Indexed behavioral response scores (range 0–2) as a function of percent isoflurane level (on a log scale) for Dahl salt-sensitive (SS, dashed line) and Brown Norway (BN, solid line) rats are illustrated with upper and lower confidence levels. SS behavior was more sensitive to isoflurane than BN as shown by lower half-maximal concentrations during all behavioral tests. (A) Vibrissal stroking responses disappear early and rapidly during induction with isoflurane, but vibrissal responses were obtunded at higher concentrations in BN compared to SS rats during induction and emergence from isoflurane anesthesia. (B, C) Olfactory and corneal responses were more resistant to isoflurane, yet SS rats were more likely to lose these responses, and the half-maximal isoflurane was significantly less than BN. (D) Loss of righting reflex was more resistant to isoflurane during induction and more compliant during emergence, and the half-maximal concentration of isoflurane was significantly less in SS compared to BN rats, especially during emergence. *P ≤ 0.05 SS versus BN.