碩士 / 國立臺灣大學 / 解剖學暨細胞生物學研究所 / 93 / Hydrocephalus is known to affect learning, which is generally believed to be an important function of the hippocampus. To investigate the anatomic substrate of this hydrocephalus-induced deficiency, we took advantage of a kaolin-induced rat obstructive hydrocephalus model and studied its effect on hippocampus. Hippocampus was studied 1 (acute) and 4 week (chronic) following kaolin injection into cisterna magna. The intracranial pressure of animals increased significantly in acute, and persisted to chronic cases. Intracranial pressure increased as the ventricules gained in sizes. Thinning of white matter was more dramatic than gray matter as the ventriculomegaly advanced. Hippocampus appeared to be compressed more obviously in the horizontal direction based on the alteration of its shape. In both CA3 and CA1 areas, microglial and astrocytic reactions was inducted in both acute and chronic animals. The density of NOS-immunoreactive neurons in hippocampus remained low following hydrocephalus. As to the dendritic arbors of the CA3 pyramidal neurons, intracellular dye injection revealed that the total dendritic length, which was caused by a specific decrease of apical dendrites, of acute animals was significantly decreased. The density of dendritic spines on all the dendrites of this neuron both acute and chronic animals was significantly decreased. In conclusion, in addition to reactive glial responses, obstructive hydrocephalus caused the remodeling of the dendritic arbors of CA3 pyramidal neurons. The alteration of receiving structures implies changes of hippocampal input as well as output. The phenomena we observed are likely to underlie the impairment of learning reported of hydrocephalic animals.
| Identifer | oai:union.ndltd.org:TW/093NTU01391005 |
| Date | January 2005 |
| Creators | Peng, Hsiao-Yu, 彭筱伃 |
| Contributors | 曾國藩 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 59 |
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