Cerebrospinal fluid (CSF) is a clear, colorless fluid that bathes the central nervous system and is essential for brain homeostasis. CSF flows through interconnected ventricles which are lined by ependymal cells that generate a directional flow upon beating of their motile cilia. Defects in motile cilia can lead to a variety of neurological conditions like hydrocephalus, which is characterized by an accumulation of CSF in the brain. Nevertheless, the function of motile cilia-mediated fluid flow and its impact on brain development and physiology is still poorly understood. To address these questions, we analyzed mutant zebrafish larvae with paralyzed cilia and found that loss of ciliary motility did not change progenitor proliferation, overall brain morphology, or spontaneous neural activity. Instead, our neural data showed altered neuronal responses to photic stimulation, especially in the optic tectum and hindbrain, and randomization of brain asymmetry. We next investigated astroglia activity, given that astroglia contact CSF at the ventricular walls and are necessary for regulating neuronal activity. Our analyses revealed a significant reduction in both spontaneous and light-evoked astroglial activity. Our findings point towards a novel role of motile cilia-mediated flow in modulating neural and astroglial networks and offers a new perspective on the role of motile cilia in brain development and physiology