Taurine rescues hippocampal long-term potentiation from ammonia-induced impairment

Neurobiol Dis. 2006 Sep;23(3):512-21. doi: 10.1016/j.nbd.2006.04.006.

Abstract

Hyperammonemia, a major pathophysiological factor in hepatic encephalopathy, impairs long-term potentiation (LTP) of synaptic transmission, a cellular model of learning and memory, in the hippocampus. We have now studied the protective action of taurine on this paradigm by analyzing LTP characteristics in mouse hippocampal slices treated with ammonium chloride (1 mM) in the presence of taurine (1 mM), an ubiquitous osmolyte, antioxidant, and neuromodulator, as well as other substances with such properties. Ammonia-treated slices displayed a significant impairment of LTP maintenance. Taurine and the mitochondrial enhancer l-carnitine, but not the antioxidants (ascorbate, carnosine, and the novel compound GVS-111) or the osmolyte betaine prevented this impairment. The protective effect of taurine was preserved under the blockade of inhibitory GABA(A) and glycine receptors. It is suggested that taurine may rescue the mechanisms of hippocampal synaptic plasticity by improving mitochondrial function under hyperammonemic conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonium Chloride / antagonists & inhibitors
  • Animals
  • Carnitine / pharmacology
  • Energy Metabolism / drug effects
  • Energy Metabolism / physiology
  • Hepatic Encephalopathy / drug therapy*
  • Hepatic Encephalopathy / metabolism
  • Hepatic Encephalopathy / physiopathology
  • Hippocampus / drug effects*
  • Hippocampus / metabolism
  • Hippocampus / physiopathology
  • Hyperammonemia / drug therapy*
  • Hyperammonemia / metabolism
  • Hyperammonemia / physiopathology
  • Long-Term Potentiation / drug effects*
  • Long-Term Potentiation / physiology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Neuroprotective Agents / metabolism
  • Neuroprotective Agents / pharmacology*
  • Neuroprotective Agents / therapeutic use
  • Organ Culture Techniques
  • Receptors, GABA-A / drug effects
  • Receptors, GABA-A / metabolism
  • Receptors, Glycine / drug effects
  • Receptors, Glycine / metabolism
  • Taurine / metabolism
  • Taurine / pharmacology*
  • Taurine / therapeutic use

Substances

  • Neuroprotective Agents
  • Receptors, GABA-A
  • Receptors, Glycine
  • Ammonium Chloride
  • Taurine
  • Carnitine