Hypocretin I in the lateral hypothalamus activates key feeding-regulatory brain sites

Hypocretin I (also referred to as orexin A) administered into the lateral h ypothalamus (LH) stimulates feeding in rats. We undertook the present study to determine the brain regions activated by LH administration of hypocreti n I. Hypocretin administered into the LH significantly elevated cFos-immuno reactivity in the lateral septal area, the central nucleus of the amygdala, the shell of the nucleus accumbens, the bed nucleus of the stria terminali s, the LH, the posterior and dorsomedial hypothalamus, the perifornical, ar cuate and paraventricular nuclei and the nucleus of the solitary tract. The se data indicate that LH hypocretin I communicates with other key energy re gulatory sites within the hypothalamus, the limbic region and the hindbrain , and suggest that these areas are important in the feeding-stimulatory act ions of hypocretin I. NeuroReport 11:103-108 (C) 2000 Lippincott Williams & Wilkins.