title: Effects of thioperamide, a histamine H3 antagonist, on the step-through passive avoidance response and histidine decarboxylase activity in senescence-accelerated mice.
abstract: The effect of thioperamide, a histamine H3 receptor antagonist, on learning and memory was studied in the senescence-accelerated mice-prone strain (SAM-P/8) and normal-rate aging strain (SAM-R/1). In a passive avoidance test, SAM-P/8 mice of 12 months showed significant impairment of learning and memory compared with SAM-R/1 mice of the same age. Thioperamide significantly improved the response latency in SAM-P/8 mice when injected intraperitoneally at a dose of 15 mg/kg. The histidine decarboxylase (HDC) activity in the forebrain was significantly lower in SAM-P/8 mice than in SAM-R/1 mice. Thioperamide administration significantly potentiated HDC activity in the forebrain of SAM-P/8 mice as well as improving learning and memory. These results suggest that central histaminergic neurons may be involved in learning and memory impairment of SAM-P/8 mice, although other possibilities are not ruled out.
authors.affiliation: Department of Geriatric Medicine, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Meguro
authors.forename: K
authors.initials: K
authors.lastname: Yanai
authors.forename: N
authors.initials: N
authors.lastname: Sakai
authors.forename: E
authors.initials: E
authors.lastname: Sakurai
authors.forename: K
authors.initials: K
authors.lastname: Maeyama
authors.forename: H
authors.initials: H
authors.lastname: Sasaki
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D006633:Histamine Antagonists; D006640:Histidine Decarboxylase / Q000187:drug effects*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D010880:Piperidines / Q000494:pharmacology*
chemical_list: D006633:Histamine Antagonists; D010880:Piperidines; D006640:Histidine Decarboxylase; C052075:thioperamide