Ultrastructural study of the lateral ventricle choroid plexus in experimental hydrocephalus in Wistar rats

Abstract

-Hydrocephalus is one of the most frequent and complex neurological diseases characterized by the abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain, due to an altered CSF dynamics. To detect possible ultrastructural alterations of the lateral ventricles choroid plexus (responsible for the CSF production), rats seven days after birth were submitted to an intracisternal injection of 20% kaolim (hydrated aluminum silicate) for the hydrocephalus induction. Twenty-eight or 35 days after injection, injected animals and respective controls were processed for observation under a transmission electron microscopy. Alterations found: presence of concentric cell membrane fragments, larger number of primary and secondary lysossomes, vacuoles, and cytoplasmic vesicles, and an enlargement of the intercellular space and between the basolateral interdigitation of the choroid epithelium. The alterations observed are probably associated to an increase of the ventricular pressure, inducing morpho-functional effects on the choroid plexus integrity.KEY WORDS: hydrocephalus, choroid plexus, ultrastructural study, rat. Estudo ultraestrutural dos plexos corióides dos ventrículos laterais de ratos Wistar submetidos a hidrocefalia experimentalRESUMO -A hidrocefalia é uma das mais freqüentes e complexas doenças neurológicas caracterizada pelo acúmulo de líquido cefalorraquidiano (LCR) no interior dos ventrículos cerebrais e conseqüente alteração na dinâmica liquórica. Para detectar as possíveis alterações ultra-estruturais nos plexos corióides dos ventrículos laterais (responsáveis pela produção do LCR), ratos sete dias após o nascimento, foram submetidos à indução de hidrocefalia pela injeção intracisternal de caulim a 20%. Após 28 e 35 dias da injeção, estes animais e seus respectivos controles foram processados para observação em um microscópio eletrôni-co de transmissão. Alterações observadas: presença de membranas concêntricas, maior número de lisossomos primários e secundários, vacúolos e vesículas citoplasmáticas, aumento do espaço intercelular e entre as interdigitações basolaterais das células do epitélio corióideo. As alterações observadas possivelmente estão associadas ao aumento da pressão nos ventrículos, induzindo efeitos morfo-funcionais na integridade dos plexos corióides. PALAVRAS-CHAVE: hidrocefalia, plexos corióides, estudo ultra-estrutural, rato.

Aquaporins: relevance to cerebrospinal fluid physiology and therapeutic potential in hydrocephalus

“…There was also gold-labelling of AQP1 along the basolateral membrane. The changes in AQP1 localisation were associated with other ultrastructural changes (Figure 5) reported by other authors in relation to the choroid plexus in hydrocephalus [18]. Such ultrastructural changes include a reduction in the number of microvilli which become shorter and swollen, the appearance in the cytoplasm of primary and secondary endosomes and lysosomes within the cytoplasm as well as the appearance of intercellular clefts.…”

“…Despite the appearance of the latter, tight junctions at the apical membrane remained intact. Apoptosis was not present in our study or those of others [18]. The association of these changes, particularly those of the microvilli, with the observation that AQP1 localisation is altered raises the question of whether the changes in AQP1 localisation are a reflection of ultrastructural alterations or whether they reflect a compensatory mechanism for hydrocephalus, or both.…”

Pathophysiology of the choroid plexus in brain diseases

“…Morphological-functional effects of hydrocephalus on the CP tissue include atrophy of epithelium, reduction in number, as well as shortening and swelling of microvilli, sclerotic stroma, dilatation of intracellular spaces and of basolateral interdigitations (Shuangshoti et al 1965;Madhavi and Jacob 1995;Owler et al 2010). Intercellular junctions seem to be preserved (Tirapelli et al 2007). The changes are accompanied by infestation and the increase of various types of immune cells (Go et al 1976;Lu et al 1996;Solár et al 2020a).…”

Efeitos de um derivado polifenólico da <i>Camellia sinensis </i>na hidrocefalia experimental induzida em ratos Wistar

“…As alterações do plexo coróide são mais brandas que do epêndima, com distorções das vilosidades, achatamento e vacuolização das células, com formação de inclusões intracelulares e alargamento dos espaços intercelulares (DEL BIGIO et al, 1985;KIEFER et al, 1998;DEL BIGIO et al, 2002;TIRAPELLI et al, 2007).…”