Study finds ‘important implications’ to understanding immunity against COVID-19

New research from Emory University indicates that nearly all people hospitalized with COVID-19 develop virus-neutralizing antibodies within six days of testing positive. The findings will be key in helping researchers understand protective immunity against SARS-CoV-2 and in informing vaccine development. The test that Emory researchers developed also could help determine whether convalescent plasma from COVID-19 survivors can provide immunity to others, and which donors' plasma should be used. The antibody test developed by Emory and validated Read more

Emory plays leading role in landmark HIV prevention study of injectable long-acting cabotegravir

Emory University played a key role in a landmark international study evaluating the safety and efficacy of the long-acting, injectable drug, cabotegravir (CAB LA), for HIV prevention. The randomized, controlled, double-blind study found that cabotegravir was 69% more effective (95% CI 41%-84%) in preventing HIV acquisition in men who have sex with men (MSM) and transgender women who have sex with men when compared to the current standard of care, daily oral emtricitabine/tenofovir disoproxil fumarate Read more

Yerkes researchers find Zika infection soon after birth leads to long-term brain problems

Researchers from the Yerkes National Primate Research Center have shown Zika virus infection soon after birth leads to long-term brain and behavior problems, including persistent socioemotional, cognitive and motor deficits, as well as abnormalities in brain structure and function. This study is one of the first to shed light on potential long-term effects of Zika infection after birth. “Researchers have shown the devastating damage Zika virus causes to a fetus, but we had questions about Read more

Jessica Raper

Yerkes researchers find Zika infection soon after birth leads to long-term brain problems

Researchers from the Yerkes National Primate Research Center have shown Zika virus infection soon after birth leads to long-term brain and behavior problems, including persistent socioemotional, cognitive and motor deficits, as well as abnormalities in brain structure and function. This study is one of the first to shed light on potential long-term effects of Zika infection after birth.

“Researchers have shown the devastating damage Zika virus causes to a fetus, but we had questions about what happens to the developing brain of a young child who gets infected by Zika,” says lead researcher Ann Chahroudi, MD, PhD, an affiliate scientist in the Division of Microbiology and Immunology at Yerkes, director of the Center for Childhood Infections and Vaccines (CCIV), Children’s Healthcare of Atlanta (CHOA) and Emory University, and an associate professor of pediatrics in the Division of Pediatric Infectious Diseases at Emory University School of Medicine.

“Our pilot study in nonhuman primates provides clues that Zika virus infection during the early postnatal period can have long-lasting impact on how the brain develops and works, and how this scenario has the potential to impact child behavior,” Chahroudi continues.

The study, published online in Nature Communicationsfollowed four infant rhesus monkeys for one year after Zika virus infection at one month of age. Studying a rhesus monkey until the age of 1 translates to the equivalent of 4 to 5 years in human age. Researchers found postnatal Zika virus infections led to Impairments in memory function, significant changes in behavior, including reduced social interactions and increased emotional reactions, and some gross motor deficits. These changes corresponded with structural and functional brain changes the researchers found on MRI scans – findings that indicate long-term neurologic complications.

“Our findings demonstrate neurodevelopmental changes detected at 3 and 6 months of age are persistent,” says first author Jessica Raper, PhD, research assistant professor at Yerkes. (See Science Translational Medicine for an earlier study by members of the current research team.) “This is significant because it gives healthcare providers a better understanding of possible complications of Zika beyond infection during pregnancy and into the first years of life,” she adds.
Read more

Posted on by Wayne Drash in Neuro Leave a comment

Designer drugs as tools for studying brain development in non-human primates

To investigate the functions of regions within the brain, developmental neuroscience studies have often relied on permanent lesions. As an alternative to permanent lesions, scientists at Yerkes National Primate Research Center sought to test whether chemogenetic techniques could be applied to produce a transient inhibition of the amygdala, well known for regulating emotional responses, in infant non-human primates.

Their findings were recently published online by eNeuro, an open access journal of the Society for Neuroscience.

Amygdala — image from NIMH

Chemogenetics is a way of engineering cells so that they selectively respond to designer drugs, which have minimal effects elsewhere in the brain. It involves injection of a viral vector carrying genes encoding receptors responsive to the designer drug – in this case, clozapine-N-oxide, a metabolite of the antipsychotic clozapine. The technique has mostly been tested in rodents.

“This proof-of-principle study is the first to demonstrate that chemogenetic tools can be used in young infant nonhuman primates to address developmental behavioral neuroscience questions,” says Jessica Raper, PhD, first author of the eNeuro paper and a research associate at Yerkes. “Considering its reversibility and reduced invasiveness, this technique holds promise for developmental studies in which more invasive techniques cannot be employed.” Read more

Posted on by Quinn Eastman in Neuro Leave a comment

Neuroscientists show hippocampus also has important role in emotional regulation

A region of the brain called the hippocampus is known for its role in memory formation. Scientists at Yerkes National Primate Research Center, Emory University are learning more about another facet of hippocampal function: its importance in the regulation and expression of emotions, particularly during early development.

Using a nonhuman primate model, their findings provide insight into the mechanisms of human psychiatric disorders associated with emotion dysregulation, such as PTSD (post-traumatic stress disorder) and schizophrenia. The results were published online recently by the journal Psychoneuroendocrinology.

“Our findings demonstrate that damage to the hippocampus early in life leads to increased anxiety-like behaviors in response to an unfamiliar human,” says research associate Jessica Raper, PhD, first author of the paper. “However, despite heightened anxious behavior, cortisol responses to the social stress were dampened in adulthood.”

The hormone cortisol modulates metabolism, the immune system and brain function in response to stress. Reduced hippocampal volume and lower cortisol response to stressors have been demonstrated as features of and risk factors for PTSD, Raper says. Also, the dampened daily rhythms of cortisol seen in the nonhuman primates with hippocampal damage resemble those reported in first-episode schizophrenia patients.

Follow-up studies could involve temporary interference with hippocampus function using targeted genetic techniques, she says. Read more

Posted on by Quinn Eastman in Neuro Leave a comment

HD monkeys display full spectrum of symptoms seen in humans

Transgenic Huntington’s disease monkeys display a full spectrum of symptoms resembling the human disease, ranging from motor problems and neurodegeneration to emotional dysregulation and immune system changes, scientists at Yerkes National Primate Research Center, Emory University report.

The results, published online in the journal Brain, Behavior and Immunity, strengthen the case that transgenic Huntington’s disease monkeys could be used to evaluate emerging treatments (such as this) before launching human clinical trials.

“Identifying emotional and immune symptoms in the HD monkeys, along with previous studies demonstrating their cognitive deficits and fine motor problems, suggest the HD monkey model embodies the full array of symptoms similar to human patients with the disease,” says Yerkes research associate Jessica Raper, PhD, lead author of the paper. Read more

Posted on by Quinn Eastman in Neuro Leave a comment

Maturing brain flips function of amygdala in regulating stress hormones

In contrast to evidence that the amygdala stimulates stress responses in adults, researchers at Yerkes National Primate Research Center, Emory University have found that the amygdala has an inhibitory effect on stress hormones during the early development of nonhuman primates.

The results are published this week in Journal of Neuroscience.

The amygdala is a region of the brain known to be important for responses to threatening situations and learning about threats. Alterations in the amygdala have been reported in psychiatric disorders such as depression, anxiety disorders like PTSD, schizophrenia and autism spectrum disorder. However, much of what is known about the amygdala comes from research on adults.

“Our findings fit into an emerging theme in neuroscience research: that during childhood, there is a switch in amygdala function and connectivity with other brain regions, particularly the prefrontal cortex,” says Mar Sanchez, PhD, neuroscience researcher at Yerkes and associate professor of psychiatry and behavioral sciences at Emory University School of Medicine. The first author of the paper is postdoctoral fellow Jessica Raper, PhD.

Some notable links on the amygdala:

*An effort to correct simplistic views of amygdala as the “fear center” of the brain

*Collection of papers mentioning patient SM, an adult human with an amygdala lesion

*Recent Nature Neuroscience paper on amygdala’s role in appetite control

*Evidence for changing amygdala-prefrontal connectivity in humans during development Read more

Posted on by Quinn Eastman in Neuro Leave a comment