Orexin is a neuropeptide released from the lateral hypothalamus
to adjust food intake, sleep state, autonomous nervous system activity and basal metabolic rate.
This was first illustrated by lesion studies in rodents that indicated that the hypothalamus is crucial in the control of appetite: lesions in the lateral hypothalamus
(LH)  resulted in anorexia, and lesions in the ventromedial hypothalamus (VMH) led to obesity (1).
MCH-null mice are hypophagic and lean, whereas the overexpression of MCH in the lateral hypothalamus
leads to obesity and insulin resistance .
Orexins are produced by the lateral hypothalamus
and evidences have suggested that orexins promote energy expenditure (EE) through modulation of locomotor activity and BAT thermogenesis.
 In this case, starvation and hypoglycemic condition can be termed as a stressor and the stress response was carried out with the help of orexinergic pathway responsible for food intake and motivation/reward, namely the locus ceruleus region of the lateral hypothalamus
where the orexinergic neurons are found in abundance.
Lesions (inflammatory, traumatic, tumours, etc.) in the ventromedial hypothalamus, paraventricular hypothalamus, lateral hypothalamus
or arcuate nucleus may lead to hyperphagia, hormonal deficiencies, low basal metabolism rate, decrement in sleep and cause obesity.
Type 1 receptors are colocalized with corticotrophin-releasing hormone (CRH) in the paraventricular nucleus (PVN), with melanin-concentrating hormone in the lateral hypothalamus
, and with the preproorexin in the ventromedial hypothalamus [2, 3].
The regulatory pathway from the arcuate nucleus (ARC) to the lateral hypothalamus
(LH) may be involved in severe hyperphagia and short-term control of feeding behavior .
The parallel between eating and cognitive changes supports the notion that brain regulation of eating behavior, and in particular the hypothalamic pathways controlling eating homeostasis, are of critical relevance in ALS pathogenesis as further demonstrated by the presence of pathologic TDP-43 inclusions in the lateral hypothalamus
of ALS patients with associated decrease of BMI .
Heisler, "Neuropeptide Y cells represent a distinct glucose-sensing population in the lateral hypothalamus
," Endocrinology, vol.
Over the location in the lateral hypothalamus
, which were initially described, the orexin and its receptors have been highlighted in neuronal bodies and positive fibers present in different regions of the central nervous system (CNS) and their position is in connection with the functions performed.
Past work has linked drug addiction and other reward-seeking behaviors, such as sex and eating, to nerve cells, or neurons, that connect the lateral hypothalamus
to the ventral tegmental area in the brain.