1. The neurochemical characterisation of hypothalamic pathways projecting polysynaptically to brown adipose tissue in the rat.
- Author
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Oldfield BJ, Giles ME, Watson A, Anderson C, Colvill LM, and McKinley MJ
- Subjects
- Adipose Tissue, Brown metabolism, Animals, Axonal Transport physiology, Carrier Proteins metabolism, Efferent Pathways cytology, Herpesvirus 1, Suid physiology, Hypothalamic Hormones metabolism, Hypothalamus cytology, Male, Melanins metabolism, Nerve Tissue Proteins metabolism, Neurons cytology, Orexin Receptors, Orexins, Oxytocin metabolism, Pituitary Hormones metabolism, Pro-Opiomelanocortin metabolism, Rats, Rats, Sprague-Dawley, Receptors, G-Protein-Coupled, Receptors, Leptin, Receptors, Neuropeptide, Spinal Cord cytology, Stellate Ganglion cytology, Thermogenesis physiology, Adipose Tissue, Brown innervation, Efferent Pathways metabolism, Hypothalamus metabolism, Intracellular Signaling Peptides and Proteins, Neurons metabolism, Neuropeptides metabolism, Receptors, Cell Surface, Spinal Cord metabolism, Stellate Ganglion metabolism
- Abstract
The identification of leptin and a range of novel anorectic and orexigenic peptides has focussed attention on the neural circuitry involved in the genesis of food intake and the reflex control of thermogenesis. Here, the neurotropic virus pseudorabies has been utilised in conjunction with the immunocytochemical localisation of a variety of neuroactive peptides and receptors to better define the pathways in the rat hypothalamus directed polysynaptically to the major thermogenic endpoint, brown adipose tissue. Infected neurones were detected initially in the stellate ganglion, then in the spinal cord followed by the appearance of third-order premotor neurones in the brainstem and hypothalamus. Within the hypothalamus these were present in the paraventricular nucleus, lateral hypothalamus, perifornical region, and retrochiasmatic nucleus. At slightly longer survival times virus-infected neurones appeared in the arcuate nucleus and dorsomedial hypothalamus. Neurones in the retrochiasmatic nucleus and in the adjacent lateral arcuate nucleus which project to the brown adipose tissue express cocaine- and amphetamine-regulated transcript, pro-opiomelanocortin and leptin receptors. Neurones in the lateral hypothalamus, a site traditionally associated with the promotion of feeding, project to brown adipose tissue and large numbers of these contained melanin-concentrating hormone and orexin A and B. These data provide part of an anatomical framework which subserves the regulation of energy expenditure.
- Published
- 2002
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