Saurabh neuroscience. final
- 1. DEVLOPMENT OF BRAIN AND IT'S CONGENITAL ANOMALIES NEUROSCIENCE GUIDED BY :- DR.S.D.TRIPATHI.SIR SUBMITTED BY:-MR.SAURABH ASHOKRAO JADHAV
- 2. INTRODUCTION • Neural development refers to the processes that generate, shape, and reshape the NERVOUS SYSTEM of animals, from the earliest stages of Embryogenesis to Adulthood. • It is NeuroEctodermal in Origin • Brain is develop from anterior end of neural tube
- 4. FORMATION OF NEURAL TUBE
- 5. Left lateral views and sections through the developing brain. A, The three primary brain vesicles. B, Development of telencephalon and diencephalon. C, Development of the metencephalon and myelencephalon
- 7. A-Midline longitudinal section through the fore-brain showing the medial wall of the right cerebral hemisphere and the right thalamus and hypothalamus B-Cross-section through the fore-brain at the level indicated, Xshowing the lateral ventricles, the hippocampal lobes, the third ventricle and the choroid plexus DEVELOPMENT OF PROSENCEPHALON
- 8. A- Midline longitudinal section through the fore-brain at a later stage B- Cross-section through the fore-brain at the level indicated, X. C- Cross-section through the fore-brain at the level indicated, Y.
- 9. A-Midline longitudinal section through the fore-brain in the early foetal period showing the relationships of the developing brain structures. B-Cross-section at the level indicated, X.
- 11. Development of the basal and alar plates in the mesencephalon. Section through the mesencephalon at an early stage of development, A, and at a later stage of development, B, showing the alar and basal plates, the wide neural canal and migration of cells from the alar plates (arrows). C, Section through the mesencephalon showing the reduced size of the mesencephalic aqueduct and the development of motor and sensory nuclei from the basal and alar plates. The crura cerebri are also shown. Sections are at the levels indicated.
- 12. DEVELOPMENT OF RHOMBENCEPHALON A-Dorsal views and cross-sections at the levels indicated through the myelencephalon and B- the developing cerebellum and pons
- 13. Dorsal view and longitudinal section of the developing cerebellum showing the commencement of surface folding
- 14. Left lateral view and longitudinal section of the developing cerebellum showing marked folding of the surface, the formation of folia.
- 16. A CONGENITAL MALFORMATION IN CALVES; THERE IS A SMALL OPENING ON THE SURFACE OF THE CALVARIA; THE HOLE CONNECTS WITH A DEFORMED DIENCEPHALON WHICH MAY DISCHARGE CEREBROSPINAL FLUID CONGENITAL ANOMALIES OF BRAIN
- 17. HYDROCEPHALUS, an increase in volume of the CSF, can appear similar to hydranencephaly, but in hydrocephalus the ventricles retain a complete ependymal lining. Clinical signs can vary from mild to severe and include seizures, lethargy, or other forebrain abnormalities. There may be extensive expansion of the lateral ventricles in the frontal lobes. Hydrocephalus is seen sporadically in all large animals, although it is relatively common in calves, in which inheritance and vitamin A deficiency have been implicated. Holoprosencephaly is a disorder caused by the failure of the prosencephalon (the embryonic forebrain) to sufficiently divide into the double lobes of the cerebral hemispheres. ... Lobar, in which there is considerable evidence of separate brain hemispheres, is the least severe form.
- 18. Cerebellar hypoplasia is most frequently found in kittens and calves. The most common cause is prenatal or perinatal viral infections. CEREBELLAR HYPOPLASIA Cerebellar hypoplasia (fig. describes a situation where an insufficiency of neurons causes hypoplasia of the granular layer of the cerebellum. In severe cases, the Purkinje neurons will also be destroyed. The condition is most frequently found in kittens and calves, most commonly caused by prenatal or perinatal viral infections. The specific viruses are the feline panleukopaenia virus and the bovine virus diarrhoea (BVD) virus. CEREBELLAR ABIOTROPHY Cerebellar abiotrophy is characterized by the degeneration of the Purkinje cells in the already formed cerebellar cortex. It occurs postnatally or, occasionally, prenatally and has been observed in many domestic species. The primary defect that causes the degeneration is not known.
- 19. ARNOLD-CHIARI MALFORMATION Arnold-Chiari malformation is a condition characterized by caudal displacement and herniation of cerebellar structures through the foramen magnum into the cranial cervical vertebral canal. Arnold- Chiari malformation is often accompanied by spina bifida, meningomyelocoele, and hydrocephalus.
- 20. EXENCEPHALY Failure in the closure of the rostral neuropore, resulting in abnormal fore-brain development and interference with fusion of the bones of the cranium, gives rise to the condition referred to as exencephaly.When the cranial defect is small, the meninges can herniate and the anomaly is referred to as cranial meningocoele. A large cranial defect, which allows the meninges and part of the brain to herniate, is referred to as encephalocoele. MICROCEPHALY Microcephaly, an abnormally small brain, has been reported in calves, lambs, and piglets. Since the size of the cranium depends on the development of the brain, the cranial vault is considerably smaller than normal. External features of microcephaly include a narrow and flattened frontal area of the cranium. Cranial bones appear thicker than normal. The cause of the condition may be genetic or a prenatal insult such as an infection or exposure to a teratogen.
- 21. HYDRANENCEPHALY In hydranencephaly, the cerebral hemispheres are replaced by two fluid-filled sacs. The brain stem is usually not affected, but some degree of cerebellar hypoplasia may be observed. In domestic animals this condition is most commonly caused by an in utero viral infection (blue tongue virus in ruminants and panleukopaenia in cats) or, more rarely, by an interruption of the blood supply to the telencephalon.
- 22. DICEPHALIC (˘MUITIPLE MALFORMATION) Two-headed animals (called bicephalic or dicephalic) they are monozygotic twin embryos.
- 23. MENINGOCELE AND LIPOMENINGOCELE Meningocele typically causes mild problems with a sac of fluid present at the gap in the spine. Myelomeningocele, also known as open spina bifida, is the most severe form. Associated problems include poor ability to walk, problems with bladder or bowel control, hydrocephalus, a tethered spinal cord, and latex allergy.
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