Transcardial injection and vascular distribution of microalgae in Xenopus laevis as means to supply the brain with photosynthetic oxygen

Oxygen in vertebrates is generally provided through respiratory organs and blood vessels. This protocol describes transcardial injection, vascular distribution, and accumulation of phototrophic microalgae in the brain of Xenopus laevis tadpoles. Following tissue isolation, oxygen dynamics and neuronal activity are recorded in semi-intact whole-head preparations. Illumination of such microalgae-filled preparations triggers the photosynthetic production of oxygen in the brain that, under hypoxic conditions, rescues neuronal activity. This technology is potentially able to ameliorate consequences of hypoxia under pathological conditions. For complete details on the use and execution of this protocol, please refer to Özugur et al. (2021).