A Go/No-go delayed nonmatching-to-sample procedure to measure object-recognition memory in rats

Area of Science:

• Neuroscience
• Animal Behavior

Background:

• The novel-object preference (NOP) test is a common method for assessing object-recognition memory in rats.
• Concerns exist regarding the internal validity of the NOP test for accurately measuring memory persistence or accuracy.

Purpose of the Study:

• To develop and validate a new Go/No-go delayed nonmatching-to-sample (DNMS) procedure for assessing object-recognition memory in rats.
• To address the interpretational limitations of the NOP test.

Main Methods:

• Rats were trained on a Go/No-go DNMS task where they learned to displace novel objects for rewards and avoid displacing familiar ones.
• Performance criterion was set at 80% correct choices over five consecutive sessions.
• Following DNMS training, rats were tested on the NOP test.

Main Results:

• The Go/No-go DNMS task required an average of 54 sessions to reach the performance criterion.
• Performance on the Go/No-go DNMS task was not significantly correlated with novelty preference scores on the NOP test.
• This indicates that the DNMS task performance does not predict NOP test scores.

Conclusions:

• The Go/No-go DNMS procedure offers a valid alternative for assessing object-recognition memory in rats.
• This new method circumvents the interpretational issues associated with the NOP test.
• The findings highlight the benefits of alternative approaches for robust memory assessment in animal models.