@article {LucianiENEURO.0488-19.2020, author = {Karling R. Luciani and Jude A. Frie and Jibran Y. Khokhar}, title = {An Open Source Automated Bar Test for Measuring Catalepsy in Rats}, elocation-id = {ENEURO.0488-19.2020}, year = {2020}, doi = {10.1523/ENEURO.0488-19.2020}, publisher = {Society for Neuroscience}, abstract = {Catalepsy bar tests are widely used to measure the failure to correct an imposed posture resulting from muscular rigidity. Procedures for measuring catalepsy vary greatly in the published literature, but one commonly used test measures the time it takes for a rodent to remove one or both of its forelimbs from a bar. The following paper describes an affordable, adjustable, open-source bar test that automatically measures and logs the time it takes for a rat to remove itself from a bar. While commercially available automated bar tests are prohibitively expensive, requiring proprietary software and hardware to operate, the proposed apparatus runs on an Arduino-based microcontroller making it low-cost and customizable. This 3D-printed design costs less than $65 USD to build and is simple to assemble and operate. The beam-break sensor design also eliminates many of the pitfalls of the {\textquotedblleft}complete-the-circuit{\textquotedblright} based approach to recording catalepsy. The paper further describes the successful validation of the design using adult male rats injected with different doses of haloperidol to demonstrate a dose-dependent cataleptic effect. This design provides a versatile, low-cost solution to standardizing and automating measurement of catalepsy in rodents.Significance statement: Catalepsy measurements are important in behavioral research involving antipsychotic drugs, Parkinson{\textquoteright}s disease, schizophrenia, and cannabis exposure. Standardized ways of measuring catalepsy will lead to more accurate data, while allowing for consistency between studies. To this end, we designed and constructed a catalepsy bar test that automatically measures and records the time it takes for a rat to remove its forelimbs from a bar. This easy-to-build apparatus will allow for unbiased, human-error free measurements to be made at a very low cost.}, URL = {https://www.eneuro.org/content/early/2020/03/13/ENEURO.0488-19.2020}, eprint = {https://www.eneuro.org/content/early/2020/03/13/ENEURO.0488-19.2020.full.pdf}, journal = {eNeuro} }