A development of a new method for continuous measurement of regional cerebral blood flow and analysis of the regulation of cerebral blood flow in a conscious rat.

1.我们开发了一种新的系统，可以使用激光多普勒血流仪连续测量有意识大鼠皮层的区域血流（rCBF）。在麻醉下，打开动物的头骨，在上面开一个小的方形洞，然后在洞上放一个透明的丙烯酸板。将聚乙烯套管固定在钢板上，作为激光多普勒流量计（LDF）探头的导向。钢板套管和引导套管均用牙水泥固定在颅骨上。麻醉恢复后，有意识的动物被放在吊床上，腿牢牢地贴着地板。该系统被推荐用于有意识动物rCBF的连续测量。用这种方法连续测量清醒大鼠行走过程中的rCBF。在慢行（4cm/s） 30 s时，额叶、顶叶和枕叶皮质的rCBF增加。rCBF在三个皮层中的反应几乎相同。步行引起的皮质rCBF增加可通过全身给予血脑屏障（BBB）渗透性毒蕈碱和烟碱能受体拮抗剂部分减少，但不受血脑屏障不渗透性药物的影响。这表明毒蕈碱受体和烟碱受体都参与中枢神经系统的rCBF反应。我们还可以证明，在有意识的大鼠以温和的速度行走时，大脑皮层的细胞外乙酰胆碱增加。间接地，这些数据表明，行走引起的皮质rCBF增加，至少部分是源于Meynert基底核的皮质胆碱能血管扩张系统的激活。

1.We have developed a new system to continuously measure regional blood flow (rCBF) in the cortex of a conscious rat using laser Doppler flowmetry.Under anesthesia, the animal's skull was opened making a small square hole and a transparent acrylic plate was placed over the hole.A polyethylene cannula was fixed on the plate as a guide for the laser Doppler flowmeter (LDF) probe.Both the plate and guide cannula were fixed to the skull by dental cement.After recovery of anesthesia, the conscious animal was placed in a hammock with their legs firmly touching the floor.This system is recommended for the continuous measurement of rCBF in a conscious animal.Using this method, rCBF in conscious rats was continuously measured during walking.rCBF in the frontal, parietal, and occipital corticies increased during walking at a mild speed (4cm/s) for a period of 30 s.The responses of rCBF in the three corticies were almost identical.Walking-induced increase in cortical rCBF was partially reduced by systemic administration of both blood brain barrior (BBB) -permeable muscarinic and nicotinic cholinergic receptor antagonists, but was unaffected by BBB-impermeable drugs.This suggests the involvement of both muscarinic and nicotinic receptors in the rCBF responses in the central nervous system.We could also demonstrate that extracellular acetylcholine in the cerebral cortex increased during walking at a mild speed in conscious rats.Circumstantially, these data suggest that the walking-induced increase in cortical rCBF is, at least in part, to activation of the cholinergic vasodilative system in the cortex originating in the nucleus basalis of Meynert.