Embryopathoetiology of Congenital Hydrocephalus in Experimental Models: A Comparative Morphological Study in Two Different Models
We studied the morphological aspects of two different kinds of exerimental hydrocephalic model in rats. LEW/Jms rats were used as an inherited congenital hydrocephalic strain and 6-aminonicotinamide (6-AN, a niacinamide antimetabolite)-induced hydrocephalus was studied as an exogenous insult-induced hydrocephalus.
In LEW/Jms rats, aqueduct obstruction was observed on gestational day 17, prior to definite evidence of ventricular enlargement. The form of the aque-ductal obstruction was found to be simple stenosis, according to Russell’s classification. This finding suggested that aqueductal stenosis was the primary cause of hydrocephalus in the LEW/Jms hydrocephalic strain. This strain might be a model of human sex-linked hydrocephalus.
In 6-AN-induced hydrocephalic rats, dilatation of the whole ventricular system was observed. In this model, evidence of cerebral dysgenesis was suggested by bromodeoxyuridine (BUdR) immunostaining. However, the ventricular dilatation was resulted not only from cerebral dysgenesis, but also from increased intracranial pressure. This model was characteristic in that, in addition to the hydrocephalic state, various central nervous system malformations existed, such as cerebellar dysgenesis, absence of corpus callosum, and so on. These pathological findings suggested that 6-AN-induced hydrocephalus might be a model of human Dandy-Walker syndrome.
KeywordsCongenital hydrocephalus X-Linked Hydrocephalus LEW/Jms strain 6-Aminonicotinamide Dandy-Walker syndrome
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