Effects of increased spatial complexity on behavioural development and task performance in Lister Hooded rats

Area of Science:

• Laboratory animal science
• Animal welfare research
• Cognitive ethology

Background:

• Environmental enrichment is crucial for laboratory animal welfare, particularly in rodents.
• Traditional enrichment methods impact development, reproduction, and cognition.
• The effects of increased spatial complexity in novel caging systems on animal development and performance are under-investigated.

Purpose of the Study:

• To investigate the effects of housing in spatially enriched cages versus traditional cages on rat behavior and cognitive performance.
• To compare maternal behavior, offspring development, and task performance in female rats under different housing conditions.

Main Methods:

• Lister Hooded rats were housed in either traditional single-shelf cages ('basic') or larger cages with an additional shelf ('enriched').
• Maternal behavior and offspring development were monitored.
• Cognitive performance was assessed using a hippocampus-dependent T-maze task and a hippocampus-independent Novel Object Recognition (NOR) task in female rats.

Main Results:

• Minor differences were observed in maternal behavior and offspring development between the housing groups.
• No significant differences were found in learning rate or probe trial performance in the T-maze task.
• Female rats in enriched cages demonstrated superior performance in the Novel Object Recognition (NOR) task compared to those in basic cages.

Conclusions:

• Increased spatial complexity in caging systems does not significantly affect rodent development or maternal performance.
• Spatially enriched housing may enhance non-spatial learning abilities in female rats.
• The effects of spatially enriched caging differ from those of traditional enrichment methods, suggesting no adverse impact on most behaviors.