Abstract

Systemic inflammation exerts detrimental effects on the various organs, especially on the central nervous system (CNS), and leading to multiple organ failure. Lipopolysaccharide (LPS) is a lipid-containing polysaccharide which is endotoxin and acts as important group-specific antigen. LPS induces immune activation, causes inflammation, and results in deterioration of cellular function. Hippocampal neurons are particularly susceptible to this LPS. Treadmill exercise is known to ameliorate neurologic impairment induced by various brain insults. In the present study, we investigated the effects of treadmill exercise on short-term and spatial memories in relation with apoptotic neuronal cell death in the hippocampus following LPS-induced systemic inflammation. For the evaluation of age-dependent effect of treadmill exercise on these parameters, we used both young-aged and old-aged rats. In the present results, aging process impaired short-term and spatial memories through increase of apoptosis in the hippocampus. Treadmill exercise alleviated aging-induced impairment of short-term and spatial memories and suppressed aging-induced apoptosis in the old-aged rats. LPS-induced systemic inflammation disturbed short-term and spatial memories with increased apoptosis in both young-aged and old-aged rats. Treadmill exercise alleviated LPS-induced impairment of short-term and spatial memories and suppressed LPS-induced apoptosis in both young-aged and old-aged rats. Here in this study, we showed that treadmill exercise may inhibit LPS-induced neuronal apoptosis, thus facilitates recovery of memory function following systemic inflammation. Concerning that aging process disturbs memory function by enhancing of apoptotic neuronal cell death, these effects of treadmill exercise may be more important in the elderly. (Korean J Str Res 2011;19:97∼105)

• Keywords: Lipopolysaccharide, Treadmill exercise, Hippocampus, Apoptosis, Memory