News

Armond Collins, a second year medical student, presents the study he conducted with us this summer under the auspices of a Babigian Fellowship. Armond studied changes in myelination in amygdala and cortex of adult rats that had been exposed to 3 day bout of a repeated variable stressor during adolescence. His works follows up studies by Michele Saul, PhD that indicate that adolescent stress results in decreased oligodendrocyte precursors in the amygdala in the week following the stress.

Congratulations to Ashley Bui, a rising senior in Brain and Cognitive Sciences, on her presentation July 22, 2016. Her talk Projections from the Temporal Cortex to the Basal Nucleus of the Amygdala in the Macaque highlighted data from her summer project in our lab. The amygdala is required for computing which of the complex sensory stimuli that an individual encounters are emotionally meaningful, so that appropriate action can be taken. Ashley’s preliminary data shows that specific portions of the temporal cortex, which are critical for processing complex visual and auditory information, communicate with different regions of the amygdala. The results suggest that cortical areas that process complex visual information on 'what' and 'where' an object is (or is moving) are communicating with specific amygdala subregions. Thus, while determining the emotional importance of ‘what or who’ is important, biologic movements also likely influence amygdala activity and coding. We are happy that she will continue this work through the Fall semester.

Congratulations to Julia on winning a Professors’ Choice Award in Natural Sciences at last Friday’s Undergraduate Research Exposition on the River campus. The exposition highlighted undergraduate work in Humanities, Social Science, Natural Science, and Engineering. A Professors’ Choice award was given to a poster presentation in each discipline.

UR senior, Julia Iourinets, will present her work on April 22 at 2pm in the Rush Rhees Library Hawkins-Carlson Room. Her work examining differential hippocampal inputs to key nodes of the extended amygdala is the product of two semesters of Independent Study in our lab. This work was also presented at the Society for Neuroscience 2015 Annual Meeting. Please visit her poster and hear her formulation of her work!

Congratulations to Armond, a first year medical student, for winning a Babigian Fellowship, a summer research award through the Department of Psychiatry. Armond's proposed research entitled Effects of Adolescent Stress on Myelin Formation in Rat Amygdala builds on findings developed by Dr. Michele Saul, a former graduate student in the laboratory. Michele found changes in oligodendrocyte precursor numbers in adolescent animals shortly after a relatively mild stressor. This summer Michele will take time to return to the laboratory to advise and work with Armond on learning whether this effect has lasting consequences on myelin formation in the adult.

We congratulate Danielle on her match, where she will start the next phase of her training as a Resident in Child Neurology. In addition to excellent clinical training at JHU, Danielle will interact with researchers at the Kennedy-Krieger Institute, an NIH-funded center for the study of Intellectual and Developmental Disorders. Danielle’s thesis An Extended Amygdala Pathway for Effects of Early Life Stress examined cellular and molecular consequences of maternal deprivation in nonhuman primate amygdala. We know that she will take her perspective on the developing limbic system to the next level in Baltimore. Best wishes!

New research shows that our brains may be hardwired to become sensitive to stressful environments at an early age and, if overstimulated, this may contribute to anxiety disorders and even psychotic syndromes later in life.

The study, which appears in the journal Brain Structure and Function, focuses on two structures deep in the brain. The central nucleus of the amygdala (Ce) is thought to be involved in responses to immediate threats and stimulus, such as becoming startled or freezing in reaction to a loud noise. The bed nucleus of the stria terminalis (BST) is thought to be involved in regulating a person’s state of vigilance, such as determining whether or not an environment or a situation poses a potential threat. Animal and human studies show that when the BST is activated by a threatening situation, we tend to slow down, become quieter, and stress hormones spike.

While Ce and BST reside in different parts of the brain, the two areas are hardwired to each other by axonal tracts – basically, bundles of long distance axon fibers that enable the separate regions to communicate with each other. However, until now it has not been clear when these connections form or the way in which they interact with each other.

In the study published today, a team of researchers led by Julie Fudge, M.D., with the Department of Neuroscience observed that these connections are made at a very early stage of development in non-human primates. They also found that the direction of the connection is essentially a one way street. The Ce – or immediate fear signaling center – conveys information to the BST, the structure that mediates general threat sensing or anxiety states. This arrangement suggests that repeated activation of the Ce by immediately fearful or traumatic events may shape long-term anxiety states in the BST.