20 April 2017
A preprint in bioRxiv last month – A fully automated computer based Skinner box for testing learning and memory in zebrafish – describes detailed protocols for two automated tests of learning and memory in adult zebrafish using the Zantiks AD unit. This work, conducted by Alistair Brock out of Caroline Brennan’s lab, was designed along the lines of a rodent operant box and demonstrates comparable representative results from a Pavlovian fear conditioning task and a 5-choice serial reaction time task (5-CSRTT).
Fear conditioning is widely used to assess the neurobiology learning and memory. In the Pavlovian fear conditioning assay, Brock et al, conditioned fish to avoid a colour stimulus (conditioned stimulus, CS) associated with a brief, mild electric shock. During the baseline phase, fish showed no preference for either of the stimuli. Following conditioning fish avoided the CS, spending only 10% of the test time in its vicinity, demonstrating that zebrafish learn to actively avoid a CS following only one session of training.
The 5-CSRTT is a standard task for measuring attention and impulse control in rodents and is useful in studying neuropsychiatric disorders, such as ADHD and schizophrenia. Fish trained to perform in the 5-CSRTT exceeded learning criterion (70% accuracy) within 20 days. By the final day of training, omissions (no response following stimulus presentation) had fallen to just 14%. By using Zantiks’s fully automated and scalable system, these results exceed the proportion of correct responses found in previous research (~80% here vs ~60% previously).
As the number of zebrafish publications increase, the need for standard, robust methodologies and repeatable results is increasing. Automated testing of zebrafish cognition and behaviour is advantageous as it saves both time and money, and allows for reliability and standardisation between and within labs. Using the Zantiks AD unit, researchers demonstrated two fast and robust protocols with applications in modelling psychiatric and neurodegenerative diseases and characterisation of complex cognitive phenotypes.
Read the full paper online at biorxiv.