After
decerebration, the square piece of skull previously
removed was put back into place and sealed with
bone wax. A rubber patch (2×3 cm) was secured with sutures and superglue over the opening
in the skull. The fish was then placed in a
plexiglas chamber with a flow of aerated, dechlorinated
water and allowed to recover from surgery
and anesthesia overnight. Pilot experiments
showed that after recovery, decerebrate fish show
normal ventilation and ventilatory responses to
external NaCN (500 g) and aquatic hypoxia
(40 Torr PO2). The day after surgery, the fish
was removed from the chamber and prepared for
nerve recording.