【摘要】 目的 觀察在不同劑量乙醇作用下大鼠下丘腦和脊髓神經(jīng)細胞P物質(zhì)的表達情況和掃描電子顯微鏡（SEM）下神經(jīng)細胞的形態(tài)學變化，探討乙醇作用下大鼠行為學改變的相關機制。 方法 通過福爾馬林實驗觀察大鼠在不同劑量乙醇及時間作用下行為學的改變；采用免疫組織化學技術檢測不同劑量乙醇作用下大鼠脊髓和下丘腦神經(jīng)細胞中P物質(zhì)的表達，通過掃描電子顯微鏡觀察神經(jīng)細胞的形態(tài)學變化。 結果 乙醇灌胃后0～2 h大鼠舔足次數(shù)有不同程度的變化，組間比較差異有統(tǒng)計學意義（Plt;0.05），灌胃2 h大鼠下丘腦和脊髓P物質(zhì)表達程度與乙醇劑量有相關關系，掃描電子顯微鏡下各組大鼠的神經(jīng)細胞形態(tài)學變化顯著。 結論 急性乙醇中毒可引起大鼠對疼痛反應的變化，其程度與乙醇劑量和作用時間有關，大鼠下丘腦和脊髓神經(jīng)細胞中P物質(zhì)的表達強度與乙醇劑量和作用時間有關。【Abstract】 Objective To observe the expression of substance P(SP)in the hypothalamus and spinal cord nerve cells of rats with different concentrations of ethanol, and to observe the morphological changes of nerve cells by scanning electron microscopic(SEM) for elucidating the mechanism of ethological changes effected with ethanol. Methods Ethological changes were detected through the formalin test; SP expressions in the hypothalamus and the spinal cord were evaluated with immunohistochemistry technology, and the morphological changes of nerve cells were observed by SEM. Results The frequency of licking foot changed when the rats were gavaged with different concentrations of ethanol among zero to two hours, the difference between two groups was statistical signifcant (Plt;0.05). The expression level of SP and the morphological changes of nerve cells in hypothalamus and spinal cord had relationship with the ethanol concentration. Conclusions Acute alcoholism could cause pain dysfunction in rats. The frequency of licking foot of rats is correlated to the role of the time closely. The expression intensity of SP in the hypothalamus and the spinal cord nerve cells are correlated to the concentration of ethanol closely.