Ajiboye Ebenezer O, Olopade Funmilayo Eniola, Femi-Akinlosotu Omowumi Moromoke, Shokunbi Matthew Temitayo
Department of Anatomy, Developmental Neurobiology and Forensic Anatomy Unit, University of Ibadan, Ibadan, Nigeria.
Anatomy Unit, Faculty of Basic Medical Sciences, Ajayi Crowther University, Oyo, Nigeria.
J West Afr Coll Surg. 2024 Oct-Dec;14(4):370-379. doi: 10.4103/jwas.jwas_118_23. Epub 2024 Jul 18.
The hippocampal alterations resulting from hydrocephalus are associated with various cognitive dysfunctions. Reduced learning and memory are early functional deficits that recover with time in experimental hydrocephalus. This study investigated the recovery processes of learning and memory loss in relation to the morphology of hippocampal pyramidal neurons and the degree of expansion of the ventricles.
Hydrocephalus was induced in adult mice by intracisternal injection of sterile kaolin while controls received sham operation. Neurobehavioral tests for memory and learning were conducted, after which the animals were sacrificed in batches: 7 (acute) and 28 (subacute) days postinduction. After sacrifice, mice were categorized into mild and moderate hydrocephalus, and their fixed brain samples were processed for hematoxylin, eosin, and Nissl stains.
In moderate acute hydrocephalus, the indices of learning and memory were reduced escape latency (67.20 ± 12.83 s), number of platform crossing (4.000 ± 1.658), duration in platform quadrant (4.000 ± 1.658), and percent of total investigation (44.857% ± 3.981%) but not in the subacute stage. Pyknotic indices (PI) were significantly higher in the cornu ammonis (CA)1 and 3 regions in all hydrocephalic groups than in controls. However, within groups, PI was significantly higher only in the CA1 of moderate acute (28.149% ± 1.875%) compared to moderate subacute hydrocephalic group (12.903% ± 3.23%).
Hydrocephalus caused cellular injury to the hippocampus associated with spatial learning and memory deficits. However, these functional deficits were partially reversed in moderate subacute hydrocephalus despite the persistence of the structural alterations in the CA1 and CA3 subregions.
脑积水导致的海马体改变与多种认知功能障碍相关。学习和记忆减退是实验性脑积水中早期出现的功能缺陷，且会随时间恢复。本研究调查了学习和记忆丧失的恢复过程与海马体锥体细胞形态及脑室扩张程度的关系。
通过脑池内注射无菌高岭土在成年小鼠中诱导脑积水，而对照组接受假手术。进行记忆和学习的神经行为测试，之后将动物分批处死：诱导后7天（急性期）和28天（亚急性期）。处死后，将小鼠分为轻度和中度脑积水组，并对其固定的脑样本进行苏木精、伊红和尼氏染色处理。
在中度急性脑积水中，学习和记忆指标包括逃避潜伏期缩短（67.20±12.83秒）、穿越平台次数减少（4.000±1.658次）、在平台象限的停留时间缩短（4.000±1.658秒）以及总探索时间百分比降低（44.857%±3.981%），但在亚急性期没有这些情况。所有脑积水组的海马角（CA）1和3区域的固缩指数（PI）均显著高于对照组。然而，在组内，与中度亚急性脑积水组（12.903%±3.23%）相比，中度急性脑积水组CA1区域的PI仅显著更高（28.149%±1.875%）。
脑积水导致海马体细胞损伤，与空间学习和记忆缺陷相关。然而，尽管CA1和CA3亚区域的结构改变持续存在，但在中度亚急性脑积水中这些功能缺陷部分得到了逆转。
