Defining Smoothness in Reaching using DeepLabCut with an Ataxic Mouse Model
Location
Suwanee, GA
Start Date
7-5-2024 1:00 PM
End Date
7-5-2024 4:00 PM
Description
As a fundamental component of motor function, the cerebellum coordinates movement via the cerebello-thalamo-cerebral pathway. Spinocerebellar ataxia is a progressive neurodegenerative disease inherited in an autosomal dominant manner. Clinical manifestations of Spinocerebellar ataxia include dysmetria, dysdiadochokinesia, abnormal gait, and visuomotor deficits. Dysmetria is characterized by the inability to coordinate precise, smooth movements, especially in reaching. In this study, mice were trained to perform a reaching task in order to study dysmetria. Recorded movements were analyzed using markerless pose-estimation and tracking software, DeepLabCut (DLC). All animal procedures were in accordance with the protocol approved by the IACUC of PCOM. For experimentation, a reaching-pod incorporating a head-fixed mount stabilizes the mouse. A needle is positioned 0.5 mm - 1.0 mm from the nose to deliver a single water drop. Normal C57BL6/J mice, and B6(Cg)-Atxn3/J transgenic ataxic type III mice (Jackson laboratory) were used in this study. It is hypothesized that normal mice exhibit smoother reaching behavior than ataxic mice. To elicit reaching behavior, mice were placed under water restriction and kept above 80% baseline weight. Training occurs over a period of 7 days and each mouse practices to reach for water administered by a needle through a slit in a box. As learning improves, mice are introduced and accustomed to the reaching-pod. Using a Baslar 1920-A camera, reaching behavior is recorded and processed in a Pylon Interface at 100 frames per second. The pCLAMP paradigm has a length of 11 seconds for recording. Pulses are delivered every 10 ms to the camera to synchronize the video recording. The final recording for each trial is 10 seconds in duration. After DLC training and tracking analysis, the output data containing tracked coordinates of the front paw is imported into Matlab. The moving path was reconstructed in 3D. Smoothness was measured by calculating the velocity changes and deviation from a straight line (smoothness_index = (abs(sum(accelerations)) * abs(sum(diff(velocities)))) / (absolute_deviation_mm * total_time_seconds)). Preliminary data was used to test this equation and this is an effective way to measure smoothness between normal and ataxic mice. This equation will be improved based on more data collected from future experiments in order to test our hypothesis.
Embargo Period
5-23-2024
Defining Smoothness in Reaching using DeepLabCut with an Ataxic Mouse Model
Suwanee, GA
As a fundamental component of motor function, the cerebellum coordinates movement via the cerebello-thalamo-cerebral pathway. Spinocerebellar ataxia is a progressive neurodegenerative disease inherited in an autosomal dominant manner. Clinical manifestations of Spinocerebellar ataxia include dysmetria, dysdiadochokinesia, abnormal gait, and visuomotor deficits. Dysmetria is characterized by the inability to coordinate precise, smooth movements, especially in reaching. In this study, mice were trained to perform a reaching task in order to study dysmetria. Recorded movements were analyzed using markerless pose-estimation and tracking software, DeepLabCut (DLC). All animal procedures were in accordance with the protocol approved by the IACUC of PCOM. For experimentation, a reaching-pod incorporating a head-fixed mount stabilizes the mouse. A needle is positioned 0.5 mm - 1.0 mm from the nose to deliver a single water drop. Normal C57BL6/J mice, and B6(Cg)-Atxn3/J transgenic ataxic type III mice (Jackson laboratory) were used in this study. It is hypothesized that normal mice exhibit smoother reaching behavior than ataxic mice. To elicit reaching behavior, mice were placed under water restriction and kept above 80% baseline weight. Training occurs over a period of 7 days and each mouse practices to reach for water administered by a needle through a slit in a box. As learning improves, mice are introduced and accustomed to the reaching-pod. Using a Baslar 1920-A camera, reaching behavior is recorded and processed in a Pylon Interface at 100 frames per second. The pCLAMP paradigm has a length of 11 seconds for recording. Pulses are delivered every 10 ms to the camera to synchronize the video recording. The final recording for each trial is 10 seconds in duration. After DLC training and tracking analysis, the output data containing tracked coordinates of the front paw is imported into Matlab. The moving path was reconstructed in 3D. Smoothness was measured by calculating the velocity changes and deviation from a straight line (smoothness_index = (abs(sum(accelerations)) * abs(sum(diff(velocities)))) / (absolute_deviation_mm * total_time_seconds)). Preliminary data was used to test this equation and this is an effective way to measure smoothness between normal and ataxic mice. This equation will be improved based on more data collected from future experiments in order to test our hypothesis.