Expression of en and wg in the embryonic head and brain of Drosophila indicates a refolded band of seven segment remnants

Development ◽  
1992 ◽  
Vol 116 (1) ◽  
pp. 111-125 ◽  
Author(s):  
U. Schmidt-Ott ◽  
G.M. Technau

Based on the expression pattern of the segment polarity genes engrailed and wingless during the embryonic development of the larval head, we found evidence that the head of Drosophila consists of remnants of seven segments (4 pregnathal and 3 gnathal) all of which contribute cells to neuromeres in the central nervous system. Until completion of germ band retraction, the four pregnathal segment remnants and their corresponding neuromeres become arranged in an S-shape. We discuss published evidence for seven head segments and morphogenetic movements during head formation in various insects (and crustaceans).

Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1151-1161 ◽  
Author(s):  
Y. Zhang ◽  
A. Ungar ◽  
C. Fresquez ◽  
R. Holmgren

Previous studies have shown that the segment polarity locus gooseberry, which contains two closely related transcripts gooseberry-proximal and gooseberry-distal, is required for proper development in both the epidermis and the central nervous system of Drosophila. In this study, the roles of the gooseberry proteins in the process of cell fate specification have been examined by generating two fly lines in which either gooseberry-distal or gooseberry-proximal expression is under the control of an hsp70 promoter. We have found that ectopic expression of either gooseberry protein causes cell fate transformations that are reciprocal to those of a gooseberry deletion mutant. Our results suggest that the gooseberry-distal protein is required for the specification of naked cuticle in the epidermis and specific neuroblasts in the central nervous system. These roles may reflect independent functions in neuroblasts and epidermal cells or a single function in the common ectodermal precursor cells. The gooseberry-proximal protein is also found in the same neuroblasts as gooseberry-distal and in the descendants of these cells.


2018 ◽  
Vol 94 (1114) ◽  
pp. 446-452 ◽  
Author(s):  
Borros M Arneth

BackgroundThe gut–brain axis facilitates a critical bidirectional link and communication between the brain and the gut. Recent studies have highlighted the significance of interactions in the gut–brain axis, with a particular focus on intestinal functions, the nervous system and the brain. Furthermore, researchers have examined the effects of the gut microbiome on mental health and psychiatric well-being.The present study reviewed published evidence to explore the concept of the gut–brain axis.AimsThis systematic review investigated the relationship between human brain function and the gut–brain axis.MethodsTo achieve these objectives, peer-reviewed articles on the gut–brain axis were identified in various electronic databases, including PubMed, MEDLINE, CIHAHL, Web of Science and PsycINFO.ResultsData obtained from previous studies showed that the gut–brain axis links various peripheral intestinal functions to brain centres through a broad range of processes and pathways, such as endocrine signalling and immune system activation. Researchers have found that the vagus nerve drives bidirectional communication between the various systems in the gut–brain axis. In humans, the signals are transmitted from the liminal environment to the central nervous system.ConclusionsThe communication that occurs in the gut–brain axis can alter brain function and trigger various psychiatric conditions, such as schizophrenia and depression. Thus, elucidation of the gut–brain axis is critical for the management of certain psychiatric and mental disorders.


Development ◽  
1962 ◽  
Vol 10 (2) ◽  
pp. 115-126
Author(s):  
R. T. Sims

The literature on regeneration in the central nervous system of vertebrates has been reviewed exhaustively by Windle (1955, 1956). Adult fish and urodeles reestablish physiological and anatomical continuity of the spinal cord after it has been completely transected while adult anurans (Piatt & Piatt, 1958) and mammals on the whole do not. In all groups of vertebrates regeneration is more successful in the period of early embryonic development, and becomes less so as development proceeds. Experiments designed to investigate the factors responsible for this change demand an animal in which the difference in the regenerative capacity of embryonic and adult form is marked, and all stages of development are easily accessible for operative procedures. These criteria are satisfied by Anura. For this reason regeneration in the anuran central nervous system merits further investigation. After spinal cord transection in urodele larvae, Piatt (1955) found that the Mauthner axons did not regenerate although other axons around them did.


Development ◽  
2001 ◽  
Vol 128 (10) ◽  
pp. 1757-1769 ◽  
Author(s):  
C. Olivier ◽  
I. Cobos ◽  
E.M. Perez Villegas ◽  
N. Spassky ◽  
B. Zalc ◽  
...  

Oligodendrocytes are the myelin-forming cells in the central nervous system. In the brain, oligodendrocyte precursors arise in multiple restricted foci, distributed along the caudorostral axis of the ventricular neuroepithelium. In chick embryonic hind-, mid- and caudal forebrain, oligodendrocytes have a basoventral origin, while in the rostral fore-brain oligodendrocytes emerge from alar territories (Perez Villegas, E. M., Olivier, C., Spassky, N., Poncet, C., Cochard, P., Zalc, B., Thomas, J. L. and Martinez, S. (1999) Dev. Biol. 216, 98–113). To investigate the respective territories colonized by oligodendrocyte progenitor cells that originate from either the basoventral or alar foci, we have created a series of quail-chick chimeras. Homotopic chimeras demonstrate clearly that, during embryonic development, oligodendrocyte progenitors that emerge from the alar anterior entopeduncular area migrate tangentially to invade the entire telencephalon, whereas those from the basal rhombomeric foci show a restricted rostrocaudal distribution and colonize only their rhombomere of origin. Heterotopic chimeras indicate that differences in the migratory properties of oligodendroglial cells do not depend on their basoventral or alar ventricular origin. Irrespective of their origin (basal or alar), oligodendrocytes migrate only short distances in the hindbrain and long distances in the prosencephalon. Furthermore, we provide evidence that, in the developing chick brain, all telencephalic oligodendrocytes originate from the anterior entopeduncular area and that the prominent role of anterior entopeduncular area in telencephalic oligodendrogenesis is conserved between birds and mammals.


2004 ◽  
Vol 47 (4) ◽  
pp. 635-641 ◽  
Author(s):  
Paula Andréa Oliveira Soares ◽  
Jacques Hubert Charles Delabie ◽  
José Eduardo Serrão

Neuropile is the region of the central nervous system where the synapses and neurons branching occur. During the development of an holometabolous insect can occurs break of the neurons fibers forming new axon and dendrites and their distribution in brain neuropile is organized so as to reflect specific nervous functions of adult insects. The components of this organization were observed and discussed in this study in the ant Acromyrmex octospinosus, evidencing similar features to those described for A. subterraneus subterraneus, among other insects for the which ones this information is available.


2018 ◽  
Vol 34 (1) ◽  
pp. 495-521 ◽  
Author(s):  
Michele Curcio ◽  
Frank Bradke

After an injury in the adult mammalian central nervous system (CNS), lesioned axons fail to regenerate. This failure to regenerate contrasts with axons’ remarkable potential to grow during embryonic development and after an injury in the peripheral nervous system (PNS). Several intracellular mechanisms—including cytoskeletal dynamics, axonal transport and trafficking, signaling and transcription of regenerative programs, and epigenetic modifications—control axon regeneration. In this review, we describe how manipulation of intrinsic mechanisms elicits a regenerative response in different organisms and how strategies are implemented to form the basis of a future regenerative treatment after CNS injury.


Development ◽  
1963 ◽  
Vol 11 (1) ◽  
pp. 107-118
Author(s):  
Ujihiro Murakami ◽  
Yoshiro Kameyama

Many experiments have recently been conducted to investigate the effects of oxygen deficiency upon embryonic development. Embryos offish, amphibia and birds have most frequently been used. Of all these experiments, those of Stockard (1921), of Büchner and his co-workers, and particularly of Rübsaamen (1952), were the most striking. Experiments employing mammals have been very few. Subjecting mice to hypoxia in the early stages of pregnancy Ingalls, Curley & Prindle (1950) could analyse the developmental disturbances observable in the offspring. Werthemann, Reiniger & Thoelen (1950) and Werthemann & Reiniger (1950) used the rabbit and rat in similar experiments. Murakami, Kameyama & Kato (1956) exposed pregnant mice to hypoxia on the eighth day of pregnancy and observed malformation of the central nervous system. Vertebrae were found to be malformed by Ingalls & Curley (1957) and by Degenhardt (1954, 1959) after oxygen deficiency. Badtke, Degenhardt & Lund (1959) also described cranio-facial dysplasia in the progeny of rabbits treated with hypoxia.


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