title: The effects of oral taurine administration on behavior and hippocampal signal transduction in rats.
abstract: Taurine, 2-aminoethylsulfonic acid, is one of the most abundant amino acids in the brain. It has various important physiological functions as a neuromodulator and antioxidant. Taurine is expected to be involved in depression; however, knowledge regarding its function in relation to depression is limited. In this study, we attempted to elucidate the effects of oral taurine administration on antidepressant-like behaviors in rats and depression-related signal transduction in the hippocampus. In behavioral tests, rats fed a high taurine (HT: 45.0 mmol/kg taurine) diet for 4 weeks (HT4w) showed decreased immobility in the forced swim test (FS) compared to controls. However, rats fed a low taurine (LT: 22.5 mmol/kg taurine) diet for 4 weeks or an HT diet for 2 weeks (HT2w) did not show a significant difference in FS compared to controls. In biochemical analyses, the expression of glutamic acid decarboxylase (GAD) 65 and GAD67 in the hippocampus was not affected by taurine administration. However, the phosphorylation levels of extracellular signal-regulated kinase1/2 (ERK1/2), protein kinase B (Akt), glycogen synthase kinase3 beta (GSK3β) and cAMP response element-binding protein (CREB) were increased in the hippocampus of HT4w and HT2w rats. Phospho-calcium/calmodulin-dependent protein kinase II (CaMKII) was increased in the hippocampus of HT4w rats only. Moreover, no significant changes in these molecules were observed in the hippocampus of rats fed an HT diet for 1 day. In conclusion, our findings suggest that taurine has an antidepressant-like effect and an ability to change depression-related signaling cascades in the hippocampus.
authors.affiliation: College of Agriculture, Ibaraki University, Ami, Ibaraki 300-0393, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Iio
authors.forename: Noriko
authors.initials: N
authors.lastname: Matsukawa
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Tsukahara
authors.forename: Atsushi
authors.initials: A
authors.lastname: Toyoda
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001522:Behavior, Animal / Q000187:drug effects*; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000235:genetics / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism; D003863:Depression / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D004032:Diet; D015870:Gene Expression / Q000187:drug effects; D005968:Glutamate Decarboxylase / Q000235:genetics / Q000378:metabolism; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D013550:Swimming; D013654:Taurine / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D000928:Antidepressive Agents; D017362:Cyclic AMP Response Element-Binding Protein; D013654:Taurine; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D051057:Proto-Oncogene Proteins c-akt; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; C535149:Mapk1 protein, rat; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D038362:Glycogen Synthase Kinase 3; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1; C401141:glutamate decarboxylase 2