(1) Kd for 2AG (reported Kd for AEA: 500 nM ). (2) Effect size (d1, d2): magnitude of change in neuromodulator levels between groups, estimated e.g. by calculating Cohen’s d: delta of the means of the groups, normalized to the pooled standard deviation . (3) ”High” and “low” affinity denominations are relative (here chosen based on DA/NE systems) and may be shifted for other neuromodulators. (4) Expected future developments. 5HT serotonin, Ach acetylcholine, Ado adenosine, CNO clozapine-N-oxide, C-term C-terminal, DA dopamine, DRD1/DRD2 DA receptor 1 and 2, dFFmax dynamic range (maximal dFF), eCB endocannabinoid, FP fluorescent protein, FSCV fast-scan cyclic voltammetry, GRP gastrin-like peptide, Kd apparent affinity, ND not determined, NE noradrenaline, τ-on/τ-off on- and off-sensor kinetics (half-rise, decay times).