Fig. 1.

Heart rate (HR). Responses in anesthetized control animals exposed to hyperbaric oxygen (HBO₂) at 6 atmospheres absolute (ATA) were biphasic for control groups, artificial cerebral spinal fluid (aCSF; A) or aCSF + DSMO (B), decreasing at first, followed by increases that peaked ∼15–20% above baseline by the end of hyperbaric exposure. In animals with central NOS inhibition, decreases in HR were sustained throughout the 60-min hyperbaric exposure. *P < 0.05 vs. air; #P < 0.05 vs. control (aCSF or aCSF + DSMO) compared at same time points.