ALTERATION OF FREQUENCY RELATED PATTERNS OF CANNABINOID RECEPTORS ON CEREBELLAR PURKINJE CELLS UNDER WHOLE CELL PATCH CLAMP RECORDING FROM HARMALINE-INDUCED TREMOR RATS

Background and Aim : Essential tremor (ET) is the most common neurological motor-related disorder leading to impairment in daily living activities. Despite great number of cannabinoid receptors in cerebellum and basal ganglia, areas mainly responsible for motor function, and the reports of tremor benefits among ET patients using cannabis, still not many research studies have been conducted in this issue. In this paper, the effects of WIN 55,212-2 (WIN) as an agonist and AM251 and Rimonobant as antagonists on tremor-induced rats were studied at the level of cellular recording. Methods : 4-week-old rats were randomly divided into 5 groups; 2 normal saline and harmaline-injected controls along with 3 WIN, AM251 and Rimonobant-treated groups. Cerebellar purkinje cells were under electrophysiological examinations using whole cell patch clamp recording and different aspects of their activities were evaluated; action potential frequency, peak amplitude, action potential half width, time to peak, after hyperpolarization (AHP) and instantaneous frequency were measured by digidata 1440 and pclamp10.1 software offline and analyzed by prism 6.Results : The results showed a significant increase in action potential frequency and instantaneous frequency in the group treated with WIN (1mg/kg) compared to tremor-induced group. Peak amplitude was attenuated and AHP was decreased in WIN-treated rats. Further, time to peak and action potential half width were reduced by WIN, while AM251 did not show significant difference in these two above-mentioned factors comparing with harmaline-injected rats. Conclusion : Thus, application of WIN did not represent any association with normal control pattern while cannabinoids antagonists tracked the standards to such an extent. Since cannabinoids effects are grabbing loads of attention in CNS-related motor discomforts and as concluded, cannabinoid receptor antagonists appeared to be more eligible in treating tremor-induced rats, they are considered as potential candidates for tremor management.

کلیدواژه ها:

Whole Cell Recording ، Harmaline ، Tremor ، Cannabinoid