Elsevier

Journal of Neuroscience Methods

Volume 251, 15 August 2015, Pages 138-142
Journal of Neuroscience Methods

Basic Neuroscience
An experimental evaluation of a new designed apparatus (NDA) for the rapid measurement of impaired motor function in rats

https://doi.org/10.1016/j.jneumeth.2015.05.023Get rights and content

Highlights

  • We evaluate a new apparatus for the rapid measurement of impaired motor function in rats.

  • We examine experimentally the capability of the new apparatus for impaired motor function in rats.

  • We compare experimentally the capability of the new apparatus with rotarod for impaired motor function in rats.

  • The new apparatus is more sensitive than rotarod for evaluating of impaired motor system function.

  • The sensitivity of the new apparatus increases by faster rotation speeds.

Abstract

Background

Assessment of the ability of rat to balance by rotarod apparatus (ROTA) is frequently used as a measure of impaired motor system function. Most of these methods have some disadvantages, such as failing to sense motor coordination rather than endurance and as the sensitivity of the method is low, more animals are needed to obtain statistically significant results.

New method

We have designed and tested a new designed apparatus (NDA) to measure motor system function in rats. Our system consists of a glass box containing 4 beams which placed with 1 cm distance between them, two electrical motors for rotating the beams, and a camera to record the movements of the rats. The RPM of the beams is adjustable digitally between 0 and 50 rounds per minute.

Results

We evaluated experimentally the capability of the NDA for the rapid measurement of impaired motor function in rats. Also we demonstrated that the sensitivity of the NDA increases by faster rotation speeds and may be more sensitive than ROTA for evaluating of impaired motor system function.

Comparison with existing methods

Compared to a previous version of this task, our NDA provides a more efficient method to test rodents for studies of motor system function after impaired motor nervous system.

Conclusions

In summary, our NDA will allow high efficient monitoring of rat motor system function and may be more sensitive than ROTA for evaluating of impaired motor system function in rats.

Introduction

The balance and motor coordination maintaining is a complex function in which several portions of nervous system are involved (Agid, 1990, Johansson and Cole, 1992, Zelenin et al., 2010). Assessment of balance and motor coordination can be used to measure the effects of experimental manipulations or other test compounds on rats or mice nervous system (Hamm et al., 1994, Carter et al., 2001, Fujimoto et al., 2004, Schaar et al., 2010). Widely used protocols and three well-established used methods for assessing balance and motor coordination in rats and mice are ROTA test, footprint analysis and beam walking (Goldstein and Davis, 1990, Rozas et al., 1997, Bervar, 2000).

Currently, ROTA is the most prevalent tool utilized extensively to measure and assesses the balance and motor coordination (Jansen and Low, 1996, Luong et al., 2011, Mandillo et al., 2014). Although, there are several studies regarding the utility of ROTA for motor impairment in laboratory applications (Hamm et al., 1994, Boix et al., 2010), the primary disadvantage of this method is that a number of animals with reduced motor coordination will drop at the beginning, while for those that do continue, the assessment will soon start to measure endurance rather than motor coordination per se. Also there are numerous commercial versions of this apparatus on the market, but a few have disadvantages, such as failing to accelerate at an adequate speed to detect motor coordination rather than endurance (Stanley et al., 2005, Deacon, 2013) and as the sensitivity of the procedure specially with constant speed ROTAs is low, more animals are required to obtain statistically significant results (Jones and Roberts, 1968).

In this research we report the development and testing of an inexpensive apparatus to investigate the balance and motor coordination with more accuracy which we think that can overcome the limitations of ROTA. Therefore, we aim to compare NDA and ROTA on a rat model by conducting a series of motor coordination tests after administration of different doses of ETH and see its effects on different rotation speeds and compare the two apparatuses on rats.

Section snippets

Animals

Adult male Wistar rats (200 ± 10 g) were individually housed in cages (50 cm × 26 cm × 25 cm) and kept on a 12 h-light/dark cycle (lights on at 06:00 h). Food and water were accessible ad libitum. The ambient environment was maintained at a constant temperature (22 ± 2 °C) and relative humidity (50–60%). All studies were conducted between 10:00 and 14:00 h. The experimental protocol was approved by the Ethical Review Board of Semnan University of Medical Sciences (Iran) and all of the experimental trials were

Results

In this study, information of the mean fall latencies or hand errors related to VEH or ETH (0.15 and 1.5 g/kg) groups in each rotation speeds (4, 8, 16 or 20 RPM) of the ROTA or the NDA were compared and analyzed. The results did not show noteworthy differences in mean fall latencies or hand errors between VEH and ETH (0.15 g/kg) groups in each rotation speed of 4, 8, 16 or 20 RPM in ROTA tests, but all comparisons in the NDA showed significant differences between VEH and ETH (0.15 g/kg) groups in

Discussion

The results of our experiment indicate that the NDA may consider as an alternative to the ROTA. As expected, faster speed rates of rods or beams led to decrease latencies to fall in ROTA tests and it increased the rate of error movements in the NDA (Fig. 2). As the results show, the mean duration of the staying of rats on the ROTA that received 0.15 g/kg ETH compare to the rats that were injected only VEH do not show significant differences, consistent with prior studies (Bogo et al., 1981,

Conclusion

Taken together, our results indicates that the NDA has more sensitivity compare to the ROTA. So the new apparatus may be able to detect some of the subtle deterioration of motor coordination which is not possible by the ROTA.

Conflict of interest statement

The authors certify that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

This research was founded and supported by a research grant (grant number: 393) from Semnan University of Medical Sciences (Semnan, Iran). Their contribution is gratefully acknowledged. Also we would like to have a special thank to Dr. Amir Hushang Bakhtiary for his advice and Dr. Nasrolah Moradi for proofreading.

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