Impaired Hand Dexterity Function in a Non-human Primate Model with Chronic Parkinson’s Disease

Abstract

Symptoms of Parkinson' s 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 the alteration in Parkinsonian tremor signs and the functionality of presynaptic dopaminergic neuron using positron emission tomography imaging of dopamine transporters in these models. In addition, a significant inverse correlation between HDT and DAT level was identified, but no local bias was found. The correlation with intention tremor signs 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.

Determination of the Unilaterally Damaged Region May Depend on the Asymmetry of Carotid Blood Flow Velocity in Hemiparkinsonian Monkey: A Pilot Study

“…The interventional radiology method employed in this study was performed as reported in our previous studies [ 17 , 30 – 33 ]. All monkeys were anesthetized with ketamine (5 mg/kg, I. M, Yuhan, Seoul, South Korea) and maintained with isoflurane (2%, Hana Pharmacy, Hwaseong, South Korea).…”

“…All MRI examinations were conducted using a Philips 3T Achieva scanner (Philips Medical System, Best, Netherlands) with a 32-channel head coil. Monkeys were comfortably restricted in a supine position in a custom-made bed holder during MRI scans [ 17 , 32 , 33 ]. Inhaled CO 2 , O 2 saturation, pulse, respiration rate, and body temperature were continuously monitored.…”

“…PET imaging was carried out to measure the DAT activity using a PET/computed tomography (CT) scanner (nanoScan PET-CT, Mediso Ltd., Budapest, Hungary), as reported in our previous studies [ 17 , 26 , 33 , 41 ]. The 18 F-FP-CIT was acquired from DuChemBio Co., Ltd., Daejeon, Korea.…”

“…185 MBq 18 F-FP-CIT in 1.5 mL saline were administrated via the saphenous vein after CT was conducted for attenuation correction. The PET imaging analysis was performed according to the protocol reported in previous studies [ 17 , 33 ].…”

“…Behaviors were recorded consecutively for 240 min (12 : 00–4:00 p.m.), and the global activity of three monkeys was evaluated via analysis of the video recordings using Smart 3.0 software (Panlab S. L., Barcelona, Spain), as previously reported [ 17 , 26 ]. Based on the Kurlan scale, Parkinsonian behavior scores were evaluated in the monkey PD model [ 17 , 26 , 33 , 42 , 43 ]. The minimum degree is 0 (indicating a normal behavior movement), whereas the maximum degree is 29 (indicating severe Parkinsonian motor symptoms).…”