Effects of thioperamide, a histamine H3 antagonist, on the step-through passive avoidance response and histidine decarboxylase activity in senescence-accelerated mice

Pharmacol Biochem Behav. 1995 Mar;50(3):321-5. doi: 10.1016/0091-3057(95)00248-u.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / metabolism*
  • Animals
  • Avoidance Learning / drug effects*
  • Histamine Antagonists*
  • Histidine Decarboxylase / drug effects*
  • Male
  • Mice
  • Mice, Inbred Strains
  • Piperidines / pharmacology*


  • Histamine Antagonists
  • Piperidines
  • Histidine Decarboxylase
  • thioperamide