5 minute read
Session A Neuroengineering 1
Track 1
Session A
Advertisement
Neuroengineering 1
26 BME SENIOR DESIGN PROJECTS
40 Hz Light Enhancement Study
Team 19: Noah Abrha, Anton Homenuik, Eden Gideon, Jed Lartey, Medua Nwokolo Technical Advisor: Andrey Vyshedskiy (ImagiRation, LLC & BU MET)
Cognitive impairment affects over 16 million people in the US. The current gold standards of treatment for most cognition impairing conditions are prescribed psychostimulants. These medications come with multiple side effects and leave room for misuse leading to addiction and pose other health risks. An alternative non-intrusive, safe, and accessible method of improving cognitive performance can contribute to solving this problem. The brain produces electrical activities, known as gamma waves, which are essential for processing and connecting information. Light delivered at 40 flashes per second has been shown to restart the natural 40Hz gamma rhythm of the brain. These gamma waves are associated with memory and cognition, which are affected as a result of cognitive impairments. We ran a study using 40 Hz light stimuli administered through an iPad pro. The participants consisted of a group of college students with conditions affecting their cognition or in a state of fatigue to closely resemble individuals with cognitive disabilities. Subjects were made to take a 10 question arithmetic long addition test with 40 Hz light constantly on or off to determine the effect of light on their performance. Our findings showed a jump in performance from the first trial to the second when light was administered. However, this was attributed to the effect of practice and not a consequence of the 40 Hz light. Although, there has been an overall trend of improvement across subjects, the results thus far show no statistical significance in the effect of 40 Hz light on cognition.
Development of Behavioral Task to Study Motor Control in Mice
Team 20: Antoine Baize, Rachel Ferrigno, Sydney Holder, Zenia Valdiviezo Technical Advisors: Michael Economo, Munib Hasnain
The motor cortex of the brain has been shown to exhibit preparatory, or planning, activity before the execution of a movement. However, much is still unknown about the selective activation of regions of the brain corresponding to motor planning and motor execution. Current motor control studies that observe preparatory signals in the anterolateral motor cortex (ALM) in mice are constrained by a two-directional task paradigm (2AFC) in which a mouse licks one of two lick-sites for a water reward. Implementing a delay period in a 2AFC task allows for the isolation of the preparation and execution activity signals associated with distinct movements. We aimed to expand this paradigm by designing a new task in which mice will be trained to plan three directional movements (rightlick, left-lick, or center-lick) based on unique instructional tones and an enforced delay period. Central to our task was the design of a “lickport” to house the three straws that the mouse licks as the motor task. We tested the feasibility of each lickport design by determining whether the mouse could lick each site individually (i.e. they were not too close or too far apart). We also explored the selection and placement of speakers and LEDs as auditory and visual cues within our task. In the future, the mice trained to perform this task will exhibit an increased number of unique directional licking movements in the experiment. This will allow more complex neural activity patterns to be studied and may eventually expose more spatial and temporal correlations between movement preparation and execution signals.
Team 23: Allan Garcia, Stefan Lütschg Technical Advisors: Laura Lewis, Joshua Levitt
Simultaneous Electroencephalography & Functional Magnetic Resonance Imaging, (EEG-fMRI), is a brain imaging technique that combines the high spatial resolution of fMRI with the high temporal resolution of EEG. However, the usage of magnets in fMRI induces electrical currents which are also picked up by the EEG scalp electrodes, this is an effect of Faraday’s Law which creates electrical noise. Inside the magnetic field the cardiovascular system of the human skull also creates artifacts known as Ballistocardiogram (BCG) noise and this reduces the clarity of EEG data. Researchers try to remove these artifacts by designing and producing reference layers which consist of insulating and conductive pieces of fabric that collect BCG noise, allowing for the reduction of artifacts in post-hoc analysis. These Reference Layers tend to be crudely made to fit researchers’ specific needs. In the Lewis Lab, we’ve created a standardized design for a double-sided Reference Cap, consisting of a single fabric that has holes cut out for EEG Scalp Electrodes. This fabric has an insulating spandex side that makes contact with the scalp and a nylon fabric side that makes contact with EEG Reference Electrodes. This nylon fabric is coated in poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), an electrically conductive polymer that is safe for usage in MRI machines. With this design, we are able to provide a design that is easy to replicate and assemble in any lab. This design functions well as a reference layer, allowing researchers to attenuate noise found during EEG-fMRI imaging.
Computer Automated Neuron Identification in Functional Microscopy for C. elegans
Team 34: Jun Young Choi, Laura Mazuera Technical Advisors: Andrew Chang (BU School of Medicine), Christopher Connor (BWH & BU School of
Medicine), Christopher Gabel (BU School of Medicine)
Current neuroimaging techniques are capable of capturing real-time neuronal activities, indicating areas of neuronal stimulation. However, state-of-art microscopes have compromised resolution, capturing the average neuronal activities of thousands of neurons in a single voxel. Due to this resolution limitation, the activities and interactions between individual neurons can only be inferred. To overcome the limitation, we have chosen hermaphrodite C. elegans with GCaMP and NeuroPAL transgene as our specimen. Hermaphrodite C. elegans’ neuronal system consists of stereotyped 302 neurons. The GCaMP transgene allows for fluorescence in response to calcium levels, which serves as a proxy of neuronal activity. Calcium levels alone are insufficient to map individual neuronal activity because each neuron is susceptible to positional changes. To accurately locate individual neurons, neuroPAL transgene is implemented. NeuroPAL transgene is designed to characterize neurons with a unique fluorescence color, providing a means to differentiate neurons by its fluorescence coupled with approximate location. To accurately capture the positional and fluorescence data, images are acquired with Dual Inverted Selective Plane Illumination Microscope (DiSPIM). DiSPIM microscope has isotropic resolution, compared to the conventional confocal microscope which has compromised z-direction resolution. The acquired images are then processed with an automatic neuron labeling algorithm that labels each neuron with the be both position and color. Altogether, this algorithm allows tracing neuronal activity of individual neurons in real-time, which can be utilized to examine the effect of various stimuli on neuronal activity and interactions in a single neuron resolution.
