Are Orexin Neurons Orexigenic?

Where are the cell bodies of orexin neurons?

lateral hypothalamus

Where is the ‘hunger centre’ of the hypothalamus?

lateral hypothalamus

Where is the ‘satiety centre of the hypothalamus?

ventromedial hypothalamus

What is the role of orexin in feeding bahaviours?

stimulates feeding but also increases energy metabolism

What signals inhibit orexin release?

glucose and leptin

What hormone increases orexin release?

ghrelin

What condition is linked to loss of orexin peptide, neurons or receptors?

narcolepsy/cataplexy

What is the effect of a lesion of the lateral hypothalamus?

apathy, leanness, starvation

What is the effect of electrically stimulating the lateral hypothalamus?

attack, mating, adjunctive behaviours

What is the effect of a lesion in the ventromedial hypothalamus?

obesity

What is the effect of electrically stimulating the lateral hypothalamus in an anaesthetised rat?

stepping