निम्नलिखित में से कौन सा आयन चैनल यादृच्छिक (randomly) रूप से खुलने और बंद होने की स्थिति के बीच बदलता रहता है?

Which digestive hormone inhibits both gastric secretion and motility, stimulates insulin release, and is secreted mainly when fat is present in the duodenum?

The repeated sequence of gradual onset of apnoea followed by gradual restoration of respiration is called ________.