“We were in a lot of fear and anxiety about this stuff,” said R. Kelly Brown, a neurosurgeon and director of clinical research at New York University.
“And so, for a lot, we were doing it in a very clinical way, with very little empathy or compassion for the patients or the families or the caregivers.”
And yet, he said, “we also knew that it was going to work.”
The study was published in the journal Neurobiology of Disease.
In the past, scientists have looked at whether certain mental illnesses can cause brain damage or brain injury, or both.
Researchers at Johns Hopkins University, led by neurosurgeons Richard O. Miller and Edward E. Fessler, also used data from a large study, called the NeuroGenome Project, which analyzed the genomes of more than 50,000 people with multiple genetic disorders.
The researchers were also using the data to examine how the brain and other organs respond to traumatic brain injury and how different types of brain damage might affect the people who had them.
In addition, they were looking at the effects of brain injuries on memory, thinking and behavior, and how brain injury can cause other neurological problems, such as cognitive impairment.
The Johns Hopkins team focused on the way certain genetic variations affect how people respond to stressors in different ways.
For instance, one genetic variation called APOE4 affects how susceptible people are to Alzheimer’s disease.
That variation has been associated with brain damage, as well as mental retardation.
But the scientists found that people with the APOE allele were at lower risk for cognitive impairment, so it wasn’t clear whether this was a consequence of cognitive impairment or the effects on cognition.
“I was trying to understand why we might be able to detect this difference in cognition,” said Dr. Miller, who is now an associate professor of neurology at Johns Wayne State University.
They also wanted to understand whether the APOE allele affects the way the brain interacts with other brain cells.
The team took samples of brain cells from a group of people with APOE2, the variant that produces less of the enzyme, APOE3, that breaks down a chemical called GABA.
The scientists took DNA from the cells and sequenced the DNA to look for the AP2 gene.
They found that the DNA from people with a higher proportion of APOE alleles had higher levels of the chemical that is broken down by GABA, which is also produced by neurons in the brain.
In some people with more APOE1, people with Alzheimer’s have less GABA.
So, this increased release of GABA can cause people with mild cognitive impairment to be more vulnerable to Alzheimer.
In another experiment, the researchers took cells from people who were experiencing symptoms of Alzheimer’s, and used them to look at how brain cells are damaged.
They examined the brains of people who developed Alzheimer’s and compared them to those of healthy people, who had no symptoms of dementia.
The people who tested positive for the disease were more likely to have a mutation in a gene called APO1, and they also had a higher risk of developing cognitive impairment as a result of Alzheimer.
“These are all different things that you can look at with a brain,” Dr. Osterman said.
“You can look for genetic changes in brain function, which could mean that you are less sensitive to stress or to stress-related changes in the environment.
You can also look at whether there is a particular way in which these brain cells respond to other cells.”
Dr. Fultz, who led the team that studied APOE, said one of the ways they might look at the AP1 mutation is to look to see if it is affecting how the cells in the nervous system react to stress.
That would help explain why some people are more susceptible to brain damage and how it can affect memory, he added.
The APOE mutation could also have other effects on the brains that are different from those of people without it.
One type of genetic variation that causes APOE affects how the protein, AMP-activated protein kinase, interacts with neurons in cells.
This protein is part of the signaling system that helps neurons make connections and learn.
But because APOE is a gene, it affects other genes in a similar way, Dr. Smith said.
The fact that there is more APO-2 in people with high levels of APO has been linked to Alzheimer, Dr, Smith said, because the higher levels are associated with more problems in the memory and behavior of people in this group.
The results of the Johns Hopkins study were not meant to be definitive.
“It’s a hypothesis,” Dr Miller said.
But, he cautioned, the findings could be useful in developing drugs to help people with these disorders, and could help doctors better understand how to treat them.
“This is an important question,” he said.
Dr. Brown, the Johns Wayne