UDC 611,314 +616,314] - 091.8 - 092.4
DATE AND ZAKONOMERNOSTI POYAVLENIYA In
NEYROMEDIATOROV
N. In TRIGEMINUS PRENATALNOM ONTOGENEZE RIGHTS
Dossaev TM, Zholdybaeva AA
The
For the development of n. trigeminus in embryogenesis
rights characterized earlier bookmark, the prevalence in the size and degree of
differentiation over other cranial nerves [1.2]. Already in the early stages of
embryogenesis knot trigeminal nerve (Gasserov node)
took considerable space to head the department of undifferentiated embryo. Such
dominance in the early stages of embryogenesis due to the fact that in phylogenesis trigeminal nerve develops as branchiate nerve,
which provides respiratory motion by reducing muscle mandibulyarnoy
arc. In studies of embryogenesis peripheral nervous system and, in particular,
cranial nerves identified some patterns of development trigeminal nerve. For
example, the nerve fibres that form the root originally
tortuosity and among them are found proneyroblasty. Then root knot slightly longer, the number
of fibers in its composition is growing, they lose their tortuosity
and acquire puchkovidnuyu structure [3].
However, embriologicheskie classical studies on the
development of peripheral nervous system of mammals rights and received silver impregnatsii methods do not allow a clear answer to
questions mediatornoy affiliation developing neural
structures as well as characteristics of becoming mediatornogo
period ontogenesis. In connection with this obvious need to complement the
classical neyroembriologicheskih research data
obtained neyrogistohimicheskimi modern methods of
research.
With the formation of the autonomous nervous system, particularly nerve wreath
products of various organs, neuromediators appear in
the nerve fibers did not immediately but after the dendrites, axons, as well as
neyroblasty penetrate into the body or characteristic
in the field of localization nerve junction.
Accordingly, in ontogenesis emit domediatorny and mediatorny stages of development and functioning of the
autonomous nervous system [4]. Time of transition to a stage of development mediatornomu nervous system coincides with the beginning of
fetal period, and it is the time to generate cells-choline
targets - and adrenoretseptorov [5]. Also beginning mediatornogo phase coincides with the active sinaptogenezom and apoptotic elimination of neurons, is not
formed and operated mezhneyronnyh neyrotkanevyh
synaptic connections [6.7].
The development of the autonomous nervous system in embryogenesis happening in
the crane-caudal direction, and also happens geterohronno
top mediators in the synthesis of nerve plexus embryo, starting in the chest,
then in the lumbar and completed in the pelvic plexus. For example, the main
mediator in the beginning to determine nerve plexus 8-9 at heart - and
ontogenesis week, while in kidney only to 10-11 - a week [4.5].
Thus, the study mediatornogo phase of development in
different parts of the autonomic nervous system is a key to understanding the
normal patterns of its subsequent development, and the dynamics of becoming mezhneyronnyh neyrotkanevyh ties
[8.9].
An analysis of the literature indicates that the current stage of development mediatornogo formation of the autonomous nervous system
thoroughly studied in a number of internal organs (heart, kidney, aorta) and to
a much lesser extent in embryogenesis craniocerebral
nerves. Therefore, we set the goal - to explore the dynamics of becoming mediatornogo stage in the n. trigeminus
human embryos.
Material and methods: Study development nerve cell components n. trigeminus human embryos and the formation of mediatornogo phase of the autonomous nervous system
conducted at serial longitudinal and transverse sections of human embryos. The
material of human embryos served 79 terms ranging from 4 - till 12 - and weeks.
The cut-painted on Veygertu Palya,
Wiesel, impregnated silver nitrate on Bilshovskomu Bouquets.
To identify the main neuromediators
on manufactured in the cryostat sections were neyrgistohimicheskuyu
reaction to acetylcholinesterase on Karnovskomu-Roots, and the luminescence catecholamine
incubation sections in glioksilovoy acid.
Results of the study: In reviewing preparations impregnated silver nitrate,
drew the attention severe tortuosity sensitive nerve
fibers and motor roots at an early stage (4 weeks) bookmarks and branches of
the trigeminal nerve in the availability of individual nerve bundles neyroblastov.
At 6 weeks of embryo development Gasserov knot
consisted of a large number of intensely colored neyroblastov
with eccentric located bright nucleus. Sensitive and engine roots, forming a
common trunk of the trigeminal nerve, had puchkovidnoe
structure. Motor root with a medial sensitive, passes on the surface nizhnemedialnoy Gasserova node,
participating in the formation of 3 - y branches of the trigeminal nerve.
Pencils root motor nerve fibers that were part of the n. mabdidularis,
reaching mioblastov forming bookmarks masticatory muscles, and give smaller secondary branches
along the longitudinal axis mioblastov. By that date,
all three branches of n. trigeminus formed densely
located nerve fibers.
A 7-week embryo development Gasserov site continues
to grow in size and consists of a large number of polymorphic neyroblastov various sizes and intensity of colour. Neural fiber roots n. trigeminus
less tortuosity and their number in comparison with
the previous deadlines embryogenesis increases. Gasser node becomes irregular
shape, vypyachivayas forward and upward, toward
bookmarks eye glasses. Nervus ophtalmicus,
starting from this vypyachivaniya, located above eye
glasses and contains in its structure a large number of single neyroblastov.
Nervus maxillaris extends
to the maxillary roller where his secondary branches diverge in different
directions. It traces of motor root fibers that differ more intensive impregnatsiey silver.
Individual single neyroblasty met only in the
proximal maxillary nerve.
Secondary nerve trunks of each branch of the trigeminal nerve are beginning to
emerge from the development of embryos 6.5 weeks and during this period are
intensively impregnated connection through nerve fibers between n. maxillaries
and n. mandibularis.
In parallel with the development of branches of the trigeminal nerve is
happening and develop their parasympathetic ganglia. Already at 6.5 weeks of
embryos is determined ganglion submandidulare
crowding in the form of cell mass. Then, as the embryo, formed consistently
ganglion ciliare, ganglion pterygopalatinum
and ganglion oticum.
When neyrogistohimicheskom study sections on Karnovskomu-Roots from 8 to cholinesterase - and embryos
for the first time in weeks ganglion submandidulare
identified single neurons with holinergicheskie slabovyrazhennoy reaction to the sulphide
copper. Such neurons in the number of 10-
Study sections with incubation in glioksilovoy acid
to detect the emergence of single catecholamines
showed intense fluorescent neurons (SIF cells) from 10 - and near one-week
embryos emerging consistently ganglion ciliare,
ganglion pterygopalatinum and ganglion oticum, as well as along the branches of the trigeminal
nerve.
Near Gasserova node in all cases observed 1-2 paragangliya containing small cells with a weak specific
fluorescence nelyuminestsiruyuschimi nuclei and
cytoplasm.
Also, in most cases, observing the course n. ophtalmicus,
n. maxillaries and n. mandibularis identified group
of neurons shown little specific fluorescence catecholamines.
Conclusions.
1. Forming n. trigeminus
and its main branches in human embryogenesis occurs within 2 - months
intrauterine life in domediatorny stage of the
formation of the autonomous nervous system.
2. Mediatorny
stage of developing n. trigeminus begins with 8 -
second week intrauterine development with the advent of single neurons in the
composition holinergicheskih emerging caudal ganglia.
3. Catecholamine identified single
neurons in only 10 - a week intrauterine development.
4. The emergence of the major
mediators in the nervous structures n. trigeminus
coincides with the period platsentatsii.
5. There geterohroniya
between the formation of nerve-fiber component n. trigeminus
and the beginning of the synthesis of the basic neuromediators,
Literature
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internal organs.
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Summary
Dosan TM, Zholdybaeva AA
C years and the emergence of patterns in neuromediators
n. trigeminus in prenatal human ontogenesis
At the formation of human embryos studied mediatornogo
stage of development in n. glosso r e haryng us. A geterohroniya
between the formation of nerve-fiber component n. glosso
r e haryng us and the emergence of major neuromediators - acetylcholine and catecholamines.
Identified a temporary gap in 2 weeks between the beginning of the synthesis of
acetylcholine and catecholamines.