Biology subjects

Choi, W. S.

Publications and source records attributed to Choi, W. S..

2 recordsLinked to original sources

bioRxiv2020

Impaired hand dexterity function in a non-human primate model with chronic Parkinson's disease

Symptoms of Parkinsons disease (PD) caused by loss of dopaminergic neurons are accompanied by movement disorders, including tremors, rigidity, bradykinesia, and akinesia. Non-human primate (NHP) models with PD play an essential role in the analysis of PD pathophysiology and behavior symptoms. As impairments of hand dexterity function can affect activities of daily living in patients with PD, research on hand dexterity function in NHP models with chronic PD is essential. Traditional rating scales previously used in the evaluation of animal spontaneous behavior were insufficient due to factors related to subjectivity and passivity. Thus, experimentally designed applications for an appropriate apparatus are necessary. In this study, we aimed to longitudinally assess hand dexterity function using hand dexterity task (HDT) in NHP-PD models. To validate this assessment, we analyzed an alteration in Parkinsonian tremor symptoms, loss of dopaminergic neuron, and positron emission tomography (PET) imaging of dopamine transporters (DAT) in these models. HDT latency significantly increased in NHP-PD models. In addition, a significant inverse correlation between HDT and DAT was identified, but no local bias was found. The correlation with intention tremor symptoms was lower than the resting tremor. In conclusion, the evaluation of HDT may reflect behavioral symptoms of NHP-PD models. Furthermore, HDT was effectively used to experimentally distinguish intention tremors from other tremors.

neuroscience↗

bioRxiv2020

Gait analysis of healthy rhesus monkeys using a pressure-sensing walkway system

Gait analysis in non-human primate models has been performed to elucidate the neural systems involved in controlling quadrupedal locomotor behavior. This study aimed to use a pressure-sensing walkway to identify characteristics of species-specific quadrupedal locomotion in rhesus monkeys. A total of nine healthy adult female rhesus monkeys (Macaca mulatta) were used for gait analysis. We measured the temporo-spatial and kinetic parameters of quadrupedal gait using a custom-built pressure-sensing walkway and compared the left- and right-side parameters to assess the symmetry of the gait pattern. All temporo-spatial and kinetic parameter values showed no significant differences among the nine rhesus monkeys for both the forelimbs and hindlimbs. However, significant differences were observed between forelimb and hindlimb kinetic parameters such as peak vertical force, vertical impulse, and the percentage of body weight distribution. All kinetic parameter values were higher for the forelimbs than for the hindlimbs. These data indicated that the center of gravity in healthy rhesus monkeys is located at the forelimbs rather than at the hindlimbs while walking. Furthermore, the symmetry indices considered for symmetric gait pattern showed a low variability. Most median symmetry index values were nearly zero, indicating no difference between the right and left sides. This study described valid methods for assessing gait parameters and demonstrated rhesus-specific characteristics of quadrupedal locomotion, providing a basis for the assessment of gait normality in rhesus monkeys.

animal behavior and cognition↗