6 research outputs found
Acetylcholinesterase-positive and paraformaldehyde-induced-fluorescence-positive innervation in the upper eyelid of the sheep (Ovis aries)
This is the first study which describes the innervation of some eyelid structures, such as the glands of Moll and the glands of Zeiss. It is also the first to investigate the innervation pattern of the eyelid as a whole. We have studied the acetylcholinesterase-positive and paraformaldehyde-induced-fluorescence-positive (FIF+) innervation pattern of the different structures that constitute the upper eyelid of the sheep. There is widespread acetylcholinesterase-positive innervation in the epithelium, but not such an abundant FIF+ innervation. Both types of innervation are represented in the connective tissue by trunks or fibers that are distributed towards the different structures immersed within them. In the glands of Zeiss, cholinesterasepositive innervation is much more widespread than FIF innervation. On the contrary, the glands of Moll present denser FIF+ innervation than acetylcholinesterasepositive innervation. The Meibomian glands and the lachrymal glands show a rich acetylcholinesterasepositive and FIF+ innervation. Eyelid muscle innervation is mainly acetylcholinesterase-positive. In the conjunctive membrane there is no acetylcholinesterase-positive innervation, and only scarce FIF+ fibers can be demonstrated
Localization of connexins in neurons and glia cells of the Helix aspersa suboesophageal brain ganglia by immunocytochemistry
8 páginas, 5 figuras.-- et al.The aim of the present study was to examine the distribution of cells expressing connexin 26 (Cx26) in the suboesophageal visceral, left and right parietal and left and right pleural ganglia of the snail Helix aspersa by immunocytochemistry. Altogether we have found approximately 452 immunoreactive neurons which represent the 4.7% of the total neurons counted. The stained large neurons (measured diameter 55-140 µm) occurred mostly on the peripheral surface of the ganglia while the small immunostained cells (5-25 µm diameter) were observed in groups near the neuropil. The number of large neurons giving positive Cx26-like immunostaining was small in comparison with that for medium (30-50 µm diameter) and small sized cells. The expression of Cx26 was also observed in the processes of glia cells localized among neurons somata and in the neuropil showing that the antiserum recognized epitopes in both protoplasmic and fibrous glia cells of Helix aspersa. The neuropils of all ganglia showed fibers densely immunostained. While we have observed a good specificity for Cx26-antiserum in neurons, a lack of reaction for Cx43 antiserum was observed in neurons and glia cells. The reaction for enolase antiserum in neurons was light and non-specific and a lack of reaction in glia cells and processes for GFAP antiserum was observed. Although the percentage of positive neurons for Cx26 antiserum was low is suggested that in normal physiological conditions or under stimulation the expression of connexin could be increased. The observed results can be considered of interest in the interpretation of Helix aspersa elemental two neuron networks synchronizing activity, observed under applied extremely low frequency magnetic fields.This research has received financial support from
“Fundación Humanismo y Ciencia” (Madrid) and from “Diputación General de Aragón” (Spain) under Project B43.Peer reviewe
Enteric plexus and interstitial cells of Cajal, lnterrelationship in the stomach of Podarcis hispanica (Reptilia). An ultrastructural study
The ultrastructure organization of the
stomach enteric plexus was examined in the lizard
Podarcis hispanica. The ganglions of the myenteric
plexus present a low number of nerve cell bodies with a
peculiar nucleus, which occasionally establish direct
contacts with cells of the circular muscle layer. Glial
cells are smaller than the neurones, and their nucleus is
very electron-dense. They surround the axons that
constitute the fibres of the myenteric plexus. Four main
types of axon profile are described in a morphological
consideration of the vesicle population. In the interstice
of the circular muscle layer we describe two types of
interstitial cells that, due to their ultrastructural
characteristics, may be equivalent to the interstitial cells
of Cajal which have been described in mammalians.
These cells shows parallel distribution to the stomach
nerve plexuses, establishing close contacts with them
through their long cytoplasmic prolongations. By means
of small gap-like unions, they contact both each other
and the smooth muscle cells near them. We describe a
submucous plexus, where neuronal bodies are scattered
among bundles of nervous fibres, some of which are
myelinated. A mucous plexus with isolated neurones is
located in the lamina propria. Axonal varicosities
containing vesicles contact with the cells of the mucous.
Interconnected interstitial cells may also be found in this
plexus
Acetylcholinesterase-positive and paraformaldehyde-induced-fluorescence-positive innervation in the upper eyelid of the sheep (Ovis aries)
This is the first study which describes the
innervation of some eyelid structures, such as the glands
of Moll and the glands of Zeiss. It is also the first to
investigate the innervation pattern of the eyelid as a
whole. We have studied the acetylcholinesterase-positive
and paraformaldehyde-induced-fluorescence-positive
(FIF+) innervation pattern of the different structures that
constitute the upper eyelid of the sheep. There is
widespread acetylcholinesterase-positive innervation in
the epithelium, but not such an abundant FIF+
innervation. Both types of innervation are represented in
the connective tissue by trunks or fibers that are
distributed towards the different structures immersed
within them. In the glands of Zeiss, cholinesterasepositive
innervation is much more widespread than FIF
innervation. On the contrary, the glands of Moll present
denser FIF+ innervation than acetylcholinesterasepositive
innervation. The Meibomian glands and the
lachrymal glands show a rich acetylcholinesterasepositive
and FIF+ innervation. Eyelid muscle
innervation is mainly acetylcholinesterase-positive. In
the conjunctive membrane there is no
acetylcholinesterase-positive innervation, and only
scarce FIF+ fibers can be demonstrated
Localization of connexins in neurons and glia cells of the Helix aspersa suboesophageal brain ganglia by immunocytochemistry
The aim of the present study was to examine
the distribution of cells expressing connexin 26 (Cx26)
in the suboesophageal visceral, left and right parietal and
left and right pleural ganglia of the snail Helix aspersa
by immunocytochemistry. Altogether we have found
approximately 452 immunoreactive neurons which
represent the 4.7% of the total neurons counted. The
stained large neurons (measured diameter 55-140 μm)
occurred mostly on the peripheral surface of the ganglia
while the small immunostained cells (5-25 μm diameter)
were observed in groups near the neuropil. The number
of large neurons giving positive Cx26-like
immunostaining was small in comparison with that for
medium (30-50 μm diameter) and small sized cells. The
expression of Cx26 was also observed in the processes
of glia cells localized among neurons somata and in the
neuropil showing that the antiserum recognized epitopes
in both protoplasmic and fibrous glia cells of Helix
aspersa. The neuropils of all ganglia showed fibers
densely immunostained. While we have observed a good
specificity for Cx26-antiserum in neurons, a lack of
reaction for Cx43 antiserum was observed in neurons
and glia cells. The reaction for enolase antiserum in
neurons was light and non-specific and a lack of reaction
in glia cells and processes for GFAP antiserum was
observed. Although the percentage of positive neurons
for Cx26 antiserum was low is suggested that in normal
physiological conditions or under stimulation the results can be considered of interest in the interpretation
of Helix aspersa elemental two neuron networks synchronizing activity, observed under applied
extremely low frequency magnetic fields
Characterization by immunocytochemistry of ionic channels in Helix aspersa suboesophageal brain ganglia neurons
The aim of this work was to characterize
several ionic channels in nervous cells of the
suboesophageal visceral, left and right parietal, and left
and right pleural brain ganglia complex of the snail
Helix aspersa by immunocytochemistry. We have
studied the immunostaining reaction for a wide panel of
eleven polyclonal antibodies raised against mammal
antigens as follows: voltage-gated-Na+ channel; voltagegated-
delayed-rectifier-K+ channel; SK2-smallconductance-
Ca2+-dependent-K+ channel apamin
sensitive; SK3 potassium channel; charybdotoxinsensitive
voltage-dependent potassium channel; BKCamaxi-
conductance-Ca2+-dependent-K+ channel;
hyperpolarization-activated cyclic nucleotide-gated
potassium channel 4; G-protein-activated inwardly
rectifying potassium channel GIRK2 and voltage-gatedcalcium
of L, N and P/Q type channels. Our results show
positive reaction in neurons, but neither in glia cells nor
in processes in the Helix suboesophageal ganglia. Our
results suggest the occurrence of molecules in Helix
neurons sharing antigenic determinants with mammal
ionic channels. The reaction density and distribution of
immunoreactive staining within neurons is specific for
each one of the antisera tested. The studies of colocalization
of immunoreaction, on alternate serial
sections of the anterior right parietal ganglion, have
shown for several recognized mapped neurons that they
can simultaneously be expressed among two and seven
different ionic protein channels. These results are considered a key structural support for the interpretation
of Helix aspersa neuron electrophysiological activity