(A) Cone photoreceptor cells labelled by the Zpr-1 antibody in wild-type zebrafish and zebrafish groups treated with SiO₂-NPs. (B) Tyrosine hydroxylase expression in the posterior tuberculum (TP) (measured by immunohistochemistry) and in the brain (measured by western blotting). (C) The histopathology of the brain and retina in wild-type zebrafish and in the groups treated with SiO₂-NPs. ATN, anterior tuberal nucleus. Chor, commissura horizontalis. CP, central posterior thalamic nucleus. Cpost, commissural posterior. Ctec, commissural tecti. DIL, diffuse nucleus of the inferior lobe. DiV, diencephalic ventricle. DP, dorsal posterior thalamic nucleus. FR, fasciculus retroflexus. Hd, dorsal zone of periventricular hypothalamus. Hv, ventral zone of periventricular hypothalamus. LH, lateral hypothalamic nucleus. LR, lateral recess of diencephalic ventricle. PGI, lateral preglomerular nucleus. PGm, medial preglomerular nucleus. PGZ, periventricular gray zone of optic tectum. Pit, pituitary. PPd, periventricular pretectal nucleus, dorsal part. PPv, periventricular pretectal nucleus, verntal part. PTN, posterior tuberal nucleus. TeO, tectum opticum. TeV, tectum ventricle. TL, torus longitudinalis. TLa, torus lateralis. TPM, trcatus pretectomamillaris. TPp, periventricular nucleus of posterior tuberculum. VOT, ventrolateral optic tract.ONL, outer nuclear layer. INL, inner nuclear layer. APN, accessory pretectal mucleus. CC, crista cerebellaris. CCe, corpus cerebelli. Cgus, commissure of the secondary gustatory nuclei. DOT, dorsomedial optic tract. ECL, external cellular layer of olfactory bulb including mitral cell. EG, eminetia granularis. ENv, entopenduncular nucleus, vertral part. GC, griseum centrale. GL, glomerular layer of olfactory bulb. LCa, lobus caudalis cerebelli. LFB, lateral forebrain bundle. LLF, lateral longitudinal fascicle. LX, vagal lobe. MLF, medial longitudinal fascicle. NLV, nucleus lateralis valvulae. NMLF, nucleus of the medial longitudinal fascicle. NIV, trochlear nucleus. PC, posterior cerebellar tract. PM, magnocellular preoptic nucleus. PO, posterior pretectal nucleus. POF, primary olfactory fiber layer. PPa, periventricular pretectal nucleus, anterior part. PSm, magnocellular superficial pretectal nucleus. PSp, parvocellular superficial pretectal nucleus. RV, rhombencephalic ventricle. SGN, secondary gustatory ventricle. TelV, telencephalic ventricles. TSvl, ventrolateral nucleus of torus semicircularis. V, ventral telencephalic area. Vam, medial division of valvula cerebelli. VI, lateral nucleus of V. VL, ventrolateral thalamic mucleus. VM, ventromedial thalamic nucleus. Vv, ventral nucleus of V. IV, trochlear nerve. Cropped blots are used in the figure. Full-length blots are presented in Supplementary Figure S12. The images of zebrafish brain atlas in parts B and C are reproduced from Wullimann, M., Neuroanatomy of the Zebrafish Brain: A topological atlas, Birkhauser press, Basel (1996)³⁶, chapter 5 figure 153 and chapter 5 figure 26, respectively, with kind permission from Springer Science and Business Media.