Development of oxidative metabolism in the non-innervated optic lobe of the chick

Summary Early removal of the optic cup of the chick embryo prevents innervation of the contralateral optic lobe. This reduces the rate of development of citrate synthetase. The posthatch increase of the level of this enzyme related to oxidative metabolism is not impaired by denervation of the chick optic lobe.     

The localization of acetylcholinesterase in the optic lobe in the developing chick embryo

Summary The localization of acetylcholinesterase (AChE) in the optic lobe in the developing chick embryo was studied histochemically and biochemically. The histochemical reaction of AChE increased remarkably between stage 42 and 44 especially in the neuropile. The increase of the biochemical activity of the AChE in the synaptic membrane fraction occurred at a later stage than that in the microsomal fraction. These findings can be interpreted as the result of axonal transport of the enzyme from the synthetic to the synaptic site.Acknowledgments. The authors wish to thank Prof. Yasuharu Kuwahara, Cataract Research Institute, for the use of his cryostat and other laboratory facilities, Dr. Koji Kami, Department of Anatomy, Keio University School of Medicine, for his valuable advice regarding histochemistry.     

Nerve endings isolated from chick embryonic optic tectum. 2. Developmental aspects of synaptosomal membrane

Summary Fractions enriched in nerve endings (synaptosomes) have been isolated from chick embryonic optic tectum during development. After osmotic shock, these fractions appeared to be enriched in membranes which during development acquire typical features of mature synaptosomal membranes.     

New histochemical contributions to the study of corticotropic cells in the adenohypophysis of the chick enbryo.]

Comparative analysis of results obtained after subsequent treatments of chick embryo adenohypophysis by anti-ACTH 17-39 Is, PAS and Bodian method demonstrates that ACTH cells are PAS positive, Bodian negative and are located in the cephalic lobe. With the histochemical fluorescence method of Falck, the cells marked by anti-ACTH 17-39 Is exhibit an induced fluorescence, after L-DOPA injection. However, after treatment by metopirone, numerous cells of the caudal part of the adenohypophysis take up L-DOPA but they are not corticotrophs.     

Nerve endings isolated from chick embryonic optic tectum. 1. Developmental aspects of intact synaptosomes

Summary Fractions enriched in nerve endings (synaptosomes) have been isolated from optic tectum of chick embryos at 16 and 18 days of incubation and of chicks immediately after hatching. Morphological aspects of nerve endings have been examined with special regard to the appearance of synaptic thickenings and synaptic vesicles.     

Acetylcholinesterase decrease in the optic lobe after unilateral eye deprivation

Unilateral eye enucleation in a teleost and a turtle results in progressive AChE decrease in the optic lobe controlateral to the extirpated eye. The final difference reaches 15% in teleost and more than 20% in turtle. No drastic differences in localization, but a rearrangement of histochemical pattern, due to the degeneration of retinal fibres, is noticed.     

Acetylcholinesterase decrease in the optic lobe after unilateral eye deprivation

Summary Unilateral eye enucleation in a teleost and a turtle results in progressive AChE decrease in the optic lobe controlateral to the extirpated eye. The final difference reaches 15% in teleost and more than 20% in turtle. No drastic differences in localization, but a rearrangement of histochemical pattern, due to the degeneration of retinal fibres, is noticed.     

La glycolyse anaérobie au niveau des lobes optiques isolés de l'embryon de poulet

Summary A series ofin vitro experiments have been made on lactic acid production in anaerobiosis in the developing optic lobes (mesencephalon) of the chick embryo. The rate of anaerobic glycolysis is relatively important during multiplication of the neuroblasts; but, during the differentiation of the neuroblasts into mature neurons, the anaerobic processes are lower than the phosphorylation and oxidation mechanisms essential for the growth of nerve expansions and onset of functional activity.     

Changes in molecular species of pepsinogens in the development of the chick.

The potential peptic activity of the chick forestomach increases rapidly at the time of hatching. Together with this, the electrophoretic pattern of the pepsinogens shifts to the adult type. These changes take place even under the complete starvation of a newly hatch chick.     

Intrinsic forces alone are sufficient to cause closure of the neural tube in the chick

An isolated neural plate or a postnodal piece of early chick embryos, when cultured under appropriate experimental conditions, can undergo morphogenetic movements and form tubular structures closely resembling neural tubes of early chick embryos.     

Intrinsic forces alone are sufficient to cause closure of the neural tube in the chick

Summary An isolated neural plate or a postnodal piece of early chick embryos, when cultured under appropriate experimental conditions, can undergo morphogenetic movements and form tubular structures closely resembling neural tubes of early chick embryos.This work was supported by grants from the NIH (NS 23200 and NS 21730) and the Busch Fund of Rutgers University.     

N-cadherin detected in the membrane fraction of lens fiber cells

N-cadherin was identified as a glycoprotein present in the fiber cell membranes of frog, chick, bovine, rabbit and human lenses. The molecular size of N-cadherin varies with the species. Homogenization of the chick lens in the presence of Ca2+ resulted in a decrease in the concentration of N-cadherin. This suggests that the lens contains a Ca2(+)-activated protease which can act on N-cadherin.     

Mast cells are present during angiogenesis in the chick extraembryonic vascular system

The extraembryonic vascular membranes of 3-day-18-day chick embryos were examined for the presence of mast cells. As early as 3.5 days mast cells were found on the area vasculosa. It is suggested that these cells have a role in angiogenesis of the chick extraembryonic vascular system.     

N-cadherin detected in the membrane fraction of lens fiber cells

Summary N-cadherin was identified as a glycoprotein present in the fiber cell membranes of frog, chick, bovine, rabbit and human lenses. The molecular size of N-cadherin varies with the species. Homogenization of the chick lens in the presence of Ca²⁺ resulted in a decrease in the concentration of N-cadherin. This suggests that the lens contains a Ca²⁺-activated protease which can act on N-cadherin.     

Mast cells are present during angiogenesis in the chick extraembryonic vascular system

Summary The extraembryonic vascular membranes of 3-day-18-day chick embryos were examined for the presence of mast cells. As early as 3.5 ddays mast cells were found on the area vasculosa. It is suggested that these cells have a role in angiogenesis of the chick extraembryonic vascular system.The work is supported by The Wellcome Trust.     

Distribution of type A and B monamine oxidase activities in the central nervous system of rat and chick.

The distribution of type A and B monamine oxidase (MAO) activities in the central nervous system (CNS) of rat and chick was investigated using 5-hydroxytryptamine and beta-phenylethylamine as specific substrates. The distribution of type A MAO was similar to that of type B MAO in rat CNS, but quite different in chick CNS. This may be ascribed to the difference in animal species. The major part of MAO activity in the spinal cord was found to be type A.     

Polypeptides of the lens fibre cell intracellular matrix

Summary The cytoskeletal proteins of the vertebrate lens fibre cell comprise polypeptides ranging in mol.wt from 43,000 to 250,000 daltons. The main intermediate filament polypeptide of the pickerel, Northern frog, chick, bovine, and human lens has a mol.wt of 54,000 daltons. Peptide analysis revealed that the chick 54,000 dalton protein was more similar to the bovine protein than to the pickerel protein.Supported by grants EY 01417 (H. Maisel) and HD-06390 (J.C. Brown, University of Virginia, Charlottesville) from the National Institutes of Health, U.S.P.H.S.     

Innervation of the ovarian interstitial cell of the chick embryo.

Electron microscopic examination of the developing ovary of 15-20-day chick embryos revealed that the interstital cells well innervated. Nerve fibres and nerve endings were observed in close contact with steroid-producing cells.     

Biosynthesis of ascorbic acid in chick embryos

Summary Biosynthesis of ascorbic acid was found in the kidneys (mesonephros and metanephros) of the chick embryo as well as in the yolk sac membrane. The activity of L-gulonolactone oxidase in the yolk sac membrane suggested that it was the major source of ascorbic acid in the chick embryo.I am grateful to Dr R. Jenness (Univ. of Minnesota) for the generous gift of L-gulonolactone and to Dr B. Sanders (Univ. of Texas) for the chick embryo samples     

Innervation of the ovarian interstitial cell of the chick embryo

Summary Electron microscopic examination of the developing ovary of 15–20-day chick embryos revealed that the interstitial cells were well innervated. Nerve fibres and nerve endings were observed in close contact with steroid-producing cells.