Linville D G, Williams S, Arneric S P
Department of Neurobiology, Montreal Neurological Institute, Quebec, Canada.
Brain Res. 1993 Sep 17;622(1-2):26-34. doi: 10.1016/0006-8993(93)90797-q.
To determine whether intrinsic cortical neurons participate in mediating increases in cortical cerebral blood flow (CBF) in response to electrical stimulation of the basal forebrain (BF), cortical CBF was assessed by laser-Doppler flowmetry in rats before and after unilaterally removing local cortical neurons with the excitotoxin ibotenic acid (IBO). On the first day of testing, CBF responses to right and left BF stimulation were nearly identical in right and left frontal cortices, corresponding to the frequency of stimulation, up to a maximum at 25 Hz (+180%). Subsequently, animals received a unilateral microinjection of IBO and a contralateral microinjection of phosphate-buffered saline (PBS) into the responsive cortical sites. After five days, responses in lesioned cortices were remarkably intact both in comparison to the contralateral PBS-injected site and to the same site tested prior to lesioning on day 1. IBO lesions of the response sites were histologically confirmed to extend through the entire depth of the frontal cortex and to encompass a large surface area (7.7 +/- 0.5 mm2). These results indicate that local cortical neurons are not critical to the mediation of increases in cortical CBF as elicited by BF stimulation. This study further supports the role of the BF as a distinct intracerebral neurogenic regulator of cortical CBF.
为了确定大脑皮质内神经元是否参与介导大脑皮质脑血流量（CBF）的增加以响应基底前脑（BF）的电刺激，在大鼠单侧用兴奋性毒素鹅膏蕈氨酸（IBO）去除局部皮质神经元之前和之后，通过激光多普勒血流仪评估皮质CBF。在测试的第一天，右额叶皮质和左额叶皮质中对左右BF刺激的CBF反应几乎相同，与刺激频率相对应，在25Hz时达到最大值（+180%）。随后，动物在响应性皮质部位接受单侧微注射IBO，并在对侧微注射磷酸盐缓冲盐水（PBS）。五天后，与对侧注射PBS的部位以及在第1天损伤前测试的同一部位相比，损伤皮质中的反应明显完整。通过组织学证实，反应部位的IBO损伤延伸至额叶皮质的整个深度，并覆盖较大的表面积（7.7±0.5平方毫米）。这些结果表明，局部皮质神经元对于介导由BF刺激引起的皮质CBF增加并不关键。本研究进一步支持了BF作为皮质CBF独特的脑内神经源性调节因子的作用。
