Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Histograms showing the percentage of cardiac intervals in which a unit generated 1, 2, 3, 4 or 5 spikes at rest (A) or during the static phase of an inspiratory-capacity apnoea (B). Only those cardiac intervals in which the units were active are included; data pooled from 9 units studied in both conditions.
