Summary: This protocol provides two independent methods to functionally detect the neuronal expression of CO2-sensitive hemichannels. These hemichannels (consisting of connexins 26 or 30) are directly gated by CO2. independent of pH changes and until recently were thought to be only expressed by glia. This protocol outlines a method to change the concentration of CO2 without changing pH. https://spencertifieders.shop/product-category/video-splitters/