title: Taurine rescues hippocampal long-term potentiation from ammonia-induced impairment.
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.
authors.affiliation: Department of Neurophysiology, Heinrich-Heine University, POB 101007, D-40001 Düsseldorf, Germany.
authors.forename: Aisa N
authors.initials: AN
authors.lastname: Chepkova
authors.forename: Olga A
authors.initials: OA
authors.lastname: Sergeeva
authors.forename: Helmut L
authors.initials: HL
authors.lastname: Haas
mesh_terms: D000643:Ammonium Chloride / Q000037:antagonists & inhibitors; D000818:Animals; D002331:Carnitine / Q000494:pharmacology; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D006501:Hepatic Encephalopathy / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D022124:Hyperammonemia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D017774:Long-Term Potentiation / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D018696:Neuroprotective Agents / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D009924:Organ Culture Techniques; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism; D018009:Receptors, Glycine / Q000187:drug effects / Q000378:metabolism; D013654:Taurine / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D018696:Neuroprotective Agents; D011963:Receptors, GABA-A; D018009:Receptors, Glycine; D000643:Ammonium Chloride; D013654:Taurine; D002331:Carnitine