PUBLICATION

Hypocretin/orexin in fish physiology with emphasis on zebrafish

Authors
Panula, P.
ID
ZDB-PUB-090914-16
Date
2010
Source
Acta physiologica (Oxford, England)   198(3): 381-386 (Review)
Registered Authors
Panula, Pertti
Keywords
Hypothalamus, sleep, feeding, dopamine, histamine
MeSH Terms
  • Animals
  • Brain/metabolism
  • Dopamine/metabolism
  • Eating/physiology
  • Fishes/physiology*
  • Food Deprivation/physiology
  • Gene Expression
  • Hypothalamus/physiology
  • Intracellular Signaling Peptides and Proteins/genetics
  • Intracellular Signaling Peptides and Proteins/metabolism*
  • Neuropeptides/genetics
  • Neuropeptides/metabolism*
  • Neurotransmitter Agents/genetics
  • Neurotransmitter Agents/metabolism*
  • Orexin Receptors
  • Orexins
  • RNA, Messenger/metabolism
  • Receptors, G-Protein-Coupled/metabolism
  • Receptors, Neuropeptide/metabolism
  • Sleep/physiology
  • Synaptic Transmission
  • Wakefulness/physiology
  • Zebrafish/physiology*
PubMed
19723028 Full text @ Acta Physiol. (Oxf).
Abstract
One hypocretin/orexin (hcrt) gene has been identified in several fish species. The first pufferfish gene was identified in 2002 and the zebrafish gene was cloned in 2004. Its structure is very similar to that of mammals, and it encodes for two active peptides with C-termini similar to those of mammals. The gene is expressed in the brain in only one hypothalamic nucleus, which sends projections to telencephalon, diencephalon, mesencephalon and rhombencephalon. The terminal fibers are found in close contact with many aminergic cell groups, including those of raphe serotonergic, locus coeruleus noradrenergic, several dopaminergic cell groups and the sole histaminergic hypothalamic cluster. One receptor corresponding to mammalian hcrt 2 receptor has been identified in fish. Overexpression of hcrt in zebrafish has been reported to consolidate wakefulness and inhibit rest. On the other hand, fish lacking the hcrt receptor show short and fragmented sleep instead of sleepiness and cataplexy. Food deprivation increases hcrt mRNA expression in zebrafish brain, and intracerebroventricular hcrt peptides stimulate food consumption and feeding behavior in goldfish. Hcrt peptides thus have important roles in fish physiology. Many genetic and functional methods available render fish, especially zebrafish, a suitable organism to study new aspects of hcrt physiology in vertebrates.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping