关键词: 喜马拉雅早獭, 大脑皮质, 锥体细胞, 树突棘, 突触, 棘器

Abstract: This paper reports 24 unhibernation Marmota himatayan which were reared in temprature 5-20℃ room of altitude 3300m．The authors divide it into three age groups (juvenile，adult，old)．Some physiologieal parameters，the blood gaseous analysis，the variation of neurons and spine apparatus as well as the ultastructure of the cerebral cortex were determined respecively．The results are as follows：
1．The comprison between the adult and juvenile presented the decrease of BrW／BW ，but haemoglobin，haematocrit,O₂ utilized rate were increase in the adult (see table 1, 3)．
2．The comparison between the old and adult presented also the decrease of BrW/ BW and O₂ utilized rate，but Hb，Hct were still increase in the old (see table 1, 3)．
A significant neuronal loss in cerebral cortex were observed and the mean values of the pyramidal ceils and the spine apparatus were 16.08±2.9/200um² and 9.14±1.54 in the old．Compared the old to the adult，the decrease of the pyramidal cells and the spine apparatus in the old were 29.8 %(P< 0.01) and 33.8 %(P< 0.01)．The decrease of rough surface emloplasmic reticulum，free ribosome，synape vesicles，and the increase of the lipofuscin in pyramidal cells in the old were observed too．

Key words: Marmota himalayana, Cerebral cortex, Pyramidal cell, Dendritic spine, Synapse, Spine apparatus