Genetical analysis ofvisual system disorganizer (vid), a new gene involved in normal development of eye and optic lobe of the brain inDrosophila melanogaster

Genetica ◽  
1997 ◽  
Vol 99 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Mohammed Rachidi ◽  
Carmela Lopes ◽  
Jean-Claude Benichou
Keyword(s):  
Normal Development ◽  
Optic Lobe ◽  
Genetical Analysis ◽  
New Gene ◽  
The Brain

scholarly journals Survival of photoreceptor neurons in the compound eye of Drosophila depends on connections with the optic ganglia

Development ◽  
1992 ◽  
Vol 114 (2) ◽  
pp. 355-366 ◽  
Author(s):  
A.R. Campos ◽  
K.F. Fischbach ◽  
H. Steller
Keyword(s):  
Trophic Interactions ◽  
Compound Eye ◽  
Normal Development ◽  
Optic Lobe ◽  
Photoreceptor Cells ◽  
Optic Lobes ◽  
Genetic Mosaic ◽  
Retinal Innervation ◽  
Photoreceptor Neurons ◽  
The Brain

The importance of retinal innervation for the normal development of the optic ganglia in Drosophila is well documented. However, little is known about retrograde effects of the optic lobe on the adult photoreceptor cells (R-cells). We addressed this question by examining the survival of R-cells in mutant flies where R-cells do not connect to the brain. Although imaginal R-cells develop normally in the absence of connections to the optic lobes, we find that their continued survival requires these connections. Genetic mosaic studies with the disconnected (disco) mutation demonstrate that survival of R-cells does not depend on the genotype of the eye, but is correlated with the presence of connections to the optic ganglia. These results suggest the existence of retrograde interactions in the Drosophila visual system reminiscent of trophic interactions found in vertebrates.

A study of the properties, morphogenetic potencies and prospective fate of outer and inner layers of ectodermal and chordamesodermal regions during gastrulation, in various Anuran amphibians

Development ◽  
1983 ◽  
Vol 75 (1) ◽  
pp. 67-86
Author(s):  
T. A. Dettlaff
Keyword(s):  
Outer Layer ◽  
Normal Development ◽  
Neural Plate ◽  
Ependymal Cells ◽  
Epithelial Layer ◽  
Bombina Bombina ◽  
Cell Layers ◽  
The Brain ◽  
Early Gastrula

In both the ectodermal and the chordamesodermal regions of Anuran embryos, the outer layer of cells possesses epithelial properties and has the same restricted morphogenetic potencies. It is thus interchangeable between the regions, capable of epiboly and, when underlain by notochord material, of the formation of bottle-shaped cells as at the blastoporal groove, and invagination. When taken from the chordamesoderm region, this outer layer has no inducing effect on the ectoderm of the early gastrula. In normal development the outer layer of the neural plate takes an active part in forming the neural tube cavity. It gives rise to the neuroepithelial roof of the diencephalon and medulla oblongata and, when underlain by neuroblasts that develop from the inner cell layers, to ependymal cells of the brain wall. The outer layer of the notochord material is included in the epithelial layer underlying the roof of the gastrocoel - the hypochordal plate. The inner layers of these regions consist of loosely arranged cells and normally have no epithelial properties although, when taken from the ectoderm region, they may acquire such properties upon long-term contact with the environment. However they have wide morphogenetic potencies; the differences in these potencies between cells taken from the various presumptive regions being less than the differences between outer and inner cell layers in each region. Maps are provided which show the arrangement of presumptive rudiments in the ectoderm and chordamesoderm on sagittal sections through Bombina bombina embryos in early and late gastrulation.

Ultrastructure and synaptic relations in the optic lobe of the brain of Eledone and Octopus

1972 ◽  
Vol 39 (1-2) ◽  
pp. 115-123 ◽  
Author(s):  
Norman M. Case ◽  
E.G. Gray ◽  
J.Z. Young
Keyword(s):  
Optic Lobe ◽  
The Brain

scholarly journals Brain manganese and the balance between essential roles and neurotoxicity

2020 ◽  
Vol 295 (19) ◽  
pp. 6312-6329 ◽  
Author(s):  
Rekha C. Balachandran ◽  
Somshuvra Mukhopadhyay ◽  
Danielle McBride ◽  
Jennifer Veevers ◽  
Fiona E. Harrison ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Normal Development ◽  
The Body ◽  
Neurological Dysfunction ◽  
Cellular Transport ◽  
Brain Health ◽  
Biochemical Mechanisms ◽  
Molecular And Biochemical Mechanisms ◽  
Neuronal Physiology ◽  
The Brain

Manganese (Mn) is an essential micronutrient required for the normal development of many organs, including the brain. Although its roles as a cofactor in several enzymes and in maintaining optimal physiology are well-known, the overall biological functions of Mn are rather poorly understood. Alterations in body Mn status are associated with altered neuronal physiology and cognition in humans, and either overexposure or (more rarely) insufficiency can cause neurological dysfunction. The resultant balancing act can be viewed as a hormetic U-shaped relationship for biological Mn status and optimal brain health, with changes in the brain leading to physiological effects throughout the body and vice versa. This review discusses Mn homeostasis, biomarkers, molecular mechanisms of cellular transport, and neuropathological changes associated with disruptions of Mn homeostasis, especially in its excess, and identifies gaps in our understanding of the molecular and biochemical mechanisms underlying Mn homeostasis and neurotoxicity.

scholarly journals Biallelic variants in the small optic lobe calpain CAPN15 are associated with congenital eye anomalies, deafness and other neurodevelopmental deficits

2020 ◽  
Vol 29 (18) ◽  
pp. 3054-3063
Author(s):  
Congyao Zha ◽  
Carole A Farah ◽  
Richard J Holt ◽  
Fabiola Ceroni ◽  
Lama Al-Abdi ◽  
...  
Keyword(s):  
Optic Lobe ◽  
Critical Role ◽  
Genetic Diagnosis ◽  
Compound Heterozygous ◽  
Clinical Genetic ◽  
Eye Disorders ◽  
Neurodevelopmental Deficits ◽  
Independent Families ◽  
The Brain

Abstract Microphthalmia, coloboma and cataract are part of a spectrum of developmental eye disorders in humans affecting ~12 per 100 000 live births. Currently, variants in over 100 genes are known to underlie these conditions. However, at least 40% of affected individuals remain without a clinical genetic diagnosis, suggesting variants in additional genes may be responsible. Calpain 15 (CAPN15) is an intracellular cysteine protease belonging to the non-classical small optic lobe (SOL) family of calpains, an important class of developmental proteins, as yet uncharacterized in vertebrates. We identified five individuals with microphthalmia and/or coloboma from four independent families carrying homozygous or compound heterozygous predicted damaging variants in CAPN15. Several individuals had additional phenotypes including growth deficits, developmental delay and hearing loss. We generated Capn15 knockout mice that exhibited similar severe developmental eye defects, including anophthalmia, microphthalmia and cataract, and diminished growth. We demonstrate widespread Capn15 expression throughout the brain and central nervous system, strongest during early development, and decreasing postnatally. Together, these findings demonstrate a critical role of CAPN15 in vertebrate developmental eye disorders, and may signify a new developmental pathway.

Neuronal pathways of classical crustacean neurohormones in the central nervous system of the woodlouse, Oniscus asellus (L.)

1995 ◽  
Vol 347 (1320) ◽  
pp. 139-154 ◽  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Optic Lobe ◽  
Decapod Crustacean ◽  
Crustacean Hyperglycemic Hormone ◽  
Neurosecretory Pathways ◽  
Whole Mount ◽  
Hyperglycemic Hormone ◽  
The Central Nervous System ◽  
The Brain

Neuropeptide-immunoreactive neurons have been mapped by immunocytochemistry in whole-mount preparations and sections of the central nervous system of Oniscus asellus . We tested rabbit antisera against decapod crustacean hyperglycemic hormone (CHH), moult inhibiting hormone (MIH ), pigment dispersing hormone (PDH) and red pigment concentrating hormone (RPCH). four CHH- and three PDH-immunoreactive neurons localized in the superior median protocerebrum of the brain constitute neurosecretory pathways to the neurohaemal sinus gland. No immunoreactive structures have been detected with an antiserum against MIH of Carcinus maenus . Another, newly identified neurosecretory pathway is formed by a group of RPCH-immunoreactive neurons in the mandibular ganglion. These neurons project to the neurohaemal lateral cephalic nerve plexus, further PDH- and RPCH-immunoreactive neurons and fibres occur in the brain and the ventral nerve cord (VNC). Two groups of PDH-immunoreactive neurons supply brain and optic lobe neuropils, the bases of the ommatidia, and probably give rise to descending fibres innervating all VNC-neuropils. Two groups and five individuals of RPCH-immunoreactive neurons that innervate several brain neuropils or occur as ascending neurons in the VNC have been reconstructed. The CHH-immunoreactive neurons, and distinct types of PDH- and RPCH-immunoreactive neurons obviously belong to classical hormone-producing neurosecretory pathways. At least the CHH-immunoreactive cells seem to be part of an isopod homologue of the decapod X-organ. The existence of other PDH- and RPCH-immunoreactive interneurons suggests additional functions of these peptides as neurotransmitters or neuromodulators, which is in agreement with similar observations in the decapod central nervous system.

The chromatic and motor effects of neurotransmitter injection in intact and brain-lesioned Octopus

1983 ◽  
Vol 63 (2) ◽  
pp. 355-370 ◽  
Author(s):  
P. L. R. Andrews ◽  
J. B. Messenger ◽  
E. M. Tansey
Keyword(s):  
Control System ◽  
Optic Lobe ◽  
Brain Lesions ◽  
Octopus Vulgaris ◽  
Motor Effects ◽  
Sites Of Action ◽  
Differential Expansion ◽  
The Brain

Various neurotransmitters were injected into the blood supplying the brain of Octopus vulgaris and the effects, particularly on the chromatophores, were observed. l-glutamate, GABA, dopamine, noradrenaline and octopamine caused expansion of the chromatophores and darkening of the skin; ACh caused retraction of the chromatophores and paling; 5HT caused differential expansion and retraction: mottling. These responses, which are neurally mediated, were particularly well defined for ACh and 5HT and the effects of these drugs were studied in more detail. The paling effect of ACh was mimicked by nicotine but not muscarine and was partially antagonized by tubocurarine. The mottling induced by 5HT was transiently antagonized by methysergide maleate, as was ink-ejection and defaecation. Brain lesions to localize the sites of action of ACh and 5HT suggest that they act at the level of the sub-oesophageal lobes to control the chromatophores, but that 5 HT may act at the level of the optic lobe to control inking and defaecation. These results are related to the pharmacology and histochemistry of the cephalopod brain and to the organization of the chromatophore control system.

The Mongol: A New Explanation

1929 ◽  
Vol 75 (309) ◽  
pp. 261-262 ◽  
Author(s):  
R. M. Clark
Keyword(s):  
Normal Development ◽  
Human Foetus ◽  
Feeding Experiments ◽  
Cutting Out ◽  
Characteristic Features ◽  
General Physical ◽  
Hands And Feet ◽  
Heart Lesions ◽  
The Brain ◽  
Endocrine Disturbance

My view that mongolism is caused by fœtal hyperthyroidism ceasing at birth, is based on the theory that if the known actions of hyperthyroidism on the embryos of animals, as proved by feeding experiments and otherwise, were at work on the human fœtus, the characteristic features of the mongol would be produced. Fœtal hyperthyroidism could not fail to cause abnormal endocrine inter-reaction, and it has been said that in every mongol some endocrine disturbance can be demonstrated. The action hyperthyroidism has on frog embryos, including the cutting out of the later stages of normal development and growth, and the action thyroxin has in retarding cell division and embryonic development, would explain the general arrest of growth and development of the mongol, including that of the skull and the brain. The same actions would also account for the coincident congenital anomalies, e.g., congenital heart lesions, cleft palate, hypospadias, undescended and undeveloped testicles, primitive hands and feet, syndactyly of fingers and toes, atresia of anus, spina bifida, etc.; these are also manifestations of arrested development, and in favour of a common cause for the local and the general defects, are the facts that both are symmetrical, and that there is a parallelism between the amount of general physical defect, the number of anomalies, and the degree of amentia.

Ontogeny of the brain in oval squid Sepioteuthis lessoniana (Cephalopoda: Loliginidae) during the post-hatching phase

2013 ◽  
Vol 93 (6) ◽  
pp. 1663-1671 ◽  
Author(s):  
Shiori Kobayashi ◽  
Chitoshi Takayama ◽  
Yuzuru Ikeda
Keyword(s):  
Nervous System ◽  
Body Weight ◽  
Body Size ◽  
Embryonic Development ◽  
Frontal Lobe ◽  
Optic Lobe ◽  
Relative Volume ◽  
Mantle Length ◽  
Sepioteuthis Lessoniana ◽  
The Brain

Among invertebrates, cephalopods have one of the most well-organized nervous systems. However, with respect to the ontogeny of the nervous system, the post-embryonic development of the cephalopod brain has only been documented for a few species. Here, we investigated the development of the brain of captive oval squid Sepioteuthis lessoniana during the post-hatching phase. The central part of the brain of the oval squid is divided into four main regions, namely, the supraoesophageal, anterior suboesophageal, middle suboesophageal, and posterior suboesophageal masses, each consisting of several lobes. At various ages in juvenile squid, the total volume of the central part of the brain (except the optic lobe) is significantly correlated with its body size, indicated by mantle length and wet body weight. The vertical lobe, superior frontal lobe, and anterior subesophageal mass drastically increase in relative volume as the squid grows. In contrast, the middle suboesophageal mass and posterior suboesophageal mass do not increase in volume with increasing squid age and body size. The effects of these results have been discussed in relation to the onset of squid behaviours during post-hatching.

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