Figure 1.

In vivo H₂S-induced suppression of brain activity was concomitant with apnea. Mice were preimplanted with electrodes for EEG and EKG. Breathing activity was recorded by plethysmography. In vivo H₂S exposure paradigm was shown in A. After brief calibration of plethysmograph and recordings of biopotentials of baseline activity, mice were exposed to normal breathing air or 1000 ppm H₂S (B) until death as assesses by EKG. Baseline recordings displayed EEG, EKG, and plethysmography traces of mice at rest. Recording 1 shows 90 s signal recordings at about 5 min from the start of gas exposure, while Recording 2 shows 90 s signal recordings at about 35 min from the start of gas exposure. Recordings 1 and 2 display typical suppression of EEG and plethysmography in H₂S exposed mice (B). Note the H₂S-induced electrocerebral suppression and respiratory arrest while cardiac activity persisted (B, Recordings 1 and 2). N = 3 mice. Abbreviations: EEG, electroencephalogram; EKG, electrocardiogram; H₂S, hydrogen sulfide.