HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 35/1/5    most recent 90221.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ellefsen, S. Articles by Nilsson, G. E. Search for Related Content PubMed PubMed Citation Articles by Ellefsen, S. Articles by Nilsson, G. E.

Call For Papers: Comparative Genomics

Expression of genes involved in excitatory neurotransmission in anoxic crucian carp (Carassius carassius) brain

¹ Physiology Programme, Department of Molecular Biosciences, University of Oslo, Oslo
² Lillehammer University College, Lillehammer
³ Cancer and Surgical Division, Ullevål University Hospital, Oslo
⁴ Gene Programme, Department of Molecular Biosciences, University of Oslo, Oslo, Norway

The crucian carp, Carassius carassius, survives months without oxygen. During anoxia it needs to keep energy expenditure low, particularly in the brain, with its high rate of ATP use related to neuronal activity. This could be accomplished by reducing neuronal excitability through altered expression of genes involved in excitatory neurotransmission. Through cloning and the use of a recently developed real-time RT-PCR approach, with an external RNA control for normalization, we investigated the effect of 1 and 7 days of anoxia (12°C) on the expression of 29 genes, including 8 3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor subunits, 6 N-methyl-D-aspartate (NMDA) receptor subunits, 7 voltage-gated sodium and calcium channels, 4 glutamate transporters, and 4 genes involved in NMDA receptor-mediated neuroplasticity. The subunits of the majority of the gene families had expression profiles similar to those observed in the mammalian brain and showed remarkably stable expression during anoxia. This suggests that the genes may have similar functions in crucian carp and mammals, and that the excitatory abilities of the crucian carp brain are retained during anoxia. Although the data generally argue against profound neural depression ("channel arrest"), NMDA receptor subunit (NR) expression showed features that could mediate reduced neural excitability. Primarily, the NR2 subunit expression, which was dominated by NR2B and NR2D, resembled that seen in hypoxia-tolerant neonatal rats, and decreased anoxic expression of NR1, NR2C, and NR3A indicated reduced numbers of functional NMDA receptors. We also report the full-length sequence of crucian carp NR1 mRNA and a novel NR1 splice cassette introducing an N-glycosylation site into the extracellular S1S2 domain.

N-methyl-D-aspartate/3-hydroxy-5-methyl-4-isoxazole propionate receptors; voltage-gated ion channels; glutamate transporter; anoxia; external RNA control

This article has been cited by other articles:

				S. Ellefsen, K.-O. Stenslokken, C. E. Fagernes, T. A. Kristensen, and G. E. Nilsson Expression of genes involved in GABAergic neurotransmission in anoxic crucian carp brain (Carassius carassius) Physiol Genomics, January 8, 2009; 36(2): 61 - 68. [Abstract] [Full Text] [PDF]

				H. M. Prentice The major contribution of brain GABAergic function to anoxic survival Physiol Genomics, January 8, 2009; 36(2): 59 - 60. [Full Text] [PDF]