Since LIU Hejian proposed the concept of sweat pore， the theory of sweat pore has experienced accelerated development. Especially with the advances in modern human anatomy and physiology， the microscopic anatomy of sweat pore begins to focus on the intercellular space， ion channels and other membranous space with channels， pores， doors， etc.， which exert the functions of exchanging fluid， information， and energy inside and outside blood vessels and discharging metabolic wastes so as to maintain the normal operation of organs. Therefore， sweat pore is the structural basis for the movement of Qi and the central link of Qi-fluid exchange in the body. The brain， as the house of original spirit， is in charge of the spirit of five Zang-organs. The brain sweat pore is pivotal for the circulation of Qi， blood， and fluid in the brain， and it is the structural basis for the normal physiological functions of the brain. The dysfunction of the brain sweat pore will cause the stagnation of Qi and the abnormal transport of blood and fluid. It will cause the abnormal exchange of Qi， liquid and other material and information， which fail to nourish the original spirt and cause the loss of vital activity， eventually leading to consciousness and emotion disorders. The treatment should focus on opening the brain sweat pore， smoothing the exchange of Qi and fluid inside and outside the pore， and restoring the Qi movement， so as to cure encephalopathy. At present， western medicine treatment of encephalopathy needs to solve the problem of drug efflux from the blood-brain barrier and improve the effective concentration of drugs into the brain. The structure and function of brain sweat pore is similar to those of the blood-brain barrier. The aromatic resuscitative medicines and wind-extinguishing medicines can open the brain sweat pore. When being combined with other medicines， they can lead the medicine to enter the brain to restore the Qi movement of the brain sweat pore and enhance the therapeutic effect. Liver-pacifying wind-extinguishing medicines， insect medicines， tonifying medicines， heat-clearing toxin-removing medicines， and damp-draining medicines can treat pathological factors such as wind， phlegm， stasis， deficiency， toxin， and dampness， respectively. These medicines， combined with the medicines with the tropism to brain meridians， can open the brain sweat pore and guide the medicine into the brain to enhance the effective concentration of the medicine， thereby enhancing the efficacy against encephalopathy.

ObjectiveTo study the effects of Huangjing Jiannao granules on learning and memory abilities and cerebral blood flow in the rat model of vascular cognitive impairment （VCI） and to explore the mechanism of Huangjing Jiannao granules in the treatment of VCI. MethodSeventy-two SPF-grade male SD rats were randomly selected， with 12 rats as the sham operation group. The remaining rats were subjected to bilateral carotid artery ligation （2-VO） for the modeling of VCI. According to the randomized block design， the successfully modeled rats were grouped as follows： model， donepezil hydrochloride （0.50 mg·kg^-1）， and low-， medium-， and high-dose （2.36， 4.72， 9.44 g·kg^-1， respectively） Huangjing Jiannao granules. After 6 weeks of treatment， Morris water maze test and new object recognition test were conducted to evaluate the learning and memory abilities of the rats. After continuous gavage for 8 weeks， the cerebral blood flow was recorded by a laser microcirculation blood flow imager， and the survival and injury of hippocampal neurons were observed by Nissl staining. The expression of neuronal nuclear antigen （NeuN） in the hippocampus was detected by immunohistochemistry （IHC）. The levels of interleukin-1β （IL-1β） and tumor necrosis factor-α （TNF-α） in the serum were determined by enzyme-linked immunosorbent assay. The protein levels of phosphatidylinositol 3-kinase （PI3K）， phosphorylated protein kinase B （p-Akt）， nuclear factor-κB p65 （NF-κB p65）， and nuclear factor-κB inhibitor α （IκBα） in the hippocampus were determined by Western blot. ResultCompared with the sham operation group， the model group showed weakened learning and memory abilities （P<0.01）， reduced blood flow in the whole brain， forebrain， and hindbrain （P<0.01）， damaged neurons and reduced survived neurons in the hippocampal CA1 region （P<0.01）， down-regulated expression of NeuN （P<0.01）， elevated levels of IL-1β and TNF-α in the serum （P<0.01）， up-regulated protein levels of PI3K， p-Akt， and NF-κB p65 in the hippocampal tissue， and down-regulated protein level of IκBα （P<0.01）. Compared with the model group， medium- and high-dose Huangjing Jiannao granules improved the learning and memory abilities （P<0.05，P<0.01）. High-dose Huangjing Jiannao granules increased the blood flow in the whole brain， forebrain， and hindbrain （P<0.05，P<0.01）， and medium-dose Huangjing Jiannao granules increased the blood flow in the whole brain （P<0.05）. All the doses of Huangjing Jiannao granules increased the number of survived neurons （P<0.05，P<0.01） and up-regulated the protein level of NeuN （P<0.05，P<0.01）. Medium and high-dose Huangjing Jiannao granules lowered the level of TNF-α （P<0.05，P<0.01）， down-regulated the protein levels of PI3K， p-Akt， and NF-κB p65 （P<0.05，P<0.01）， and up-regulated the protein level of IκBα （P<0.01）. ConclusionHuangjing Jiannao granules can improve the learning and memory abilities and promote the recovery of cerebral blood flow in the rat model of VCI induced by 2-VO by regulating the expression of proteins involved in the PI3K/Akt signaling pathway， inhibiting inflammation， and reducing hippocampal neuron injury.