How does atomoxetine affect cognitive test performance in mice with different brain weights?

Atomoxetine (AT) is an inhibitor of the noradrenaline transporter, which induces behavioral changes presumably caused by the increase in brain noradrenaline levels. The study investigates the effects of atomoxetine on cognitive test performance in two mouse strains differing in relative brain weight: large brain (LB) mice and small brain (SB) mice. LB mice typically demonstrate higher cognitive abilities, while SB mice show higher anxiety and stress-reactivity.

Atomoxetine affects cognitive test performance differently in LB and SB mice. In the puzzle-box cognitive test, LB mice treated with atomoxetine were less successful at task solutions, possibly because they were less afraid of the brightly lit test box. In contrast, SB mice treated with atomoxetine were more successful at solving the task. This suggests that atomoxetine may influence cognitive performance based on the baseline brain weight and associated behavioral traits of the mice.