Objective To explore the neurogenesis and blood supply in the piriform cortex of rat with vascular dementia after hyperbaric oxygen therapy. Methods SD male rats （ at the age of 2 months） were inflicted by permanent ligation of bilateral carotid arteries （2VO）. In 30 d after the surgery, the animals having a percentage less than 60% in active avoidance response （AAR） in shuttle box testing were identified as suffering from vascular dementia （VD）. Twenty VD rats were divided randomly into 2 groups： VD group and hyperbaric oxygen group [ HBO group, in a tank of 95% oxygen under a pressure of 2.02× 10^5 Pa （2ATA） , 120min/d, for 10 d]. Another 10 normal rats served as control. In 10 d after the treatment, all rats undertook shuttle box testing for their ability of learning and memory. Their regional cerebral blood flow （rCBF） , regional cerebral blood volume （rCBV） and mean transit time （MTF） in the piriform cortex were measured by CT perfusion imaging. The expressions of Nestin and doublecortin （DCX） in the piriform cortex were detected by immunohistoehemical staining. Results There was significant difference in AAR rate of shuttle box testing between HBO group and VD group [ （49.5± 9.3 ） % vs （ 27.5 ± 7.9 ） %, P 〈 0.01 ] ; Significant difference was also seen in AAR rate between VD group and NC group [ （87.5 ± 7.9） %, P 〈 0.01 ]. In VD group, the rCBF was declined, rCBV elevated, and MTF was delayed in comparison with the normal control. While hyperbaric oxygen therapy improved rCBF, decreased rCBV, and shortened MTT compared with VD group. The values of rCBF, rCBV and MTF in HBO group were close to those in normal control. In the piriform cortex, Nestin ＋ cells mostly located in the layer Ⅱ and layer Ⅲ, and the intensity of positive ceils was HBO group 〉 VD group 〉 normal control; DCX ＋ cells were arrayed as a belt mostly in the layer Ⅱ between amygdaline fissure （af） to rhinal fissure （rf）. Conclusion HBO therapy enhances the ability of learning and memory and promotes neurogenesis in the piriform cortex of VD adult rats,

目的探讨血管性痴呆(vascular dementia,VD)大鼠高压氧治疗后梨状皮层(piriform cortex,Pir)神经发生及血液供应情况。方法SD雄性成年大鼠分为正常组、血管性痴呆组(VD组)、血管性痴呆高压氧治疗组(HBO组;高压氧治疗10d),每组10只,CT灌注成像技术检测各组大鼠Pir区局部脑血流量(regional cerebral blood flow,rCBF)、局部脑血容量(regional cerebral blood volume,rCBV)和平均通过时间(mean transit time,MTT),穿梭箱系统检测大鼠学习记忆功能,免疫组化技术研究Pir区Nestin及doublecortin(DCX)表达情况。结果VD组较正常组大鼠Pir区CBF下降,CBV增加,MTT延长;HBO组较VD组Pir区CBF上升,局部CBV下降,MTT缩短;HBO组Pir区CBF、CBV、MTT各值与正常组接近;Pir区Nestin阳性细胞主要位于layerⅡ和layerⅢ,阳性表达强度:HBO组>VD组>正常组;Pir区DCX阳性细胞成条带状,主要位于嗅裂(rf)和杏仁裂(af)之间layerⅡ,阳性表达强度:正常组>HBO组>VD组;HBO组穿梭箱AAR比率(49.5±9.3)%较VD组(27.5±7.9)%显著增高(P<0.01);VD组大鼠AAR比率(27.5±7.9)%显著低于正常组(87.5±7.9)%(P<0.01)。结论高压氧治疗能够改善VD大鼠认知功能障碍并促进Pir区神经发生,此可能和高压氧治疗提高VD大鼠Pir区血液供应有关。

重庆市 自然科学基金(2008AC5119) Supported by the Natural Science Foundation of Chongqing(2008AC5119)