Hyperbaric Oxygen Improves Long-Term Learning and Memory Impairment by Attenuating Neuronal Apoptosis in aMCI Rats

Abstract

Yonggui Zhang,1 Xianzhong Lin,2 Chen Ye,2 Peiling Zhang3 1Department of Anesthesiology, The Second Hospital of Longyan, Fujian, People’s Republic of China; 2Department of Anesthesiology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, People’s Republic of China; 3Department of Anesthesiology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, People’s Republic of ChinaCorrespondence: Xianzhong Lin, Department of Anesthesiology, the First Affiliated Hospital of Fujian Medical University, 20 Chazhong Road, Fuzhou, People’s Republic of China, Email [email protected]: With the aging of the population and the increasing incidence of neurological diseases, amnestic mild cognitive impairment (aMCI) has attracted attention. Hyperbaric oxygen (HBO) has gradually shown the potential in the treatment of aMCI as an emerging treatment method in recent times. This study is to observe the effect of HBO on the long-term learning memory of aMCI rats, and investigate the associated mechanisms.Methods: Seventy-two male rats (4-month-old) were randomly divided into control (CON) group, aMCI group, HBO group, 24 rats in each group. Each group was randomly divided into CON1, CON7, CON28; aMCI1, aMCI7, aMCI28; HBO1, HBO7, HBO28, 8 rats in each group. The aMCI model rats were established in aMCI and HBO groups. HBO group was treated with HBO for 7 days. The ethological and cytopathology which include Morris water maze (MWM) test, HE staining, TUNEL staining and the expression of Fas/FasL on neuron membrane were conducted to evaluate the effects of HBO on day 1, day 7 and day 28 after HBO treatment.Results: MWM test showed that the spatial learning and memory ability of the rats decreased in aMCI group, and recovered in HBO group; Compared with aMCI group, the pathological damage of hippocampal nerve cells was alleviated, the number of apoptotic cells was significantly reduced (P 0.05). However, in aMCI1, aMCI7, and aMCI28 groups gradually aggravated (P < 0.05).Conclusion: 1. HBO can improve the long-term learning and memory impairment by attenuating neuronal apoptosis in aMCI rats. 2. Fas/FasL mediated cell receptor death pathway is involved in the apoptosis of hippocampal neurons.Keywords: amnesic mild cognitive impairment, hyperbaric oxygen, apoptosis, learning and memory impairment

Keywords

• amnesic mild cognitive impairment
• hyperbaric oxygen
• apoptosis
• learning and memory impairment