Bovine central nervous system development

Abstract

Central nervous system (CNS) development researches are extremely important to the most common congenital disorders and organogenesis comprehension. However, few studies show the entire developmental process during the critical period. Present research can provide data to new researches related to normal development and abnormalities and changes that occur along the CNS organogenesis, especially nowadays with the need for preliminary studies in animal models, which could be used for experimental research on the influence of viruses, such as the influence of Zika virus on the development of the neural system and its correlation with microcephaly in human newborns. Then, present study describes CNS organogenesis in cattle according to microscopic and macroscopic aspects, identifying structures and correlating to gestational period. Fourteen embryos and nine bovine fetuses at different ages were collected and analyzed. All individuals were measured in order to detect the gestational period. Bovine embryo at 17 days age has its neural tube, cranial neuropore, caudal neuropore and somites developed. After 24 days of development, were observed in cranial part of neural tube five encephalic vesicles denominated: telencephalon, diencephalon, mesencephalon, metencephalon and myelencephalon. In addition, the caudal part of neural tube was identified with the primitive spinal cord. The primordial CNS differentiation occurred from 90 to 110 days. The five encephalic vesicles, primordial spinal cord and the cavities: third ventricule, mesencephalic aqueduct, fourth ventricle and central canal in spinal cord were observed. With 90 days, the main structures were identified: (1) cerebral hemispheres, corpus callosum and fornix, of the telencephalon; (2) interthalamic adhesion, thalamus, hypothalamus and epythalamus (glandula pinealis), of the diencephalon; (3) cerebral peduncles and quadruplets bodies, of the mesencephalon; (4) pons and cerebellum, of the metencephalon; (5) medulla oblongata or bulb, of the myelencephalon; and (6) spinal cord, of the primitive spinal cord. After 110 days of gestation, the five encephalic vesicles and its structures were completely developed. It was noted the presence of the spinal cord with the cervicothoracic and lumbossacral intumescences. In summary, the results describes the formation of the neural tube from the neural plate of the ectoderm, the encephalic vesicles derived from the neural tube and subsequent structural and cavities subdivisions, thus representing the complete embryology of the central nervous system.

Morphological Characterization of the Developing Greater Cane Rat (<b><i>Thryonomys swinderianus</i></b>) Brain

“…Further differentiation of the primary brain vesicles to secondary brain vesicles was noted at GD60 in the GCR which marked the beginning of the second trimester. This is the consistent developmental trajectory reported in domestic mammals [30, 31].…”

Central nervous system development in rabbits (Oryctolagus cuniculus L. 1758)

“…In addition, we compared the chronological development of the central nervous system between humans and other long‐gestation animals. The time of primitive streak appearance was highly similar between alpacas, bovids, and humans (Ferreira et al, 2018; Greenstein & Foley, 1958; Montelli et al, 2019). Moreover, the development of the three primary brain vesicles was very similar between humans and horses.…”

“…We next compared the features of the normal development of the central nervous system between rabbits and humans and determined the stages of development in rabbits corresponding to those in humans (Table 2). We believe that this knowledge can aid research on diseases originating from the failure of embryonic neural tube closure including neural tube defects, such as anencephaly and spina bifida (Juriloff & Harris, 2018), and may also be applied in molecular studies, such as whole‐mount in situ hybridization (Ferreira et al, 2018; Kawamura & Matsumoto, 2018). Furthermore, such techniques based on the knowledge of the central nervous system organogenesis may help discover the genes or proteins involved in neurological pathologies affecting humans as well as explore the underlying signaling pathways and physiological mechanisms of hypoxic–ischemic encephalopathy, prenatal brain infections, and cerebral palsy (Saadani‐Makki et al, 2008).…”

“…The embryological phases of central nervous system development in humans have already been described (Menu, 2009; O'Rahilly & Müller, 2010; Shiraishi et al, 2015; Ten Donkelaar, Yamada, Shiota, & Van Der Vliet, 2014). These descriptions are also available for laboratory animals, such as mice (Chen et al, 2017; Chen et al, 2017; Ybot‐Gonzalez et al, 2007), rats (Alicelebić, Mornjaković, & Kundurović, 2004; Altman & Bayer, 1985; Bâ & Seri, 1993; Dziegielewska, Ek, Habgood, & Saunders, 2001; Favaron, Rodrigues, Oliveira, Biasi, & Miglino, 2012), and guinea pigs (Silva et al, 2016), as well as for livestock (Ferreira et al, 2018; Franciolli et al, 2011; Greenstein & Foley, 1958; Rigoglio et al, 2017) and other domestic animals (Knospe, 2002; Marin‐Padilla, 1971).…”

Craniosquise with Meningocelis in Newborn Calf

“…The embryological origin of the central nervous system is from the neural plate of the ectoderm. While the neural tube is observable in embryos from the 17 th day, complete organogenesis is observed after 110 days [3]. Susceptibility to genetic or external factors varies with the stage of development and decreases with increased fetal age [5].…”