Reduced Number of Hypocretin Neurons in Human Narcolepsy TC Thannickal et al., Neuron 27; 469 2000 Distribution of Cells in Perifornical and Dorsomedial Hypothalamic Regions of Normal and Narcoleptic Humans • On average, narcoleptics have 7% of the Hcrt cells seen in normals • C and D – low power covering regions shown in grey at top • E and G – normal subjects • F and H – narcoleptic subjects • Most human narcolepsy is NOT familial; is discordant in identical twins; and NOT linked to mutations in hypocretin.