Spatial skills are crucial for understanding and navigating the physical world around us. Previous research indicates spatial development begins in infancy, with sex differences present early on. These skills are predictors of later STEM achievement, highlighting the importance of nurturing them from a young age. Our study explores the impact of spatial language and play style on infants’ spatial development. We replicated a change detection mental rotation task for infants using an eye-tracker (N = 115, 47 girls, M age = 11.21 months). As infants preferentially look at novel stimuli, we recorded looking time as a measure of recognition of a change in stimulus. Additionally, we observed parent-infant dyads during play, and parents completed a survey on their infant's play, language, and motor skills. We hypothesized that parents would use more spatial language during spatial play than non-spatial play. We were also interested in whether play and language use varied by child sex. Infants showed no preference for the novel stimulus in the mental rotation task, suggesting it might not effectively measure mental rotation in infancy. Parent-infant dyads varied in engagement with the spatial toy, and no significant sex differences emerged from these measures. Due to the null findings in our change detection task, we will be designing and testing a new task for measuring mental rotation ability in infancy. Furthermore, we will also conduct analyses on the relationship between individual differences in spatial language and play to explore how these factors impact the development of spatial abilities. These findings provide insights to better support spatial development in early life.

The peptide neurotensin (NTS) has been known as a regulator of dopamine neuron activity and its system, which modulates numerous functions in the brain. Although ample research has now demonstrated that NTS in Ventral Tegmental Area (VTA) increases dopamine release in some regions, much remains unknown about the endogenous sources of NTS in the VTA and the impact of physiological NTS release. Recent NTS mapping data from the Soden lab demonstrated that there is a NTS projection from Periaqueductal Gray (PAG) to the VTA and also to hindbrain regions including the ventral medulla. This project investigates the effect of this interconnection between these three regions on the dopamine system. Utilizing advanced techniques in circuit mapping, mice will be injected in the VTA and the ventral medulla with fluorescent Retrobeads or a retrograde virus (rAAV2 anti mcherry or GFP), which are taken up by synaptic terminals and migrate up the axon retrogradely to label cell bodies, one color assigned for each region. Following euthanasia, mice brains will undergo immunohistochemistry such as histology and in-situ RNA staining. Then, data will be collected using imaging microscopes for results and further analysis. If NTS neurons in the PAG have green and red expressions, this will indicate that the same population of neurons send axons to both downstream regions, compared to PAG NTS neurons with only one color, indicating the presence of two separate neuron populations. Experiments on retrograde mapping of NTS inputs will contribute to building onto our current knowledge about VTA-PAG-ventral medulla circuit and effects on dopamine neurons following their interplay. In the end, our goal is to establish a novel understanding of endogenous NTS signaling mechanisms, mediation of complex reward processes, and treatment targets with experimental outcomes, giving rise to the development of therapeutic interventions towards addiction and related psychiatric disorders.

A key neuromodulatory system involved in anxiety disorders is the locus coeruleus noradrenergic system (LC-NE), which projects broadly throughout the central nervous system. The LC is stress responsive and tonic activation of the LC and its projections to the BLA is anxiogenic. Previously, the Bruchas Lab has used two-photon calcium imaging to show that a powerful stressor (predator odor) increased synchronous activity of LC neurons. They also found that mimicking this predator odor evoked activity with optogenetics altered the activity of individual neurons downstream in the BLA in a β-adrenergic receptor (β-AR) dependent manner. Although these data support the LC's involvement in promoting aversion and increasing anxiety-like behavior, the specific neurotransmitter, neuronal cell types, and receptors responsible for these effects remain unidentified. Therefore in hopes of identifying these specific signaling molecules and neuronal cell types and receptors, I first used fiber photometry and a novel biosensor (GRABNE2m) to detect norepinephrine (NE) release in the BLA while mice were exposed to a predator odor. I found that predator odor produced robust increases in NE release in the BLA compared to control odor (n=5, 3 male, 2 female) Further, we found that optogenetic activation of terminals from the LC to the BLA produced very similar levels of NE release compared to what was evoked by predator odor. To determine the cell type and receptor that is sensing this stress-induced NE release, I used a CRISPR/SaCas9 virus, developed in collaboration with Dr. Larry Zweifel’s lab, to knock-down β2-adrenergic receptors (β2-ARs) in glutamatergic BLA neurons to test their causal role in stress-induced anxiety-like behavior. CRISPR knockdown of β2-ARs in the BLA blocked several stress-induced anxiety-like behaviors (n=4, 4 female). By understanding the circuit-based mechanisms of how stress-induced anxiety is regulated, researchers could identify potential targets for therapeutic treatments of anxiety disorders.

More than 53 million adults or 22% of the US suffer from chronic inflammation. Along with being a critical factor in the onset and progression of aging and cell senescence of the central nervous system, inflammation is also a central hallmark of neurodegenerative diseases and brain injury. Modulation of neuroinflammation has the therapeutic potential to decelerate aging processes in the brain. Studies consistently show that cytokines such as Interleukin (IL)-6, Tumor Necrosis factor (TNF)-α, Monocyte Chemoattractant Protein -1 (MCP-1), and their receptors, are upregulated in aged tissues and cells. This study investigated effects of GHK-Cu, a naturally occurring peptide that has regenerative properties, as a potential therapeutic measure to reduce the expression of these proteins. Mouse SIM-A9 microglial cells and N2A neuroblastoma cells were used as a model system, and bacterial endotoxin (Lipopolysaccharide, designated as LPS) was used as a stressor to trigger an inflammatory response. Cell morphology, viability, and cytokine ELISA assays including IL-6, MCP-1, and TNF-α, provided data suggesting that GHK-Cu peptide is a potent factor in enhancing resistance of neuronal and microglial cell lines to LPS-induced stress by reducing the expression of key inflammatory cytokines.Understanding the mechanisms by which GHK-Cu modulates inflammation can pave the way for the development of novel treatments targeting inflammation-associated diseases, aging mechanisms and various forms of dementia.

Cannabidiol (CBD), a non-psychoactive cannabinoid compound found in cannabis, has been reported to attenuate morphine tolerance and can potentially be used as an alternative to opioids in treating chronic pain. Previous work has established connections between morphine tolerance and Reactive Oxygen Species (ROS) production through JNK-mediated Peroxiredoxin 6 (PRDX6) activation. Excess ROS production promotes desensitization of opioid receptors, which in turn leads to opioid tolerance. CBD administration is associated with decreasing pain-related Reactive Oxygen Species (ROS) production, and it was hypothesized that CBD directly interacts with JNK, blocking JNK’s activities. This project aims to investigate the connections between CBD administration and ROS production to determine CBD’s effects on JNK-mediated ROS production. To quantify ROS production through fluorescence imaging, I will transfect wild-type HEK 293 cells with oROS, a genetically encoded sensor, which fluoresces proportionally to ROS production. Coverslips of HEK 293 cells expressing oROS are treated with buffer (control) and CBD before administration of Tumor Necrosis Factor alpha (TNFα), a known activator for JNK released during pain states. After imaging with oROS, I will quantify ROS production and compare this between groups with and without CBD pretreatment to determine CBD’s activity on inhibiting JNK-mediated pro-inflammatory pathways. I predict that relative to the control, cells treated with CBD will have significantly less ROS production. If the results are consistent with this prediction, CBD could be a potentially promising co-treatment with opioids in managing chronic pain as it can potentially attenuate opioids' side effects like tolerance. 

Cannabis use has dramatically increased in response to legalization in the U.S., with U.S. sales jumping 46% from 2019 to 2020. ᐃ9-tetrahydrocannabinol (THC) is the primary psychoactive compound in Cannabis, and it has been shown to modify learning and motivation amongst regular users. Learning and motivation are key central processes primarily organized by the prefrontal cortex (PFC) brain region. I sought to test effects of THC on PFC activity during appetitive Pavlovian conditioning in mice- a behavior in which a subject learns to pair two stimuli together over time. Doing so provided much needed insight into learning and motivation under the effect of THC. THC acts on the endocannabinoid CB1 receptor, a presynaptic signaling protein responsible for modulating neural activity throughout the brain, with robust expression in the PFC. To monitor neural activity during behavioral trials, we implanted optic fibers into the PFC and virally expressed biological sensors. We used VGLUT1-Cre mice with a Cre-dependent GCaMP6f sensor to selectively target pyramidal glutamatergic activity during conditioning. We also utilized machine learning tracking software, SLEAP, to analyze behavior through video recordings. In our conditioning paradigm, animals were presented with a houselight and a sucrose reward, which they consolidated an association between after many trials. The mice experienced 5 days of Pavlovian conditioning, and I injected a moderate i.p. dose of THC (5 mg/kg) to one cohort, while another was given a vehicle before undergoing further trials. Our preliminary results showed that glutamatergic activity correlated with learning and association to the cue over time. We expected and observed that THC decreased the signals across the animals and reduced motivation. We categorized THC-induced behavior using SLEAP, a program tracking the mouse’s body parts to capture real-time movement, and found that locomotion decreased and resting behaviors increased in the THC cohort.