Fig. 4.

Membrane potential and firing frequency are preserved beyond network failure in hypoxia. Motoneurons in the semi-intact preparation (A) were analyzed regarding membrane potential and firing in response to a 1000-pA step current (max firing frequency). Recordings in baseline conditions (BL, left B/F) were compared to 10 min after the network output collapsed due to hypoxia in controls (n=10, right; B) or after 40 min of hypoxia exposure (active network) in overwintered frogs (n=12, right; E). This is exemplified by individual recordings in B and E. Hypoxia exposure did not change (p>0.05, paired t-test) membrane potential or max firing frequency in controls (C and D) or overwintered (F and G) motoneurons