Excitability change of the Purkinje cells after tetanus stimulation in the molecular layer of the rat cerebellum
Location
Georgia
Start Date
12-5-2015 1:00 PM
Description
Traditionally, the function of the cerebellum has been thought to be associated with motor control or motor learning. Early studies have shown that cerebellar plasticity plays an important role in cerebellar motor learning. However, a recent study using mutant mice lacking parallel fiber-Purkinje cell long-term depression (LTD) suggested that this specific LTD is not fundamental for motor learning. Therefore, cerebellar plasticity including LTD may have other functions in the cerebellum. We hypothesize that cerebellar plasticity modifies the excitability of Purkinje cell to maintain the homeostasis. To test the hypothesis, whole-cell patch clamp recordings were performed on Purkinje cells using neonatal rat cerebellar slices. Tetanus stimulation (1 Hz of train stimulation: 50 Hz, 20 ms interstimulus interval) was delivered to the parallel fibers in the molecular layer. From 20 Purkinje cells that were recorded, 4 cells displayed LTD, 4 demonstrated long-term potentiation (LTP), and 12 cells showed no plastic changes. The excitability of the Purkinje cells was measured by number of action potentials generated using positive current injections (0.1, 0.3 and 0.5 nA, 500 ms). In general, the results demonstrated that the excitability decreased after the tetanus stimulation, but there was no significant difference statistically. Further studies with an improved method of testing the cell excitability is needed.
Excitability change of the Purkinje cells after tetanus stimulation in the molecular layer of the rat cerebellum
Georgia
Traditionally, the function of the cerebellum has been thought to be associated with motor control or motor learning. Early studies have shown that cerebellar plasticity plays an important role in cerebellar motor learning. However, a recent study using mutant mice lacking parallel fiber-Purkinje cell long-term depression (LTD) suggested that this specific LTD is not fundamental for motor learning. Therefore, cerebellar plasticity including LTD may have other functions in the cerebellum. We hypothesize that cerebellar plasticity modifies the excitability of Purkinje cell to maintain the homeostasis. To test the hypothesis, whole-cell patch clamp recordings were performed on Purkinje cells using neonatal rat cerebellar slices. Tetanus stimulation (1 Hz of train stimulation: 50 Hz, 20 ms interstimulus interval) was delivered to the parallel fibers in the molecular layer. From 20 Purkinje cells that were recorded, 4 cells displayed LTD, 4 demonstrated long-term potentiation (LTP), and 12 cells showed no plastic changes. The excitability of the Purkinje cells was measured by number of action potentials generated using positive current injections (0.1, 0.3 and 0.5 nA, 500 ms). In general, the results demonstrated that the excitability decreased after the tetanus stimulation, but there was no significant difference statistically. Further studies with an improved method of testing the cell excitability is needed.