Development and evaluation of a climbing test in mice: A novel approach for assessing pain-related behaviour

<b>Background and aims:</b> The development of new analgesics is challenged by a low translation rate from preclinical models to a clinical setting, partially<br/>due to the reliance on evoked measures, which are inherently susceptible to bias. Painful conditions often make themselves known when performing<br/>everyday tasks, altering normal behaviour. We are validating a climbing test for assessing impairment of normal function in mice, serving as a measure of<br/>non-evoked pain-like behaviour. Our goal is to increase the translational value of preclinical experiments.<br/><b>Methods:</b> We have established a climbing test, based on Santos et al. (Frontiers in Pain Research, 2023), which involves recording a mouse voluntarily<br/>climbing on a cylindrical vertical mesh grid for 10 minutes. A decrease in the frequency, duration, or distance of climbs, demonstrates the impact of pain on<br/>natural behaviour. We used the plantar incision model of post-surgical pain and evaluated if the NSAID meloxicam reinstates natural climbing.<br/><b>Results:</b> This experiment is currently being completed, and data analysis is underway, with expected finalisation well before EFIC2025. Our preliminary<br/>results suggest that the plantar incision model impairs climbing behaviour only moderately, with results pending for the mitigating effects of meloxicam.<br/><b>Conclusions:</b> The climbing test is a promising, behaviourally relevant, non-evoked test for assessing pain-related behaviour in mice, with a potential for<br/>enhancing the translational value of preclinical pain assessment. Preliminary results suggest only mild impairment from the plantar incision model, but<br/>future research will assess the outcome in other models.