Chlorogenic acid protection of neuronal nitric oxide synthase-positive neurons in the hippocampus of mice with impaired learning and memory☆

BACKGROUND： Clinical practice and modern pharmacology have confirmed that chlorogenic acid can ameliorate learning and memory impairments. OBJECTIVE： To observe the effects of chlorogenic acid on neuronal nitric oxide synthase （nNOS）-positive neurons in the mouse hippocampus, and to investigate the mechanisms underlying the beneficial effects of chlorogenic acid on learning and memory. DESIGN, TIME AND SETTING： The present randomized, controlled, neural cell morphological observation was performed at the Institute of Neurobiology, Central South University between January and May 2005. MATERIALS： Forty-eight female, healthy, adult, Kunming mice were included in this study. Learning and memory impairment was induced with an injection of 0.5 uL kainic acid （0.4 mg/mL） into the hippocampus. METHODS： The mice were randomized into three groups （n = 16）： model, control, and chlorogenic acid-treated. At 2 days following learning and memory impairment induction, intragastric administration of physiological saline or chlorogenic acid was performed in the model and chlorogenic acid-treated groups, respectively. The control mice were administered 0.5uL physiological saline into the hippocampus, and 2 days later, they received an intragastfic administration of physiological saline. Each mouse received two intragastric administrations （1 mL solution once） per day, for a total of 35 days. MAIN OUTCOME MEASURES： Detection of changes in hippocampal and cerebral cortical nNOS neurons by immunohistochemistry; determination of spatial learning and memory utilizing the Y-maze device. RESULTS： At day 7 and 35 after intervention, there was no significant difference in the number of nNOS-positive neurons in the cerebral cortex between the model, chlorogenic acid, and control groups （P 〉 0.05）. Compared with the control group, the number of nNOS-positive neurons in the hippocampal CA1-4 region was significantly less in the model group （P 〈 0.05）. However, the control group was not different fro

Chlorogenic acid protection of neuronal nitric oxide synthase-positive neurons in the hippocampus of mice with impaired learning and memory

chlorogenic acid hippocampus learning and memory impairment nitric oxide synthase