A portion of VMH neurons also express cholecystokinin receptor B (CCKBR), and optogenetic stimulation of CCKBR-expressing neurons in the VMH (VMHCCKBR) promotes hyperglycaemia primarily by increasing circulating catecholamines and glucocorticoids levels, but independent of islet cells – levels of glucagon and insulin are stable during stimulation [143]. Here, GCG is linked to Hyperglycemia.