Sabrina Santos de León
Undergraduate Student
Faculty of Natural Sciences
Dept. Celular & Molecular Biology
University of Puerto Rico
Río Piedras Campus
Home Research
Mentor: Carmen S. Maldonado-Vlaar, PhD (UPR-Rio Piedras Campus)
Project: The role of the endocannabinoid system in Lipopolysaccharide-induced depression and its effect on the insular cortex
Project Description: Previous studies have demonstrated a close association between an altered immune system and major depressive disorders. Altered cytokines have been shown to lead synaptic degeneration and neuronal cell death, providing a strong association between cytokine dysregulation and neuroinflammation-linked depression (Song and Wang, 2011). Lipopolysaccharide (LPPS) injections can trigger and facilitate proinflammatory cytokine production (Kassan et al., 2013). Several studies have found that the endogenous cannabinoid system (eCs) through anandamide (AEA) alteration, may help modulate neuronal and immune cell function, playing a role in neuroinflammation. Given that the insular cortex is an information integration center in the brain, it is surprising that its role has not yet been studied in neuroinflammatory-induced depression. In our study we aim to determine the role of the insula after AEA increase through a FAAH inhibitor after LPPS induced inflammation in rats. We hypothesize that, because of its neuroprotective role, rats with AEA increase will show less depressive and anxious behaviors compared to those who were exposed to the neuroinflammatory-induced depression. This will shed light on the role of the insular cortex and its collaboration with the endocannabinoid system on the regulation of depressive-like behaviors after a neuroinflammatory response.
Mentor: Christian Bravo (UPR Medical Sciences Campus)
Project: Sex differences in reward approach and avoidant behaviors in mice.
Project Description: Evaluate behavioral data through an in-depth analysis, of mice in a platform mediated avoidance task (PMA). Characterized significant differences in these reward approach and avoidant behaviors depending on the sex of the animal. This behavioral data caved a path in order to characterize physical differences in circuitry (specifically involving the BLA) present in both males and females in order to account for these behavioral differences.
Summer Research
Mentor: Sam McDougle (Yale University)
Project: Hierarchical Processing and Memory Encoding
Description of Project: Hierarchical processing of daily events is crucial for carrying out daily tasks. Studies of event segmentation show memory encoding is enhanced at event boundaries (Egner et al., 2022). Task switching literature indicated impaired memory encoding at the moment of hierarchical control (Mejer, B. et al 2019). Given this conflicting evidence regarding memory encoding at moments of hierarchical processing, we will be operationalizing complicated task sequences that we complete in daily life with simple four-item task sequences comprised of two simple tasks. During trials, subjects will have to respond only to one aspect of the compound stimulus: and indoor-outdoor judgment of a scene and an inanimate-animate judgment of objects. Participants will be instructed on the four-member sequence and then make judgments on the stimuli based on the sequence. Their reaction time and memory will be evaluated in the sequence transitions and within the sequence to see if they differ. Understanding how task sequence execution and event segmentation interacts with memory can tell us more about how humans divide the world into meaningful event or manage complicated demands of daily life. This study will expand previous literature by giving insight on the enhancement and impairment of memory encoding in event segmentation. Further studies are needed in order to categorize memory throughout different time points in event segmentation and processing.
Mentor: Elizabeth Chrastil (UC-Irvine)
Project: Processing Goal Directed Navigation
Description of Project: Spatial navigation and awareness play an important aspect in memory, learning, attention, and decision making. It is already known that novel environments pose a challenge for subject exploration; however, the characterization of spatial navigation behaviors depending on instructions about the start and target has not yet been explored. We used virtual reality environments and behavioral analysis tools to explore the role of path direction order in human spatial perception and navigation (ages 25-35). Statistical evidence showed that path direction order had a significant effect in behavioral accuracy between the two conditions. Participants were able to complete a significantly greater number of trials when imparted the standard version of the instructions. However, the subjects’ general performance, such as path efficiency, during these correct trials remained statistically unaffected. Our findings suggest that instruction rearrangement could take place in the brain to process and execute these tasks