切断外侧嗅束后嗅球中僧帽细胞内B－50（GAP－43）mRNA的表达

ELEVATED EXPRESSION OF B-50 (GAP-43) -mRNA IN A SUBPOPULATION OF OLFACTORY BULB MITRAL CELLS FOLLOWING AXOTOMY

本工作用原位杂交方法研究大鼠嗅球中僧帽细胞（一种ＣＮＳ神经元）损伤后，Ｂ－５０（ＧＡＰ－４３）ｍＲＮＡ表达的变化。结果表明外侧嗅束切断，导致约４０％的僧帽细胞内Ｂ－５０ｍＲＮＡ表达显著增高。持续到损伤后１０ｄ，在损伤后４周已下降至对照水平。而外侧嗅束切断后，大量僧帽细胞逐渐退化。因此本文工作报道嗅球中部分僧帽细胞，具有应答损伤而致细胞内Ｂ－５０ｍＲＮＡ上升的能力。但这种反应并不伴随被切断的嗅束的再生。

Using in-situ hybridization method, We studied B-50 (GAP-43) mRNA expression following lesion of olfactory bulb mitral cells in rats. Expression of B-50 mRNA in approximately 40 % of the mitral cells was upregulated in response to transection of their axons in the lateral olfactory tract (LOT). Enhanced expressin persisted for 10 dayspostlesion but than declined to control levels by 4 weeks after the lesion. A large proportion of the mitral cells gradually degenerated subsequent to LOT transection. Thus, asubpopulation of mitral cells maintain their ability to upregulate B-50, a protein characteristic of growing axons, but enhanced B-50 expression is not accompanied by regeneration of the severed LOT.