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 a beam break that is attached directly above the bar. The bar can be moved vertically to adjust the height appropriate for the animal’s size. Upon breaking the beam, the timer begins to count in 0.1 second increments. When the beam realigns, the timer freezes; it cannot be re-broken for a period of 5 seconds to ensure the beam doesn't reset while the rat is removed.