Catalepsy is a state of behavioural immobility characterized by muscular rigidity and failure to correct an imposed posture for a prolonged period of time. Measuring catalepsy is of interest to our lab due to its similarity to behaviours seen in human disorders such as schizophrenia and Parkinson’s disease. This test is also used as a part of the tetrad for the pharmacological effects of cannabinoids, as well some of the extrapyramidal side effects of antipsychotic drugs.
The test apparatus includes an automated timer connected to beam-break sensors which are attached directly above the bar. The bar can be moved vertically to adjust the height appropriate for the animal’s size. The timer starts once the rat’s forepaws are resting on the bar. When the rat descends from this posture, the break-beam sensors cause the timer to stop and the time is shown on an LCD display. The data is logged to a .csv file on an SD card. A push button saves the elapsed time into the logging module. The addition of data logging allows the researcher more potential for performing the behavioural measure without additional help.