Prolonged retention of the anorectic cobalt protoporphyrin in the hypothalamus and the resulting expression of Fos

2004 ◽  
Vol 287 (2) ◽  
pp. R465-R471 ◽  
Author(s):  
Richard A. Galbraith ◽  
Ilean Hodgdon ◽  
Michele S. Grimm ◽  
Margaret A. Vizzard
Keyword(s):  
Male Rats ◽  
Halothane Anesthesia ◽  
Short Term ◽  
Brain Areas ◽  
Duration Of Action ◽  
Prolonged Duration ◽  
Cobalt Protoporphyrin ◽  
Prolonged Retention ◽  
The Brain

The anorectic cobalt protoporphyrin (CoPP) is known to elicit short-term hypophagia and long-term weight loss through unknown mechanisms in the brains of experimental animals. The goal of this work was to determine 1) if the prolonged duration of action of CoPP is related to its prolonged retention within the brain; and 2) with the use of immunohistochemical detection of Fos, the product of the early-immediate gene c-fos, which cells are activated after exposure to CoPP. These studies were carried out in male rats after intracerebroventricular administration of CoPP, 0.4 μmol/kg body wt, given under light halothane anesthesia. Residence of CoPP in the brain was determined by residual counts in dissected brains of 57CoPP-injected rats. Fos immunoreactivity was mapped in coronal sections of rat brains 4–6 h after injection with CoPP. The results showed that 57CoPP was retained in the hypothalamus preferentially compared with the cortex of the brain and could be detected in the hypothalamus for in excess of 5 wk. Fos activation was increased by CoPP, detected predominantly in neuronal rather than glial cells, and was markedly more robust in the hypothalamus than in other brain areas. Thus CoPP remains in the hypothalamus for prolonged periods and activates Fos expression in the hypothalamus.

scholarly journals Dynamic Alterations of miR-34c Expression in the Hypothalamus of Male Rats after Early Adolescent Traumatic Stress

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Chuting Li ◽  
Yuan Liu ◽  
Dexiang Liu ◽  
Hong Jiang ◽  
Fang Pan
Keyword(s):  
Traumatic Stress ◽  
Memory Impairment ◽  
Term Effect ◽  
Male Rats ◽  
Early Adolescent ◽  
Short Term ◽  
Corticotrophin Releasing Factor ◽  
Long Term Effect ◽  
The Brain

Several types of microRNA (miRNA) overexpression in the brain are associated with stress. One of the targets of miR-34c is the stress-related corticotrophin releasing factor receptor 1 mRNA (CRFR1 mRNA). Here we will probe into the short-term effect and long-term effect of early adolescent traumatic stress on the expression of miR-34c and CRFR1 mRNA. Traumatic stress was established by electric foot shock for six consecutive days using 28-day rats. The anxiety-like behaviors, memory damage, CRFR1 protein, CRFR1 mRNA, and miR-34c expression were detected in our study. The results of our study proved that exposure to acute traumatic stress in early adolescent can cause permanent changes in neural network, resulting in dysregulation of CRFR1 expression and CRFR1 mRNA and miR-34c expression in hypothalamus, anxiety-like behavior, and memory impairment, suggesting that the miR-34c expression in hypothalamus may be an important factor involved in susceptibility to PTSD.

scholarly journals Short-term and long-term international scientific mobility of Italian PhDs: An analysis by gender

2021 ◽  
pp. 35-40
Author(s):  
Valentina Tocchioni ◽  
Alessandra Petrucci ◽  
Alessandra Minello
Keyword(s):  
Multinomial Logistic Regression ◽  
Early Career ◽  
International Mobility ◽  
Short Term ◽  
Host Countries ◽  
Academic Mobility ◽  
Positive Effects ◽  
Long Run ◽  
The Brain

In the last years, there has been a large increase in high-educated and high-skilled people’s mobility as a consequence of the internationalization and globalization, the weakening of research and university systems of sending countries (the “brain drain” process), the increase in skilled demand and improvements in higher education of host countries (the “brain gain” process). At the micro-level, academic mobility has positive consequences on occupational prospects and careers of researchers, both in the short- and long- run. Nevertheless, numerous research studies have demonstrated the challenges of engaging in international academic mobility for people with caring responsibilities, particularly women. Using Italian data on occupational conditions of PhDs collected in 2018 by Istat and modelling multinomial logistic regression analyses, we intend to verify if female researchers are associated with a lower international mobility irrespective their field of study, and the extent to which gender interacts differently in the various fields of study in affecting the probability of moving abroad after PhD qualification. Also, the distinction between long-term and short-term mobility, which has been mainly neglected in the literature concentrating on longer stays, has taken into account. In this respect, short-term mobility is a potentially high-value investment that may be pursued also by those researchers and scientists who cannot move for longer periods, such as women with caring responsibilities. In the literature, it is acknowledged that an experience abroad during early career may have positive effects on future occupational prospects. With our work, we intend to shed light on potential disparities on moving abroad that may exist among researchers in their early career by gender, and which could contribute to leave behind women in academia.

scholarly journals Functional Connectivity within Brain Networks of Long Term and Short term Meditators

2019 ◽  
Vol 9 (2S) ◽  
pp. 29-34
Keyword(s):  
Functional Connectivity ◽  
Temporal Correlation ◽  
Brain Regions ◽  
Invasive Technique ◽  
Long Term Effects ◽  
Short Term ◽  
Statistical Concept ◽  
The Brain ◽  
Meditative Practices

Meditation refers to a state of mind of relaxation and concentration, where generally the mind and body is at rest. The process of meditation reflects the state of the brain which is distinct from sleep or typical wakeful states of consciousness. Meditative practices usually involve regulation of emotions and monitoring of attention. Over the past decade there has been a tremendous increase in an interest to study the neural mechanisms involved in meditative practices. It could also be beneficial to explore if the effect of meditation is altered by the number of years of meditation practice. Functional Magnetic Resonance Imaging (fMRI) is a very useful imaging technique which can be used to perform this analysis due to its inherent benefits, mainly it being a non-invasive technique. Functional activation and connectivity analysis can be performed on the fMRI data to find the active regions and the connectivity in the brain regions. Functional connectivity is defined as a simple temporal correlation between anatomically separate, active neural regions. Functional connectivity gives the statistical dependencies between regional time series. It is a statistical concept and is quantified using metrics like Correlation. In this study, a comparison is made between functional connectivity in the brain regions of long term meditation practitioners (LTP) and short-term meditation practitioners (STP) to see the differences and similarities in the connectivity patterns. From the analysis, it is evident that in fact there is a difference in connectivity between long term and short term practitioners and hence continuous practice of meditation can have long term effects.

scholarly journals New cerebrovascular agent with hypotensive activity

2019 ◽  
Vol 5 (2) ◽  
pp. 71-77
Author(s):  
Galina A. Kim ◽  
Tamara S. Gan’shina ◽  
Elena V. Kurza ◽  
Ilya N. Kurdyumov ◽  
Denis V. Maslennikov ◽  
...  
Keyword(s):  
Blood Flow ◽  
Antihypertensive Agent ◽  
Brain Injuries ◽  
Cerebrovascular Disorders ◽  
Male Rats ◽  
Hypotensive Activity ◽  
Duration Of Action ◽  
Ischemic Brain ◽  
Cerebrovascular Activity ◽  
The Brain

Introduction: In cerebrovascular disorders, special attention is paid to a hypertensive cerebrovascular crisis, which combines a vascular injury of the brain and hypertension. The paper studies the cerebrovascular properties of the calcium channel blocker of S-Amlodipine nicotinate antihypertensive agent. Materials and methods: Tests were performed on 96 nonlinear male rats, measuring local blood flow in the cerebral cortex in 36 awake animals, using a laser Doppler flowmeter. Cerebral circulation was recorded in the animals when modeling ischemic and hemorrhagic brain injuries. Results and discussion: S-Amlodipine nicotinate (0.1 mg/kg i/v) shows a pronounced cerebrovascular activity in the models of ischemic and hemorrhagic injuries of the brain. In terms of the vasodilating effect in ischemic brain injury, the drug is comparable to mexidol, nimodipine, picamilon, but is superior to nimodipine and picamilon in terms of duration of action, and in the model of hemorrhagic stroke, S-Amlodipine nicotinate is superior to nimodipine and is comparable to picamilon and mexidol. The analysis of the mechanism of action of the agent revealed the participation of GABA A-receptors in the implementation of cerebrovascular properties of the agent. Conclusion: Significant cerebrovascular activity of S-Amlodipine nicotinate (0.1 mg/kg i/v) antihypertensive agent was revealed. The presence of GABAergic mechanism on cerebral blood flow in the agent action along with blockade of slow calcium channels ensures its high efficacy in treatment of both ischemic and hemorrhagic brain injuries.

Effects of adrenocorticotropin on temperature- and pressure-dependent metabolic functions

1959 ◽  
Vol 197 (6) ◽  
pp. 1291-1296 ◽  
Author(s):  
Henry B. Hale ◽  
Roy B. Mefferd
Keyword(s):  
Barometric Pressure ◽  
Male Rats ◽  
Short Term ◽  
Metabolic Functions ◽  
Metabolic States ◽  
Environmental Extremes ◽  
Temperature And Pressure ◽  
Hot Environments ◽  
Low Dosage

Effects of adrenocorticotropin (ACTH) in low dosage on metabolic aspects were determined in adult male rats acclimated to cold, neutral or hot environments or to low barometric pressure. Urinary determinations provided the means for indirectly assessing metabolic states. The metabolic aspects studied were Na, K, Ca, P, Mg, urea, uric acid, creatinine, creatine, taurine, ß-alanine, glycine, α-alanine, valine, methionine, serine, threonine, tyrosine, glutamic acid, aspartic acid, lysine, arginine, histidine, glucose, glucuronic acid, phenolic acids and coproporphyrin. Additionally, fecal determinations were made for coproporphyrin, protoporphyrin and deuteroporphyrin. The interplay between endocrine and environmental factors and their importance to metabolic states during short-term and long-term exposures to environmental extremes thus received some clarification. With the low dosage employed, ACTH had a ‘restraining’ influence on nonspecific metabolic responses.

A Mathematical Model of Short-Term Memory

SIMULATION ◽  
1964 ◽  
Vol 3 (6) ◽  
pp. 46-51
Author(s):  
W. Ross Adey ◽  
N.V. Findler
Keyword(s):  
Electromagnetic Waves ◽  
Short Term Memory ◽  
Threshold Value ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Neuron Density ◽  
Receptor Neurons ◽  
The Brain

It is attempted in this paper to give a mathematical description of the short-term memory. Instead of using the microscopic properties of individual neu rons, such as the number of interconnections, neuron density, threshold value, etc., the cerebral cortex is regarded as a "neuron gas" that is a vast conglomer ate of neurons with statistically distributed charac teristics. Stimuli from the environment cause the receptor neurons to emit virtual electromagnetic waves into the brain. A self-optimizing process of the brain tis sue is here described by which the useful, informa tion-carrying energy reaching the long-term memory tends to maximum. It is emphasized that in the following a brain model is described and the physical processes in volved may have no direct equivalent in reality.

In vitro pituitary GH secretion after GHRH, forskolin, dibutyryl cyclic-adenosine 3′,5′-monophosphate and phorbol 12-myristate 13-acetate stimulation in long-term orchidectomized rats

1996 ◽  
Vol 16 (1) ◽  
pp. 81-88 ◽  
Author(s):  
M Tena-Sempere ◽  
L Pinilla ◽  
E Aguilar
Keyword(s):  
Male Rats ◽  
Short Term ◽  
Compensatory Mechanisms ◽  
Gh Secretion ◽  
Camp Pathway ◽  
Kinase C ◽  
High Doses

ABSTRACT In the present work in vitro GH pituitary responsiveness to GHRH in short-term (STO) and long-term orchidectomized (LTO) male rats was compared. In agreement with previous data obtained in vivo, pituitaries from STO rats showed reduced GH release after GHRH stimulation while LTO male pituitaries presented responses similar to those from control animals after maximal GHRH (10-6 m) stimulation. This suggests that compensatory mechanisms have taken place, probably at the pituitary level, in order to restore GH pituitary responsiveness to high doses of GHRH. However, LTO male rats showed a reduced sensitivity to GHRH relative to intact males, as indicated by a higher EC50 vs controls (40·82 ± 12·03 nm vs 0·35 ± 0·09 nm in intact males). We aimed to investigate further the events involved in the compensatory mechanisms that take place in LTO rats. For this purpose, we compared in vitro GH secretion by pituitaries from intact and LTO male rats after stimulation with specific activators of the signal transduction pathways related to GH release. Forskolin and dibutyryl cyclic-adenosine 3′,5′-monophosphate were more effective in eliciting GH secretion (expressed in terms of percent increment over basal GH release) in LTO males, whereas phorbol 12-myristate 13-acetate was completely ineffective in stimulating GH release in this group. Thus, our results clearly showed that long-term orchidectomy enhances the effectiveness of the cAMP pathway in inducing GH release while it completely blunts that of the protein kinase C pathway. In conclusion, orchidectomy decreased the effectiveness of GHRH in eliciting GH release in vitro. However, long-term orchidectomy activated compensatory mechanisms that restored complete GH pituitary responsiveness to maximal GHRH stimulation. These mechanisms seem not to operate in STO rats. An increased effectiveness of the cAMP pathway in eliciting GH release in LTO rats is probably involved in the aforementioned compensatory mechanisms.

scholarly journals Prolonged Systemic Inflammation Alters Muscarinic Long-Term Potentiation (mLTP) in the Hippocampus

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Efrat Shavit-Stein ◽  
Amir Dori ◽  
Marina Ben Shimon ◽  
Shany Guly Gofrit ◽  
Nicola Maggio
Keyword(s):  
Cognitive Impairment ◽  
Systemic Inflammation ◽  
Long Term Potentiation ◽  
Short Exposure ◽  
Short Term ◽  
Cholinergic Dysfunction ◽  
Term Potentiation ◽  
Hippocampal Synapses ◽  
The Brain

The cholinergic system plays a fundamental role in learning and memory. Pharmacological activation of the muscarinic receptor M1R potentiates NMDA receptor activity and induces short-term potentiation at the synapses called muscarinic LTP, mLTP. Dysfunction of cholinergic transmission has been detected in the settings of cognitive impairment and dementia. Systemic inflammation as well as neuroinflammation has been shown to profoundly alter synaptic transmission and LTP. Indeed, intervention which is aimed at reducing neuroinflammatory changes in the brain has been associated with an improvement in cognitive functions. While cognitive impairment caused either by cholinergic dysfunction and/or by systemic inflammation suggests a possible connection between the two, so far whether systemic inflammation affects mLTP has not been extensively studied. In the present work, we explored whether an acute versus persistent systemic inflammation induced by LPS injections would differently affect the ability of hippocampal synapses to undergo mLTP. Interestingly, while a short exposure to LPS resulted in a transient deficit in mLTP expression, a longer exposure persistently impaired mLTP. We believe that these findings may be involved in cognitive dysfunctions following sepsis and possibly neuroinflammatory processes.

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