The Crocker Lab is interested in understanding what happens at the molecular and cellular levels in the brain when an animal experiences a painful traumatic event. And in turn, how this changes behavior. We are interested in understanding why painful events are often our strongest memories and why they are so hard to forget. This work has relevance to our understanding of Post-Traumatic Stress Disorder (PTSD) and Traumatic Brain Injuries (TBI). We want to know what happens at a cellular level when the brain goes through a physically painful experience, either through exposure to electric shock or severe mechanical pain. In order to study how this changes the molecular and cellular properties of neurons, as well as behavior, we use the fruit fly (Drosophila melanogaster) as a model organism. The fruit fly has a rich history in genetics with a number of Nobel prizes awarded for work using it to understand development, and most recently circadian rhythms.

Cell signaling gene expression across different populations of Drosophila melanogaster neurons.

The Crocker Lab uses behavioral genetics techniques (RNAseq and GWAS) to look for genes that may play a role in the brain’s response to painful stimuli. We use this information to then examine specific genes and the role they play in behavior. We are also interested more generally in what physically painful events do to behavior. In particular to exploratory behavior, memory, stress, and to social interactions. We use a video tracking program that allows us to follow individual flies as they move and interact with other flies in large circular arenas. This allows for fine quantitative analysis of behavior as well as for high throughput in the number of animals tested.

Video tracking of 15 flies for 5 minutes. The top half of the chamber is over an electrified grid. On the left is are animals that do not avoid the shock and on the right is are animals that do.

Larval sensory neurons along the body wall of 3rd instar larvae.

The lab has the capacity to map at a circuit level where these genes may be influencing behavior and what neurons are involved in the integration of painful stimuli. This can be done through immunostaining (labeling proteins of interest). We can also track through calcium signaling what neuronal activity looks like following exposure to painful stimuli. Both immunostaining and calcium imaging allow us to address potential changes in cellular architecture and circuitry due to exposure to painful stimuli.

We have recently started collaborating with Dr. Victor Faundez at Emory University. Through this collaboration we are bring cutting edge sequencing and bioinformatics projects to Middlebury students. The data sets we are analyzing are important for our understanding of the roles certain genes and mutations play in neurological disorders. They provide insights into how the transcriptional and proteomic landscape shapes complex neurological disorders such as Rett’s syndrome.