In the central nervous system, Asiaticoside has been shown to attenuatein vitro neuronal damage caused by exposure toβ-amyloid.In vivo studies demonstrated that Asiaticoside could attenu-ate neurobehavioral, neurochemical and histological changes in transient focal middle cerebral artery occlusion animals. In addition, Asiaticoside showed anxiolytic effects in acute and chronic stress animals. However, its potential neuroprotective properties in glutamate-induced excito-toxicity have not been fully studied. We investigated the neuroprotective effects of Asiaticoside in primary cultured mouse cortical neurons exposed to glutamate-induced excitotoxicity invoked by N-methyl-D-aspartate. Pretreatment with Asiaticoside decreased neuronal cell loss in a con-centration-dependent manner and restored changes in expression of apoptotic-related proteins Bcl-2 and Bax. Asiaticoside pretreatment also attenuated the upregulation of NR2B expression, a subunit of N-methyl-D-aspartate receptors, but did not affect expression of NR2A subunits. Additionally, in cultured neurons, Asiaticoside significantly inhibited Ca2+ influx induced by N-methyl-D-aspartate. These experimental ifndings provide preliminary evidence that during excitotoxicity induced by N-methyl-D-aspartate exposure in cultured cortical neurons, the neu-roprotective effects of Asiaticoside are mediated through inhibition of calcium inlfux. Aside from its anti-oxidant activity, down-regulation of NR2B-containing N-methyl-D-aspartate receptors may be one of the underlying mechanisms in Asiaticoside neuroprotection.

Nestin+neurons have been shown to express choline acetyltransferase (ChAT) in the medial septum-diagonal band of Broca in adult rats. This study explored the projection of nestin+neu-rons to the olfactory bulb and the time course of nestin+neurons in the medial septum-diagonal band of Broca in adult rats during injury recovery after olfactory nerve transection. This study observed that all nestin+neurons were double-labeled with ChAT in the medial septum-diagonal band of Broca. Approximately 53.6%of nestin+neurons were projected to the olfactory bulb and co-labeled with fast blue. A large number of nestin+neurons were not present in each region of the medial septum-diagonal band of Broca. Nestin+neurons in the medial septum and vertical limb of the diagonal band of Broca showed obvious compensatory function. The number of nestin+neurons decreased to a minimum later than nestin-/ChAT+neurons in the medial sep-tum-diagonal band of Broca. The results suggest that nestin+cholinergic neurons may have a closer connection to olfactory bulb neurons. Nestin+cholinergic neurons may have a stronger tolerance to injury than Nestin-/ChAT+neurons. The difference between nestin+and nestin-/ChAT+neurons during the recovery process requires further investigations.