A low-cost mouse cage warming system provides improved intra-ischemic and post-ischemic body temperature control &ndash: application for reducing variability in experimental stroke studies

Abstract

Experimental guidelines have been proposed to improve the rigor and reproducibility of experimental stroke studies in rodents. As brain temperature is a strong determinant of ischemic injury, tight management of brain or body temperature (Tcore) during the experimental protocol is highly recommended. However, little guidance is provided regarding how or for how long temperature support should be provided. We compared a commonly used heat support method (cage on heating pad) with a low-cost custom built warm ambient air cage (WAAC) system. Both heat support systems were evaluated for the middle cerebral artery occlusion (MCAo) model in mice. The WAAC system provided improved temperature control (more normothermic Tcore and less Tcore variation) during the intra-ischemic period (60 min) and post-ischemic period (3 hrs). Neurologic deficit score showed significantly less variance at post-stroke day 1 (PSD1) in WAAC system mice. Mean infarct volume was not statistically different by heat support system, however, standard deviation was 54% lower in the WAAC system group. In summary, we provide a simple low-cost heat support system that provides superior Tcore management in mice during the intra-ischemic and post-ischemic periods, which results in reduced variability of experimental outcomes. HighlightsO_LIWe describe the fabrication of a low-cost mouse cage warming system (warmed ambient air cage; WAAC system) that can be assembled and applied in any stroke laboratory. C_LIO_LIThe WAAC system provides more precise control of post-stroke mouse body temperature compared with traditional heating pad warming system. C_LIO_LIThe more precise control of post-stroke core temperature reduces variability in some experimental measures in more severely injured mice. C_LI