The ability to track moving objects with our eyes is a fundamental aspect of visual perception. This experiment investigates the time course of eye movement responses to different types of motion stimuli, distinguishing between simple reflex tracking and choice-based tracking. The MePMoS theory predicts that simple reactions to stimuli will occur within one theta cycle, while choice-based reactions to stimuli will occur within two theta cycles. From this, we hypothesized that reflexive reactions will occur within approximately 200 ms (one theta cycle), while choice-based reactions occur in approximately 400 ms (two theta cycles). In both simple and complex reaction protocols participants were asked to track a gray ball moving horizontally across a computer screen. After 1-2 seconds, the ball would split into two balls, one moving up and the other moving down. In the simple protocol, both split balls remained gray and participants were told to follow either ball. In the complex protocol after the split, one ball was red and one was blue (one moving up one moving down, randomly switching each trial) and participants were told to follow the red ball. The eye tracking data was collected using VR headsets. Our results indicated that choice-based tracking took approximately 2 theta cycles while simple (reflective) tracking took 1 theta cycle. Our results supported our hypothesis and the MePMoS theory.

Color perception is very fundamental to human vision, but our understanding of its function at a cortical level is not completely understood. In previous studies of Gabor patterns, a striped pattern modeled after a sinusoidal wave, it was found that the brain perceives this pattern through neural activation of the visual cortex V4, particularly through gamma oscillations of high frequency (40-50Hz). Due to recent findings that the visual cortex V4 converts the hue, saturation, and lightness of color into a local two-dimensional map, we hypothesize that the perception of color is similar to that of Gabor patterns in that gamma waves are critical to its perception. This 2D map of V4 implies a spatial difference between colors of differing hues, which we hypothesize leads to phase differences between gamma waves as they propagate across the cortical surface, creating short but measurable time delays, thus leading to a difference in perception. We tested this hypothesis by measuring the reaction time of participants when reacting to different colors (red, green, blue, yellow), finding a difference in reaction time similar to that of a phase difference of gamma waves, roughly 10-20 milliseconds. These findings support our hypothesis that the phase difference of gamma waves in visual cortex V4 is critical to the human perception of color and highlights a temporal element in color perception that has not been widely studied.

Norepinephrine (NE) plays a critical role in regulating drug addiction and reward. Studies using conditioned place preference (CPP) testing with mice have shown that NE in the nucleus tractus solitarius (NST) is particularly necessary for morphine drug reward. The mu opioid receptor (MOR) system is also a key modulator of opioid drug reward. MOR is abundant in noradrenergic cells, though their functional relationship remains unclear. We hypothesized that MORs in NE cells are essential for morphine drug reward. This was tested using a transgenic mouse line that selectively knocked out MOR from NE neurons. CPP testing using a 3-chamber, counterbalanced design was performed on 8 Cre+ knockout mice and 8 Cre- wild-type mice. The experimental timeline involved three days of handling and conditioning to the apparatus, followed by six days of conditioning. During conditioning, mice received morphine (10 mg/kg, i.p.) or saline on alternating days and were conditioned to associated boxes. Time spent in the drug-paired side was measured during a context-dependent test (no drug) and a state-dependent test (morphine administered). Cre+ mice showed a significant increase in time spent in the drug-paired chamber compared to Cre- mice, primarily driven by females. Knockout of MOR from NE cells was confirmed in the locus coeruleus and NST using in-situ hybridization and immunohistochemistry. Contrary to the hypothesis, morphine reward was increased in mice lacking MOR in NE neurons, suggesting a more complex interplay.

The SSPsyGene initiative, launched by NIMH, aims to characterize 100 high confidence genes associated with neurodevelopmental and psychiatric disorders (NPD) such as autism and schizophrenia. To date, our team has successfully generated a repository of 700 clonal homozygous knockout induced pluripotent stem cell (iPSC) lines using CRISPR/Cas9 technology in both a male and female background.Our efforts now focus on the high throughput characterization of these lines in cell types relevant to NPD including neural progenitor cells and cortical neurons. Here we describe a systematic approach to assessing pluripotency, marker expression, and morphology in these model systems. To analyze these properties in high throughput , we developed a semi-automated pipeline that captures neuronal projections, synapses, and cell marker expression. This Python-based pipeline utilizes various open-source computational tools for cell segmentation, mask generation, and phenotype quantification. With such information, we can form quality control procedures and collect essential data for our experiments.

Slow oscillations (SO) in electroencephalograms (EEG) recordings are a characteristic of non-rapid eye movement (NREM) sleep. This coordinated activity in neural populations—alternating between up-states (intense firing) and down-states (silence)—is crucial for memory consolidation and synaptic plasticity. Disruptions of SOs are observed in Alzheimer's disease and aging. Delta waves (DW) are high amplitude slow oscillations (0.5–4 Hz) that are distinct from SOs, but have strong associations with SO down-states during non-REM sleep. In the Paul Lab, EEG sleep recordings are scored and classified into NREM, REM, and awake states, and DWs are analyzed using fast Fourier transform (FFT). However, these analyses do not have the capacity to gather information about SOs. I refined an approach to extract SO information from measurable DW data using the groundwork of a MATLAB script developed in the Paul Lab. I improved the documentation of the data processing steps and introduced a step to allow compatibility with data formats from newer software, ensuring the long-term usability and adaptability of the script. This work expands the types of analyses performed on EEG files, leveraging existing data to provide insights into memory, plasticity, and restorative processes during sleep. Preliminary data from a cohort of recombinant inbred BXD mice reveal a time-dependent component of SOs that is independent of DWs. This finding suggests that SOs may provide insights about the relationships between sleep and synaptic plasticity.