Most, if not all, DREADDs papers talk about i.p. injection of CNO, but we would like to do i.v. injection. Are there any sources for dosing of CNO or clozapine in rats?
1 mg/kg see seems pretty standard. That's what I use and get robust results. With such a dose you get minimal (sub-threshold) conversion to clozapine, which could affect your results, especially if you are testing behavior.
See, e.g., Article Chemogenetics revealed: DREADD occupancy and activation via ...