Background
Cerebrospinal fluid (CSF) is mainly produced by the choroid plexuses within the ventricles of the brain. Hydrocephalus occurs when the normal flow of CSF is obstructed and fluid accumulates. The CSF circulates in a regular manner from the formation of the neural tube and enables it to carry chemical information. From the lateral ventricles CSF passes into the third ventricle and then moves on to the fourth ventricle. CSF leaves the ventricular system and enters the subarachnoid spaces. Ultimately CSF drains out of the subarachnoid space into the sagittal sinus via the arachnoid villi. CSF thus flows through the ventricular system passing over all regions of germinal activity. In previous studies on a rat model of hydrocephalus, the hydrocephalic Texas (HTx) rat, we showed that CSF has a potential role in the development of the cerebral cortex. In this study chick embryos were used to show the importance of CSF on brain development