Tooth loss has been shown to affect learning and memory in mice and increases the risk of Alz-heimer’s disease. The dentate gyrus is strongly associated with cognitive function. This study hypothesized that tooth loss affects neurons in the dentate gyrus. Adult male mice were random-ly assigned to either the tooth loss group or normal control group. In the tooth loss group, the left maxillary and mandibular molars were extracted. Normal control mice did not receive any intervention. Immunolfuorescence staining revealed that the density and absorbance of double-cortin-and neuronal nuclear antigen-positive cells were lower in the tooth loss group than in the normal control group. These data suggest that tooth loss may inhibit neurogenesis in the dentate gyrus of adult mice.

Houshiheisan is composed of wind-dispelling (chrysanthemun lfower, divaricate saposhnikovia root, Manchurian wild ginger, cassia twig, Szechwan lovage rhizome, and platycodon root) and deifciency-nourishing (ginseng, Chinese angelica, large-head atractylodes rhizome, Indian bread, and zingiber) drugs. In this study, we assumed these drugs have protective effects against cerebral ischemia, on neurovascular units. Houshiheisan was intragastrically administered in a rat model of focal cerebral ischemia. Hematoxylin-eosin staining, transmission electron microscopy, immu-nolfuorescence staining, and western blot assays showed that Houshiheisan reduced pathological injury to the ischemic penumbra, protected neurovascular units, visibly up-regulated neuronal nuclear antigen expression, and down-regulated amyloid precursor protein and amyloid-β42 expression. Wind-dispelling and deifciency-nourishing drugs maintained NeuN expression to varying degrees, but did not affect amyloid precursor protein or amyloid-β42 expression in the ischemic penumbra. Our results suggest that the compound prescription Houshiheisan effectively suppresses abnormal amyloid precursor protein accumulation, reduces amyloid substance depo-sition, maintains stabilization of the internal environment of neurovascular units, and minimizes injury to neurovascular units in the ischemic penumbra.