Lorena

Lorena
St. Mary’s School

Mentor: 
Nolan Hartley
Stanley Center for Psychiatric Research

 

Lorena spent her BSSP summer investigating how the brain's sensory-control circuitry takes shape during early development. She focused on the thalamic reticular nucleus (TRN), a layer of inhibitory neurons surrounding the thalamus that helps control information traveling between the thalamus and cerebral cortex. Through this role, the TRN contributes to sensory processing, attention, learning, and sleep.

Previous work in the Fu Lab identified two genetically distinct TRN populations. Neurons expressing Spp1 primarily occupy the TRN core and connect with first-order thalamic pathways, while Ecel1-expressing neurons form a shell associated with higher-order pathways. Lorena and Arya set out to determine when this core-and-shell organization first becomes established during postnatal development.

Lorena used HCR-FISH, a fluorescence-based technique that allows researchers to locate specific RNA molecules within intact tissue. Her workflow involved preparing brain tissue, washing and permeabilizing samples, probe hybridization, fluorescent signal amplification, microscopy, and quantitative analysis. She then mapped Spp1- and Ecel1-expressing neurons along the anterior-posterior axis and examined how frequently the two markers appeared in the same cells.

The team's results showed that the two genetically defined subnetworks emerge before the second postnatal week (P14) and remain largely segregated throughout the developmental stages examined. Early analyses suggest that overlap between the populations may change with age, although additional samples are needed before drawing firm conclusions.

Lorena learned how fluorescent RNA detection and anatomical mapping can be used to follow the emergence of genetically distinct neural populations across development.
Lorena's work provides a developmental map for an important neural circuit and opens a new question: whether these subnetworks develop according to a predetermined genetic program or require sensory experience. Future experiments manipulating external sensory input will help distinguish between those possibilities.

Upon reflecting on her time in the program Lorena said “BSSP taught me the importance of collaboration in a scientific environment. It was an incredible experience that gave me a real-life glimpse of what my life could look like in the future as a woman in a STEM field”.