14 research outputs found
Distribution of neuronal nitric oxide synthase (nNOS)-immunoreactive elements in the rabbit piriform cortex
The piriform cortex (PC), the primary olfactory cortex, is involved in the processes
of learning and stress response and possibly plays an important role in epileptogenic
activity. The results of several recent studies suggest that those PC neurons
that contain neuronal nitric oxide synthase (nNOS) may play a key role
during spatial learning and in the modulation of initiation, propagation and
generalisation of seizures in various experimental models and may influence
neuronal vulnerability after epileptic insults. The aim of this study was to characterise
the pattern of distribution and morphology of nNOS-immunoreactive elements
in PC of the adult rabbit. The co-localisation of nNOS and calretinin (CR)
was also studied. The pattern of nNOS-ir within the rabbit PC is similar to that
described previously in other mammals. The morphology of nNOS-ir elements,
namely varicose fibres and Cajal-Retzius cells, suggest that NO has an important
influence on PC function. Surprisingly, in the rabbit PC nNOS-ir elements show
a very low level of co-localisation with CR-ir
Changes in the morphology of the acinar cells of the rat pancreas in the oedematous and necrotic types of experimental acute pancreatitis
Limited experimental models of the oedematous and necrotic types of acute
pancreatitis provide some understanding of the pathophysiology of this disease.
Wistar rats were treated with cerulein at 10 mg/kg of body weight or with
L-arginine at 1.5 or 3 g/kg of body weight in order to induce the oedematous or
necrotic type of acute pancreatitis. After the induction period we examined
samples of pancreata with light and electron microscopes. Morphological
examination showed profound changes in the histology of the pancreas and its
acinar cells and subcellular structures, especially in the group of rats which
received a higher dose of L-arginine, amounting to 3 g/kg body weight. These
included parenchymal haemorrhage and widespread acinar cell necrotic changes.
4-OH-TEMPO successfully prevented morphological deterioration as well as
amylase release, suggesting that the severity of the two types of disease strongly
depends on the intensity of the oxidative stress. Our results lend support to the
assumption that reactive oxygen species play an axial role in the pathogenesis of
both types of acute pancreatitis
The influence of acute and chronic open-field exposure on the hippocampal formation: an immunohistochemical study
The hippocampus plays a role in new learning, memory and emotion and is
a component of the neuroanatomical stress circuit. The structure is involved in
terminating hypothalamic-pituitary-adrenocortical (HPA) axis responses to stress
and attenuates stress responses by shutting off this axis.
The immunoreactivity (-ir) of c-Fos, NGF and its receptor TrkA following acute and
chronic open-field stress were studied in CA1-CA3 and the DG of the hippocampus.
The material consisted of 21 male adult rats divided into three groups: nonstressed
(control) animals and rats exposed to acute (15 min once) and chronic
(15 min daily for 21 days) aversive stimulation (open-field exposure). The brains
were stained with use of immunohistochemical methods for c-Fos, NGF or TrkA.
In the animals exposed to acute open-field stress the number of c-Fos-, TrkAand
NGF-ir cells was higher in all the structures studied than in the control animals.
However they were differentiated only in c-Fos immunoreactivity.
In the rats exposed to chronic open-field stress the number of c-Fos-ir cells in the
structures of the hippocampal formation studied was smaller than in rats exposed
to acute stress and was comparable to that in the control group. No differences
were observed between the groups exposed to acute and chronic stress in the
number of TrkA-ir cells in the structures under investigation. The number of NGF-ir
neurons in CA1 and CA2 was lower after exposure to chronic than after exposure
to acute stress but was still higher than that in the control group.
Our findings indicate that neurons of CA1-CA3 and the DG are engaged in the
stress response after acute as well as chronic open-field exposure. This is probably
related to the important role of the hippocampus in processing new spatial
information as well as in the habituation processes, although these appear to
have different mechanisms
The immunoreactivity of c-Fos, NGF and its receptor TrkA after open-field exposure in the central and medial nuclei of the rat amygdala
The amygdala is a critical component of the neuroanatomical stress circuit. It
plays a role in the generation of responses to emotional stimuli. The central
(CeA) and medial (MeA) amygdaloid nuclei are implicated in activation of the
hypothalamic-pituitary-adrenocortical (HPA) axis.
The immunoreactivity (-ir) of c-Fos, NGF and its receptor, TrkA, following acute
and chronic open-field stress were studied in the CeA and MeA nuclei of the
amygdala. The material consisted of 21 male adult rats divided into three groups:
non-stressed (control) animals, rats exposed to acute (once only lasting 15 min)
and chronic (15 min daily over 21 days) aversive stimulation (open-field exposure).
The brains were stained with the use of immunohistochemical methods
for c-Fos, NGF or TrkA.
In the control rats c-Fos-, TrkA- and NGF-ir cells were observed in the nuclei
studied, but the quantity varied, being moderate or high (immunoreactive to
TrkA and NGF) or low (immunoreactive to c-Fos).
In the animals exposed to acute open-field stress the number of c-Fos-ir, NGF-ir
and TrkA-ir cells in the nuclei under examination was differentiated but higher
than that in the control animals.
In the animals exposed to chronic open-field stress the number of c-Fos-ir cells
in the nuclei studied was similar and was smaller than those in animals exposed
to acute stress. The number of TrkA-ir neurons was also lower in comparison to
that in animals exposed to acute stress. However, no significant differences in
the number of NGF-ir cells were observed between the groups exposed to acute
and chronic stress.
Diverse expression of c-Fos protein following both acute and chronic stress stimulation
may prove the functional heterogeneity of the amygdaloid nuclei investigated.
The decrease observed in both c-Fos- and TrkA-ir in MeA (only TrkA in
CeA) of animals exposed to chronic stress may indicate the phenomenon of
habituation
Controlled cholesterol efflux from the aortic smooth muscle cells triggers microheterogeneity of plasma membrane lipids and induces modification of the mitochondrial topology
It is generally accepted that phospholipids of plasma membrane display lateral
segregation into small microdomains commonly known as lipid rafts. Such lateral
lipid organization is under the control of cholesterol. Cholesterol depletion
evolved by methyl-β-cyclodextrin (MCD) has been found to induce further
marked perturbation in lateral lipid organization, evidenced in the high field
part of electron paramagnetic resonance spectra of plasma membranes labelled
with a spectroscopic probe, namely 5-doxyl-stearic acid (5DOXS). Such
perturbation of surface lipid topo-logy has been found to induce distinct changes
in the mitochondrial morpho-logy, i.e. switch from filamentous form into small
granular form
Stress-induced changes of interleukin-1β within the limbic system in the rat
The aim of this study was to investigate the influence of two periods of life,
namely P28 and P360, on the changes in interleukin-1beta (IL-1β) immunoreactivity
(-ir) in the hippocampus (CA1, CA3, DG) and amygdala (central-CeA,
medial-MeA) caused by acute and repeated open field (OF), or by forced swim
(FS) exposition. Rats were divided into groups: non-stressed, exposed to acute
(one-time for 15 min) and chronic stressors (21 days for 15 min daily). We
found IL-1β-ir in the control group to be higher in P360 than in P28. In P28,
under OF and FS exposure, IL-1β-ir in the CeA remained unaltered but increased
in the MeA and in the hippocampus after acute and chronic stress. In P360 no
changes were observed in the IL-1β-ir level after acute and chronic stimulation.
These data demonstrate that only the levels of IL-1β-ir in juvenile rat brains are
affected by FS and OF. Additionally, there was no significant difference between
FS and OF stimulation in IL-1β-ir
4-OH-TEMPO prevents the morphological alteration of rat thymocytes primed to apoptosis by oxidative stress inducer ButOOH
Thymocytes exposed to the pro-oxidant tert–butyl-hydroperoxide (ButOOH) display
a number of dramatic changes in morphology similar to those observed in
the case of dexamethasone-treated cells. Both reagents induce nuclear chromatin
peripheral aggregation below the nuclear membrane. Some nuclei themselves
break up producing two or more fragments. ButOOH-treated cells are
morphologically characterised by cell shrinkage, extensive surface blebbing and,
finally, fragmentation into membrane–bound apoptotic bodies composed of
cytoplasm and tightly packed with or without nuclear fragments. An increased
level of lipid hydroxyperoxides was detected after exposure of thymocytes to
ButOOH. Both oxidative stress markers and morphological damage to cells were
prevented by the antioxidant 4-OH-TEMPO
Recommended from our members
Spring 1959
Seed testing - A Service for You by Miss Jessie L. Anderson (page 1) Increased Interest in Two-Year Turf Course by Fred P. Jeffrey - Director of Stockbridge (4) From the Editor (4) Message From Winter School President of 1959 (5) Turf club News (6) Number One Graduate (8) Liquid Fertilization by A.B. Longo (9) Public School Grounds by James Woodhouse (12) Comments on the 1959 Winter School (14) Picture - Stockbridge Turf Majors (16) Picture - Honorary Members of Turf Management Club (17) Letter on Chemical Compatibility (18) The Most Outstanding Turf Senior for 1958 (19) What it Means to be a Turf Manager by R. Russell (20) 10 Steps to a Better Lawn by P. Pedrazzi (24) A Scene to Remember (25) I switched from Hots to Cools by J. Spodnik (26) Why Attend Turfgrass Conferences (27) Picture - Winter School for Turf Managers - 1959 (29) Picture - University of Masssachusetts Annual Turfgrass Conference (30) Organic Fertilizers by O.J. Noer (A-1) Inorganic Fertilizers by Charles Winchell (A-1) Urea Formaldehyde by G.F. Stewart (A-2) Phosphorus and Potash Fertilization by Raph Donaldson (A-3) Questions on Fertilization to the Panel (A-4) Cemetery Maintenance by S.E. Robbins (A-6) Lime by Anson Brewer (A-6) Limited Budgets by R.W. Sharkey (A-7) Fertilization of Park Turf by E.J. Pyle (A-7) Disease and Insect Control by Orlando Capizzi (A-8) Cost of Establishing Turf by Victor Taricano (A-9) Question and Answers (A-10) Control of Pests of Ornamentals and Turf Occuring on Golf Courses by John C. Schread (A-12) Behind the Scenes in Soil Testing and What it Means to You Bertram Gersten and Wm. G. Colby (A-19) Lessons Learned from the 1958 Season as Applied to Golf Course Maintenance by A.M. Radko (A-21) The Outlook in Chemical Weed Control on Fine Turf by John Gallagher (A-24) New Developments in Turfgrass Disease Diagnosis and Control by Frank Howard (A-26
Stress-induced changes of interleukin-1beta within the limbic system in the rat
The aim of this study was to investigate the influence of two periods of life, namely P28 and P360, on the changes in interleukin-1beta (IL-1beta) immunoreactivity (-ir) in the hippocampus (CA1, CA3, DG) and amygdala (central-CeA, medial-MeA) caused by acute and repeated open field (OF), or by forced swim (FS) exposition. Rats were divided into groups: non-stressed, exposed to acute (one-time for 15 min) and chronic stressors (21 days for 15 min daily). We found IL-1beta-ir in the control group to be higher in P360 than in P28. In P28, under OF and FS exposure, IL-1beta-ir in the CeA remained unaltered but increased in the MeA and in the hippocampus after acute and chronic stress. In P360 no changes were observed in the IL-1beta-ir level after acute and chronic stimulation. These data demonstrate that only the levels of IL-1beta-ir in juvenile rat brains are affected by FS and OF. Additionally, there was no significant difference between FS and OF stimulation in IL-1beta-ir