Nuevos Casos Misteriosos

Childs Nerv Syst (2008) 24:577–580
DOI 10.1007/s00381-007-0527-y

ORIGINAL PAPER

Apoptosis seems to be the major process while surface
and neural ectodermal layers detach during neurulation
Mehmet Selçuki & Seda Vatansever &
Ahmet Sukru Umur & Cuneyt Temiz & Murat Sayin

Received: 26 September 2007 / Published online: 16 November 2007
# Springer-Verlag 2007

Abstract
Objective Theaim of this study is to demonstrate the process of detaching neural and surface ectodermal layers soon
after the neurulation completes.
Materials and methods Specific pathogen-free chicken egg
embryos were used to investigate the neurulation procedure. Ten eggs were saved as controls. The other ten eggs
were opened at the 30th hour of embryo development and
cultured with Z-VAD-FMK (peptidecaspase inhibitor) to
investigate the results of the apoptosis inhibition. Embryos
were placed and developed up to 48 h in the culture medium.
To detect apoptotic cells between neural and surface dermal
layers, immunoreactivity of p53 and terminal uridine deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)
assay were used.
Results While the control group shows positive immunoreactivityof p53 and TUNEL-positive apoptotic cells at the
site where the neural folds detach from the surface ectoderm,
no TUNEL activity and no detachment were detected in the
apoptosis-inhibited group.
This paper was presented at the 35th annual meeting of International
Society of Paediatric Neurosurgery, 9–14 September 2007, Liverpool,
England.
M. Selçuki : A. S. Umur : C. Temiz : M. SayinDepartment of Neurosurgery,
Celal Bayar University School of Medicine,
Manisa, Turkey
S. Vatansever
Department of Histology and Embryology,
Celal Bayar University School of Medicine,
Manisa, Turkey
M. Selçuki (*)
1403 sk 5/8 Alsancak,
35220 Izmir, Turkey
e-mail: mselcuki@yahoo.com

Conclusion As inhibition of apoptosis prevented the detachment of the neural and surface ectodermal layersfrom each
other at the end of the neurulation, inhibition of apoptosis
seemed to cause a considerable embryological error accounted for congenital dermal sinus tractus maldevelopment.
Keywords Neurulation . Dermal sinus tractus . Apoptosis

Introduction
Dermal sinus tract is a rare entity with an estimated incidence of 1:2,500 live births [5]. The embryological
explanation of theirdevelopment has been done by incomplete disjunction of neural and dermal parts of the embryonic
ectoderm [4, 6]. The subsequent disjunction of the dermal
and neural ectodermal layers were believed to be the
consequence of differential adhesion of two tissue types as
far as the molecular biological point of view is concerned.
However, investigation of neural and surface ectodermal
adhesion molecules,N-cadherin and E-cadherin, respectively, did not reveal a convincing evidence for their crucial role
either in fusion of the opposing layers or in separation of the
neural and dermal ectodermal as a result of their differential
adhesion [2]. Although it is known that failure of neurectoderm to separate from the cutaneous ectoderm results in
congenital dermal sinus tractus, the embryologicalerror
accounting for this development is not yet clear. However,
although the exact mechanism is not clear, it seems that there
is a nondisclosed consensus on the importance of process of
apoptosis for disjunction of dermal and neural ectodermal
layers [7]. The aim of this paper is to investigate the
importance of apoptosis in detachment of neural and
ectodermal layers, in which the failure ofthe process will
contribute to formation of congenital dermal sinus tracts.

Childs Nerv Syst (2008) 24:577–580

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Materials and methods
Inhibition of apoptosis
The peptide caspase inhibitor Z-VAD-FMK was purchased
from Enzyme System Products (Dublin, CA, USA) and
used at a final concentration of 200 μM. Stock solution of
the inhibitor was prepared in dry dimethyl sulphoxide and...