Understanding the relationship between neuronal activity and cellular morphology is a central challenge in neuroscience. While genetically encoded calcium indicators allow real-time recording of neuronal activity, they do not preserve detailed structural information about labeled cells after imaging. This project addresses this gap by engineering viral constructs that combine calcium imaging with epitope tag–based labeling to enable both functional recording and post-mortem morphological reconstruction. Methods included molecular cloning, PCR, and engineering modified GFP-based constructs and RFP backbones with added epitope tags, along with antibody staining, brain tissue slicing, and fluorescence imaging. We achieved post-mortem reconstruction of neurons in marmoset brain tissue using GCaMP8s-based labeling, demonstrating the feasibility of linking functional imaging with structural analysis. We are currently applying this system to in vivo neuronal activity imaging to further validate this approach. By enabling structural and functional analysis within the same experimental framework, this approach addresses a key limitation in neuroscience, where neuronal activity is often interpreted without morphological context. In addition, it offers a more ethically and practically scalable approach for studying neuronal circuitry in primate models, where traditional high-throughput anatomical methods are limited.

Vascular Dementia (VaD) is a white matter ischemic disease that can lead to robust cognitive deficits. Microglia, the brain’s immune cells, play central roles in driving VaD responses, including through remodeling of the extracellular matrix (ECM), a network of proteins involved in cellular communication and structural support. Our group has shown that foraging-based enrichment drives microglia and ECM remodeling that aligns with cognitive performance in aged mice. The present study tests whether foraging enrichment drives microglia and ECM remodeling in a VaD mouse model. 36 mice were assigned to Control-Sedentary, VaD-Sedentary, or VaD-Foraging groups. VaD mice received an injection of a vasoconstrictor in the cerebral white matter, whereas controls received a vehicle injection. All mice then completed behavioral phenotyping before and after a four-week sedentary or foraging-enrichment period. Brain tissue was sectioned and dopamine neurons, the ECM, and microglia were histochemically stained. The results of behavioral phenotyping showed a specific deficit on a T-maze alternation task. Preliminary results highlight possible decreases in microglia density in VaD mice across the nucleus accumbens, anterior cingulate cortex, and motor cortex. VaD-foraging mice also exhibited increased ECM density in the anterior cingulate cortex of injected hemispheres. These findings provide insight into how VaD impacts brain structure and function and how behavioral enrichment can modulate non-neuronal mechanisms in support of cognition.

Microglia, the resident macrophages in the central nervous system, have been shown to be dysregulated in autism spectrum disorder (ASD). Haploinsufficiency mutations in chromodomain helicase DNA-binding protein 8 (CHD8) are a known genetic risk factor for ASD, and CHD8 is highly expressed in microglia. This study examines the effects of immune activation using lipopolysaccharide (LPS), a bacterial endotoxin, on the morphological responses of human stem cell-derived microglia with and without CHD8 mutations. Microglia were derived from CRISPR-edited human induced pluripotent stem cells (iPSCs), immunohistochemically stained, and imaged with confocal microscopy at 63x. Cell volume & lysosomal content were quantified and extracted from Z-stack tile images using ImageJ and Imaris. Cells were analyzed across multiple genetic backgrounds and LPS treatment conditions. A combination of statistical tests was applied to assess significance. LPS treatment induced significant increases in microglial cell volume, with background-dependent differences observed in CHD8 mutant lines. Contrastingly, lysosomal content remained largely unchanged by LPS treatment across both control and mutant lines. CHD8 haploinsufficiency may influence baseline microglial morphology but may not substantially alter inflammatory stimulation responses. Future work will investigate interactions between neurons and microglia in co-culture models to further interpret CHD8-related neuroimmune mechanisms in ASD.

Drosophila melanogaster larvae represent a powerful model system for investigating neural function, owing to their fully mapped nervous system, genetic tractability, and compatibility with in vivo imaging using genetically encoded calcium indicators (GECIs). However, motion artifacts remain a barrier to in vivo calcium imaging in Drosophila melanogaster larvae. Here, we present a novel multimodal immobilization technique that combines diethyl ether exposure and hydrogel-based mechanical restraint to achieve stable, long-term immobilization of Drosophila larvae suitable for calcium imaging. Using second-instar larvae expressing the pan-neuronal calcium indicator GCaMP8f, we demonstrate that our method enables in vivo fluorescence imaging of brain activity for up to 1 hour post-preparation, with minimal residual motion if any, and often no need for post-hoc motion correction. Our technique demonstrated a significant reduction in overall motion, speed, and jitter ratio when compared to existing techniques which utilize only hydrogel-based mechanical restraint.

Auditory alpha oscillations (8–12Hz), primarily generated in posterior cortical regions, play an important role in sensory gating and attention. Complex sounds engage the posterior temporal cortex (PTC), and prior studies in healthy young adults show that continuous white noise reduces alpha power, reflecting increased arousal and sensory processing. However, effects in aging and cognitively impaired (CI) populations remain unclear. We hypothesized that PTC activity (T5, T6 electrodes) would show alpha modulation during white noise in cognitively normal (CN) older adults, with attenuated responses in CI individuals. EEG data were collected from 7 CN and 6 CI participants using a 10–20 system. Participants completed a 5-minute baseline (silence) and 1-minute white noise condition. Alpha-band power spectral density (PSD) was computed and compared between conditions at T5 and T6. In CN participants, T5 and T6 showed significant reductions in alpha PSD during white noise compared to baseline (p = 0.046). CI participants showed no significant change. The control channel (Fz) showed no effects in either group. These findings support PTC involvement in auditory alpha modulation to spectrally complex sounds and show decreased alpha activity in healthy aging individuals during white noise. The lack of modulation in CI individuals may reflect reduced network responsiveness, consistent with tau-related pathology. Temporal alpha responses to white noise may serve as a marker of temporal lobe network function in aging populations.