Fig. 4.

Firing properties of calyx terminals. A: firing pattern was regular in a CZ calyx terminal, resulting in tighter clustering of interspike intervals (ISIs) (B) and a coefficient of variation (CV) of 0.14. ISIs were more variable in a different CZ calyx terminal where firing pattern was irregular (C and D) and CV was 0.4. E: although 3 PZ calyces showed the most regular firing pattern and smallest CVs (open triangles, bottom left), both CZ and PZ calyx terminals showed a range of firing patterns. The frequency of action potential firing ranged from 1.3 to 63 Hz (F).