title: Desalted deep-sea water improves cognitive function in mice by increasing the production of insulin-like growth factor-I in the hippocampus.
abstract: The stimulation of sensory neurons in the gastrointestinal (GI) tract improves cognitive function by increasing the hippocampal production of insulin-like growth factor-I (IGF-I) in mice. In the current study, we examined whether oral administration of desalted deep-sea water (DSW) increases the hippocampal production of IGF-I by stimulating sensory neurons in the GI tract, thereby improving cognitive function in mice. Desalted DSW increased calcitonin gene-related peptide (CGRP) release from dorsal root ganglion (DRG) neurons isolated from wild-type (WT) mice by activating transient receptor potential vanilloid 1. The plasma levels of IGF-I and tissue levels of CGRP, IGF-I, and IGF-I mRNA in the hippocampus were increased by oral administration of desalted DSW in WT mice. In these animals, nociceptive information originating from the GI tract was transmitted to the hippocampus via the spinothalamic pathway. Improvement of spatial learning was observed in WT mice after administration of desalted DSW. Distilled DSW showed results similar to those of desalted DSW in vitro and in vivo. None of the effects of desalted DSW in WT mice were observed after the administration of desalted DSW in CGRP-knockout (CGRP-/-) mice. No volatile compounds were detected in distilled DSW on GC-MS analysis. These observations suggest that desalted DSW may increase the hippocampal IGF-I production via sensory neuron stimulation in the Gl tract, thereby improving cognitive function in mice. Such effects of desalted DSW might not be dependent on the minerals but are dependent on the function of the water molecule itself.
authors.affiliation: Department of Translational Medical Science Research, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Naoaki
authors.initials: N
authors.lastname: Harada
authors.forename: Juan
authors.initials: J
authors.lastname: Zhao
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kurihara
authors.forename: Naomi
authors.initials: N
authors.lastname: Nakagata
authors.forename: Kenji
authors.initials: K
authors.lastname: Okajima
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D003071:Cognition; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D016762:Genes, fos; D006624:Hippocampus / Q000098:blood supply / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D055495:Neurogenesis; D012333:RNA, Messenger / Q000032:analysis; D012623:Seawater / Q000032:analysis
chemical_list: D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I; D015740:Calcitonin Gene-Related Peptide