the animal is adapting to a new environment.” This activation of the NGC neurons supports the case for their central role in arousal, Tabansky says.
From cells to psychiatry
Going forward, Tabansky says she’s interested in exploring if their findings might help fill a gap in the understanding of certain disorders, such as bipolar disorder, suicidality, and ADHD. Some genetic research has implicated a role for the neurons she studied in these diseases, but the mechanism behind this link is not known.
“By showing that this gene and its associated pathways have a particular role, at least in the rodent brain, that relates to a fundamental function of the nervous system, is a hint about how this gene can cause psychiatric disease,” she says. “It’s very preliminary, and there is a lot more work to be done, but it potentially opens a new way to study how this gene can alter an individual’s psychology.”
The Latest on: Psychiatric diseases
via Google News
The Latest on: Psychiatric diseases
- Transgender students more prone to mental health disorderson August 16, 2019 at 10:50 pm
It used clinically validated methods of screening for symptoms of depression, anxiety, eating disorders, and other mental health concerns and conducted ... that there is a large and disproportionate ...
- Montera: How we’re helping combat mental health crisison August 16, 2019 at 3:37 pm
To understand that our country is facing a mental health crisis, you only have to look to our youngest ... according to studies by the Centers for Disease Control and Prevention. While our idyllic ...
- Why it’s wrong to blame mass killings on mental illnesson August 16, 2019 at 9:13 am
Or, as he has taken to calling people with psychiatric disease, “mentally ill monsters.” (He’s also referred to “nut jobs,” “lunatics,” and “wackos.”) Trump, reading to Americans from a teleprompter, ...
- A version of 911 specifically for mental health crises could be coming soonon August 16, 2019 at 8:59 am
Suicide is a huge problem in the United States—the Center for Disease Control and Prevention (CDC ... dedicated solely for the purpose of a national suicide prevention and mental health hotline would ...
- Why the Government should address mental disorders urgentlyon August 16, 2019 at 12:47 am
infectious diseases, and marital conflicts, failing to apply interventions on mental health illnesses by the government is like waiting for a time bomb to explode. It must be remembered that ...
- Transgender college students four times as likely to experience mental health problemson August 15, 2019 at 11:56 pm
"Mental health outcomes, as well as negative educational ... population that already experiences a disproportionate burden of disease," says Raifman, referring to recent actions initiated by ...
- Holland schools, hospital pilot mental health care manager to prevent suicideson August 15, 2019 at 2:14 pm
“This is contributing to severe mental anxiety and risk for self-harm ... s School Nurse Program has provided onsite direct medical support, prevention, chronic disease management and referrals for ...
- Stop blaming mental illnesson August 15, 2019 at 12:30 pm
Mental illnesses, certainly severe mental illnesses ... largely because of a dearth of public funding for this line of research. The U.S. Centers for Disease Control and Prevention (CDC) had ...
- Having a mental health crisis? Dial 988on August 15, 2019 at 9:45 am
From not having kids to battling anxiety: Climate change is affecting mental health Mental health ... according to the Centers for Disease Control and Prevention. There were 45,000 deaths in 2016. The ...
via Bing News