Effects of Cisplatin on the Chick Embryo — A Model for the Analysis of Prenatal Toxicity
Sam Kacew in Drug Toxicity and Metabolism in Pediatrics, 1990
Malformations of the nervous system are among the most frequent effects found in teratological experiments. This is probably due to the fact that growth and development of this system is a continuous process occurring during the whole embryonic, fetal, and early postnatal periods. The morphological characteristics and mechanisms of development of the nervous system have been discussed in great detail in numerous reviews and books.27,28 Only the aspects of this process which are relevant to prenatal brain lesions will be covered. The first steps in the formation of the central nervous system occur very early in development. The neural plate becomes a neural groove and then both lateral lips of the groove contact each other dorsally so that the groove becomes transformed into a tube, the neural tube. This process of closure of the groove can be affected by genetic or environmental factors. Partial or total failure as well as delay in its completion might give rise to any one of a group of malformations known under the generic name of disraphiae (spina bifida, anencephalus, encephalocele, etc.).
Skeletal Embryology and Limb Growth
Manoj Ramachandran, Tom Nunn in Basic Orthopaedic Sciences, 2018
The ectoderm forms the neural tube by a process called neurulation. In the midline, ectodermal cells become elongated, causing a relative thickening in that region (the neural plate). The two edges of the neural plate thicken to form the neural groove and neural folds. The neural tube forms by the fusion of the edges of these folds, which begins near the anterior end of the embryo and proceeds in anterior and posterior directions. The neural groove closes by the third week, except at its ends (the anterior and posterior neuropores), which normally close by the end of the fourth week. Failure of the anterior neuropore to close results in anencephaly, whilst neural tube defects (NTDs) are most commonly thought to arise from a failure of the posterior neuropore to close.
Embryology of the Spinal Cord, Peripheral Nerves, and Vertebrae
Bernard J. Dalens, Jean-Pierre Monnet, Yves Harmand in Pediatric Regional Anesthesia, 2019
In stage 9 (1.5- to 2-mm embryos, 19 to 20 d), the neural plate is curled (Figure 1.4). The embryonic disc elongates and the primitive streak and Hensen’s node appear to be carried caudad, since the cephalic area grows more rapidly. The embryo changes its shape, becoming first oval, then pear shaped. At this stage, the neural groove is in close contact with the notochord. Mesenchymatous cells of both sides of the notochord (paraxial mesoderm) show intense mitotic activity and differentiate as paired blocks of cells, the somites. This fundamental aspect of metamerism of the body does not occur in the paraxial mesoderm of the cephalic area.
Hearing loss and brain abnormalities due to pathogenic mutations in ADGRV1 gene: a case report
Published in Hearing, Balance and Communication, 2020
Flavio Faletra, Anna Morgan, Sara Ghiselli, Flora Maria Murru, Giorgia Girotto
ADGRV1 is a gene involved in Usher type 2 syndrome (MIM#: 605472; ORPHA: 231178), a rare disease characterised by sensorineural HL with or without vestibular problems, and retinitis pigmentosa (RP). Mutations in this gene are generally correlated with sensorineural hearing deficiencies at birth and later onset of progressive RP, this last one, a condition not already manifested in our patient, considering her young age. Interestingly, in mouse models, this gene is highly expressed in the neural groove and the neuroepithelium [2]. Furthermore, literature data showed that mutations in ADGRV1 have also been associated with different brain abnormalities (patient IT_FLO_020 in [3,4] and different neuropsychiatric manifestations/disorders including epilepsy and/intellectual disability [3,5] thus might explain the presence of the brain abnormalities identified in our patient.
Related Knowledge Centers
- Ectoderm
- Mesoderm
- Nervous System
- Neural Plate
- Neural Tube
- Primitive Streak
- Embryo
- Ganglion
- Neural Fold
- Neurenteric Canal