Wound Healing In The Hindbrain Of The Chick Embryo

ABSTRACT

The neural folds comprise two epithelial layers, namely, surface epithelium and

neuroepithelium. In the fore and midbrain regions of the chick embryo, neural fold

fusion in the dorsal midline involves a complete fusion of both layers. In the

hindbrain region, however, fusion of the neuroepithelial portion of the neural folds

does not occur. Rather, following apposition of the tips of the neural folds, many

of the neuroepithelial cells that should participate in neural fold fusion undergo

apoptosis. The rest of the neuroepithelial cells in the region of the dorsal midline

undergo rearrangement and flattening to form a single-layered neuroepithelium of

the hindbrain roof plate. It is not clear whether in the light of the above the

hindbrain region may be a weakened portion of the neuraxis, and therefore, be

predisposed to the development of neural tube defects (NTDs). The present study

had a three-fold aim, namely, i) To ascertain whether the hindbrain roof plate at

the time it is undergoing apoptosis possesses the ability to close when it is

reopened through wounding, ii) to determine the mechanisms by which roof plate

closure is achieved in the event of it occurring despite apoptosis iii) to determine

whether wound healing in the hindbrain roof plate affects its morphogenetic

thinning. Chick embryos at stages 11 and 12 of development were wounded in the

dorsal midline of hindbrain rhombomeres rl/r2 and rl-r3, and reincubated for

varying periods of time to allow healing to be effected. At zero hour, the wound

was slit-like or gaped slightly, with the wound edges of the surface epithelium

capping that of the neuroepithelium. Healing of both the surface epithelium and

the neuroepithelium began from the ends of the wound within 30 minutes of

reincubation. Healing of both layers then progressed in a zipper-like manner

towards the middle portion of the wound. The sequence of healing was surface

epithelium first, followed by neuroepithelium. Complete healing occurred in both

rl/r2 and rl-r3 wounds, implying that the length of the wound did not affect the

ability of the hindbrain roof plate to repair itself. Additionally, the longer rl-r3

wounds healed at a faster rate than the shorter rl/r2 wounds such that at any given

time, the average length of wound healed for the two groups (i.e. rl/r2 and rl-r3)

did not differ significantly. Acridine orange histochemistry revealed that apoptosis

in the hindbrain occurred normally in the presence of wound healing leading to the

normal morphogenetic thinning of the hindbrain roof plate. The implication is that

the early embryo has reparative mechanisms in place to ensure that assaults to it

are taken care of, thereby preventing the interference of normal morphogenesis.

Healing of the neuroepithelium in the presence of massive apoptosis suggests that

apoptosis may not likely predispose the hindbrain to the development of NTDs.

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APA

ADUTWUM-OFOSU, K (2021). Wound Healing In The Hindbrain Of The Chick Embryo. Afribary. Retrieved from https://afribary.com/works/wound-healing-in-the-hindbrain-of-the-chick-embryo

MLA 8th

ADUTWUM-OFOSU, KEVIN "Wound Healing In The Hindbrain Of The Chick Embryo" Afribary. Afribary, 08 Apr. 2021, https://afribary.com/works/wound-healing-in-the-hindbrain-of-the-chick-embryo. Accessed 15 Jul. 2024.

MLA7

ADUTWUM-OFOSU, KEVIN . "Wound Healing In The Hindbrain Of The Chick Embryo". Afribary, Afribary, 08 Apr. 2021. Web. 15 Jul. 2024. < https://afribary.com/works/wound-healing-in-the-hindbrain-of-the-chick-embryo >.

Chicago

ADUTWUM-OFOSU, KEVIN . "Wound Healing In The Hindbrain Of The Chick Embryo" Afribary (2021). Accessed July 15, 2024. https://afribary.com/works/wound-healing-in-the-hindbrain-of-the-chick-embryo