Pupil dilation and behavior as complementary measures of fear response in Mice

The precise assessment of emotional states in animals under the combined influence of multiple stimuli remains a challenge in neuroscience research. In this study, multi-dimensional assessments, including high-precision pupil tracking and behavioral analysis, were conducted to investigate the combined effects of fear stimuli and drug manipulation on emotional responses in mice. Mice exposed to foot shocks showed typical freezing and flight behaviors, but neither of these measures could effectively distinguish between dexmedetomidine, isoflurane, and saline groups. In contrast, the change in pupil diameter clearly distinguished the groups. Our results showed that fear stimulation could induce significant pupil dilation, and dexmedetomidine-isoflurane combined stimulation could significantly inhibit this response, but isoflurane anesthesia alone could not achieve good inhibitory effect. This further demonstrates the superiority of pupil data in resolving the effects of combined stimuli on emotional states and the potential of multidimensional assessments to refine animal disease models and drug evaluations.