Prenatal carbocyanine dye tracing of septo-hypothalamic connections

2007 ◽  
Vol 1130 ◽  
pp. 38-47 ◽  
Author(s):  
Irina G. Makarenko
Keyword(s):  
Dye Tracing ◽  
Carbocyanine Dye

Segmental and neuronal architecture of the hindbrain of Krox-20 mouse mutants

Development ◽  
1997 ◽  
Vol 124 (6) ◽  
pp. 1215-1226 ◽  
Author(s):  
S. Schneider-Maunoury ◽  
T. Seitanidou ◽  
P. Charnay ◽  
A. Lumsden
Keyword(s):  
Branchial Arch ◽  
Motor Nucleus ◽  
Exit Point ◽  
Dye Tracing ◽  
Trigeminal Motor Nucleus ◽  
Zinc Finger Transcription Factor ◽  
Mouse Mutants ◽  
Neuron Populations ◽  
Carbocyanine Dye ◽  
Internal Architecture

The vertebrate hindbrain is transiently segmented during its early development with the formation of reiterated bulges, the rhombomeres (r). The Krox-20 gene, which encodes a zinc finger transcription factor, has been shown previously to be implicated in the maintenance of r3 and r5 (Schneider-Maunoury, S., Topilko, P., Seitanidou, T., Levi, G., Cohen-Tannoudji, M., Pournin, S., Babinet, C. and Charnay, P. (1993) Cell 75, 1199–1214; Swiatek, P. J. and Gridley, T. (1993) Genes Dev. 7, 2071–2084. However, it was not clear from these analyses how extensive the deletion of r3 and r5 was and whether the overall segmentation and internal architecture of the hindbrain was affected. We have now reinvestigated these issues by analysis of rhombomere boundaries, using both morphological and molecular markers, and of the fate of specific motor neuron populations, using retrograde and anterograde carbocyanine dye tracing. We conclude that r3 and r5 and their derivatives are completely eliminated in Krox-20(−/−) embryos while overall hindbrain segmentation is maintained. In addition, we show that the disappearance of these territories has important consequences for even-numbered rhombomeres as well, in particular on axonal navigation: (i) a population of r6 motoneurons, presumably normally fated to join the glossopharyngeal nerve, has its axons misrouted toward the facial exit point in r4; (ii) the trigeminal motor axons are also misrouted, presumably because of the proximity of the trigeminal and facial exit points. They fasciculate with facial axons outside the neural tube and enter the second branchial arch instead of the first arch. This navigational error could explain the disappearance, at around 17.5 dpc, of the trigeminal motor nucleus in Krox-20(−/−) embryos by inadequate supply of essential, possibly arch-specific survival factors.

scholarly journals Pax6 is required for the normal development of the forebrain axonal connections

Development ◽  
2002 ◽  
Vol 129 (21) ◽  
pp. 5041-5052 ◽  
Author(s):  
Lucy Jones ◽  
Guillermina López-Bendito ◽  
Peter Gruss ◽  
Anastassia Stoykova ◽  
Zoltán Molnár
Keyword(s):  
Knockout Mouse ◽  
Normal Development ◽  
Internal Capsule ◽  
Axonal Guidance ◽  
Pax6 Expression ◽  
Dye Tracing ◽  
Axonal Connections ◽  
Carbocyanine Dye ◽  
Ventral Thalamus ◽  
Guidance Molecule

The transcription factor PAX6 has been implicated in forebrain patterning,cerebral cortical arealization and in development of thalamocortical connections. Using a Pax6/lacZ knockout mouse, in which the endogenous Pax6 expression is reflected by β-galactosidase activity, we have studied the consequences of the loss of Pax6function on thalamocortical (TCA) and corticofugal axon (CFA) pathfinding during the period of embryonic day (E) 14.5 to E18.5. Carbocyanine dye tracing in Pax6 heterozygotes (Pax6+/-) and Pax6wild-type (Pax6+/+) brains revealed that CFAs and TCAs temporarily arrested their growth at E14.5 at the border of theβ-galactosidase-positive region at the pallial/subpallial boundary(PSPB), before they continued towards their targets. However, in Pax6homozygous (Pax6-/-) embryos, CFAs and TCAs were unable to encounter each other at the PSPB and reach their final targets. Instead of crossing the PSPB, they had the tendency to descend into the ventral pallium in large aberrant fascicles. In addition, cells with a presumptive guide-post function, which are normally situated in the ventral thalamus, internal capsule and hypothalamus, were more dispersed in the hypothalamus and ventral pallium. These pathfinding defects were confirmed by immunohistochemistry for L1 and TAG1, markers of the early axonal connections. The aberrant development of axonal connections in absence of Pax6 function appear to be related to ultrastructural defects of cells along the PSPB, as well as to a failure of axonal guidance molecule expression, including Sema3c and Sema5a.

Preplate neurons in embryonic mouse cortex: Ultrastructural observations using photoconversion of the fluorescent lipophilic dye dil

1992 ◽  
Vol 50 (1) ◽  
pp. 906-907
Author(s):  
Linda C. Hassinger ◽  
James E. Crandall
Keyword(s):  
Mouse Embryos ◽  
Embryonic Mouse ◽  
Cortical Afferents ◽  
Mouse Cortex ◽  
Carbocyanine Dye ◽  
Increased Sensitivity

We have begun to look directly at small numbers of afferent axons to early generated neurons that form the preplate in the developing mouse cortex. The carbocyanine dye Dil (1’1, dioctadecyl-3,3,3’3’-tetramethyl-indocarbocyanine) has proved especially useful for this goal. DiI labels axons and their terminals with greater sensitivity and without some of the disadvantages of axon filling with HRP. The increased sensitivity provided by labeling embryonic axons with DiI has given us new insights into the development of cortical afferents. For instance, we reported originally that afferents from the thalamus were present below the cortex as early as embryonic day 15 (E15) based on HRP injections into mouse embryos. By using DiI placements into the thalamus in aldehyde-fixed brains, we now know that thalamic fibers reach the cortex 24 hrs earlier.

scholarly journals Odontoblast processes in dentin revealed by fluorescent Di-I.

1995 ◽  
Vol 43 (2) ◽  
pp. 159-168 ◽  
Author(s):  
M R Byers ◽  
A Sugaya
Keyword(s):  
Electron Microscopy ◽  
Confocal Microscopy ◽  
Cell Structure ◽  
Carbocyanine Dyes ◽  
Carbocyanine Dye ◽  
Reparative Dentin ◽  
Hard Tissues ◽  
Odontoblast Process ◽  
Odontoblast Processes ◽  
Rat Molars

There has been controversy about the length and structure of the odontoblast process within dentin since the earliest histologic studies of teeth. Our objective was to use the fluorescent carbocyanine dye Di-I combined with a new gelatin embedment procedure and confocal microscopy to determine the structure and extent of odontoblast processes in developing and mature rat teeth, injured rat molars, reparative dentin, and adult monkey teeth. We found that odontoblast processes do not extend into outer dentin or to the dentin-enamel junction except during early stages of development. Those in innervated regions of crown are long and straight, whereas those in roots are extensively branched and shorter. Cavity injury to crown dentin caused odontoblast fragments to be aspirated into outer dentin. In reparative dentin the odontoblast processes were branched and similar to those in roots. We used photoconversion and electron microscopy to show that Di-I fills the entire odontoblast after gelatin embedment, including the cytoplasm. This is a different type of carbocyanine staining from any previously reported, and it also stains other cells in adjacent hard tissues such as bone and cementum. The Di-I-gelatin method is a new way to use carbocyanine dyes. It has enabled us to solve a long-standing controversy about the histology of teeth, and it should be useful for many other studies of cell structure.

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