Serotonin 5-hT1A receptor activation prevents phosphorylation of NMDA receptor NR1 subunit in cerebral ischemia

J Physiol Biochem. 2007 Sep;63(3):203-11. doi: 10.1007/BF03165783.

Abstract

The mechanisms involved in the neuroprotective effect of serotonin 5-HT1A receptor agonists on brain damage induced by ischemia remain to be fully elucidated. Given that serotonergic drugs may regulate N-methyl-D-aspartate (NMDA) receptor function, which is implicated in events leading to ischemia-induced neuronal cell death, this study sought to determine the effects of the selective 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), on the levels of NMDA receptor NR1 subunit in gerbil hippocampus after transient global cerebral ischemia. Pretreatment with 8-OH-DPAT (1 mg/kg) prevented the neuronal loss in CA1 subfield 72 h after ischemia. NMDA receptor NR1 levels in whole hippocampus were not affected 24 h after ischemia, but the levels of the subunit phosphorylated at the protein kinase A (PKA) site, pNR1(Ser897), were significantly increased, and this increase was prevented by the same 8-OH-DPAT dose, a probable consequence of the increased phosphatase 1 (PP1) enzyme activity found in ischemic gerbils pretreated with the 5-HT1A receptor agonist. The results suggest that NR1 subunit phosphorylation plays a role in the neuroprotective effect of 8-OH-DPAT on cell damage induced by global cerebral ischemia in the gerbil hippocampus and support the potential interest of 5-HT1A receptor activation in the search for neuroprotective strategies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 8-Hydroxy-2-(di-n-propylamino)tetralin / pharmacology*
  • Animals
  • Gerbillinae
  • Hippocampus / metabolism
  • Ischemic Attack, Transient / drug therapy
  • Ischemic Attack, Transient / physiopathology*
  • Male
  • Neuroprotective Agents / pharmacology*
  • Phosphorylation / drug effects
  • Protein Phosphatase 1 / metabolism
  • Receptor, Serotonin, 5-HT1A / metabolism*
  • Receptors, N-Methyl-D-Aspartate / metabolism*

Substances

  • NR1 NMDA receptor
  • Neuroprotective Agents
  • Receptors, N-Methyl-D-Aspartate
  • Receptor, Serotonin, 5-HT1A
  • 8-Hydroxy-2-(di-n-propylamino)tetralin
  • Protein Phosphatase 1