Fig. 6. Fear conditioning performance 8 weeks after 0-h, 1-h, 2-h, or 4-h isoflurane (iso) or 4-h carbon dioxide (CO2) at postnatal day (P)7. Isoflurane given to P7 rats for 2 h or 4 h decreased baseline freezing ( A ) but not pretone test freezing ( C ). Tone-shock pairings resulted in short-term memory formation ( B ). There was a difference in neither the hippocampal-independent tone portion of the test ( D ) nor the hippocampal-dependent context portion ( E ). Data are medians with interquartile ranges. ** P < 0.01, Kruskall-Wallis test with Dunn’s correction.