scholarly journals Task- and Time-Dependent Memory Enhancement by Dehydroepiandosterone in Day-Old Chicks

2001 ◽  
Vol 8 (4) ◽  
pp. 255-270 ◽  
Author(s):  
A. N. B. Johnston ◽  
P. V. Migues
Keyword(s):  
Open Field Test ◽  
Time Dependent ◽  
Avoidance Task ◽  
Intracerebral Injection ◽  
Chick Brain ◽  
Memory Enhancement ◽  
Categorization Task ◽  
Visual Categorization ◽  
Per Se ◽  
The Brain

We have previously reported the presence of dehydroepiandosterone (DHEA) in the dayold- chick brain, and a role for it in enhanced memory formation. Here we confirm that intracerebral injections of DHEA 5 min before training on the weak passive avoidance task enhanced recall 24 hours after training. Recall per se on an appetitive visual categorization task was not altered by administration of DHEA 5 min before training. However administration of DHEA 5 min before limited or very limited training on a visual categorization task (20 or 10 pecks only) appeared to enhance consolidation of this task at test 24 h after training; reducing the latency and total time taken to complete the test (60 pecks), while not detrimentally altering accuracy. Moreover, DHEA is unlikely to induce this effect via possible anxiolytic effects because it did not alter behavior in the open field test. We also examined diffusion of DHEA throughout the brain at various stages following intracerebral injection.

Comparison of Cytocidal Activities of L-DOPA and Dopamine in S. cerevisiae and C. glabrata

2020 ◽  
Vol 16 (1) ◽  
pp. 90-93
Author(s):  
Carmen E. Iriarte ◽  
Ian G. Macreadie
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Candida Glabrata ◽  
High Sensitivity ◽  
Time Dependent ◽  
Colony Forming Units ◽  
Dependent Cell ◽  
The Brain

Background: Parkinson's Disease results from a loss of dopaminergic neurons, and reduced levels of the neurotransmitter dopamine. Parkinson's Disease treatments involve increasing dopamine levels through administration of L-DOPA, which can cross the blood brain barrier and be converted to dopamine in the brain. The toxicity of dopamine has previously studied but there has been little study of L-DOPA toxicity. Methods: We have compared the toxicity of dopamine and L-DOPA in the yeasts, Saccharomyces cerevisiae and Candida glabrata by cell viability assays, measuring colony forming units. Results: L-DOPA and dopamine caused time-dependent cell killing in Candida glabrata while only dopamine caused such effects in Saccharomyces cerevisiae. The toxicity of L-DOPA is much lower than dopamine. Conclusion: Candida glabrata exhibits high sensitivity to L-DOPA and may have advantages for studying the cytotoxicity of L-DOPA.

scholarly journals Sotalol does not interfere with the antielectroshock action of selected second-generation antiepileptic drugs in mice

2021 ◽  
Author(s):  
Kinga K. Borowicz-Reutt ◽  
Monika Banach ◽  
Monika Rudkowska ◽  
Anna Stachniuk
Keyword(s):  
Antiepileptic Drugs ◽  
Second Generation ◽  
Antidepressant Drug ◽  
Experimental Models ◽  
Long Term Memory ◽  
Avoidance Task ◽  
Maximal Electroshock ◽  
Term Memory ◽  
The Brain

Abstract Background Due to blocking β-receptors, and potassium KCNH2 channels, sotalol may influence seizure phenomena. In the previous study, we have shown that sotalol potentiated the antielectroshock action of phenytoin and valproate in mice. Materials and methods As a continuation of previous experiments, we examined the effect of sotalol on the action of four chosen second-generation antiepileptic drugs (oxcarbazepine, lamotrigine, pregabalin, and topiramate) against the maximal electroshock in mice. Undesired effects were evaluated in the chimney test (motor impairment) and step-through passive-avoidance task (long-term memory deficits). Finally, brain concentrations of antiepileptics were determined by fluorescence polarization immunoassay, while those of sotalol by liquid chromatography–mass spectrometry. Results Sotalol at doses of up to 100 mg/kg did not affect the electroconvulsive threshold. Applied at doses of 80–100 mg/kg, sotalol did not affect the antielectroshock action of oxcarbazepine, lamotrigine, pregabalin, or topiramate. Sotalol alone and in combinations with antiepileptics impaired neither motor performance nor long-term memory. Finally, sotalol significantly decreased the brain concentrations of lamotrigine and increased those of oxcarbazepine and topiramate. Pharmacokinetic interactions, however, did not influence the final antielectroshock effects of above-mentioned drug combinations. On the other hand, the brain concentrations of sotalol were not changed by second-generation antiepileptics used in this study. Conclusion Sotalol did not reduce the antielectroshock action of four second-generation antiepileptic drugs examined in this study. Therefore, this antidepressant drug should not interfere with antiseizure effects of lamotrigine, oxcarbazepine, pregabalin, and topiramate in patients with epilepsy. To draw final conclusions, our preclinical data should still be confirmed in other experimental models and clinical conditions.

scholarly journals Study on the Dynamic Changes in Synaptic Vesicle-Associated Protein and Axonal Transport Protein Combined with LPS Neuroinflammation Model

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Rui Zhang ◽  
Ming Zhao ◽  
Hai-jie Ji ◽  
Yu-he Yuan ◽  
Nai-hong Chen
Keyword(s):  
Neurodegenerative Disease ◽  
Synaptic Vesicle ◽  
Axonal Transport ◽  
Molecular Mechanism ◽  
Transport Protein ◽  
Microglia Activation ◽  
Time Dependent ◽  
Inflammatory Factors ◽  
Dynamic Changes ◽  
The Brain

Microglia activation is the major component of inflammation that constitutes the characteristic of neurodegenerative disease. A large amount of researches have demonstrated that inflammation involved in the pathogenesis of PD process activated microglia acting on the neurons through the release of a variety of inflammatory factors. However, the molecular mechanism underlying how it does work on neurons is still unclear. Here, we show that intracerebral injections of LPS induced Parkinson’s disease pathology in C57BL/6J mice. Furthermore, study on the dynamic changes in Synaptic vesicle-associated protein and axonal transport Protein in this process. The results indicated that after administration of LPS in the brain, the inflammatory levels of TNF-α and IL-1β both are elevated, and have a time-dependent.

Visual Categorization and Object Representation in Monkeys and Humans

2002 ◽  
Vol 14 (2) ◽  
pp. 187-198 ◽  
Author(s):  
N. Sigala ◽  
F. Gabbiani ◽  
N. K. Logothetis
Keyword(s):  
Object Representation ◽  
Rating Task ◽  
Linear Boundary ◽  
Conditional Probabilities ◽  
Diagnostic Features ◽  
Categorization Task ◽  
Visual Categorization ◽  
Perceptual Features ◽  
Subordinate Categorization

We investigated the influence of a categorization task on the extraction and representation of perceptual features in humans and monkeys. The use of parameterized stimuli (schematic faces and fish) with fixed diagnostic features in combination with a similarity-rating task allowed us to demonstrate perceptual sensitization to the diagnostic dimensions of the categorization task for the monkeys. Moreover, our results reveal important similarities between human and monkey visual subordinate categorization strategies. Neither the humans nor the monkeys compared the new stimuli to class prototypes or based their decisions on conditional probabilities along stimulus dimensions. Instead, they classified each object according to its similarity to familiar members of the alternative categories, or with respect to its position to a linear boundary between the learned categories.

scholarly journals Silver Nanoparticles Impair Cognitive Functions and Modify the Hippocampal Level of Neurotransmitters in a Coating-Dependent Manner

2021 ◽  
Vol 22 (23) ◽  
pp. 12706
Author(s):  
Katarzyna Dziendzikowska ◽  
Małgorzata Węsierska ◽  
Joanna Gromadzka-Ostrowska ◽  
Jacek Wilczak ◽  
Michał Oczkowski ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Spatial Memory ◽  
Antibacterial Properties ◽  
Coating Material ◽  
Long Term Memory ◽  
Avoidance Task ◽  
Dependent Manner ◽  
Memory Functioning ◽  
Place Avoidance ◽  
The Brain

Due to their potent antibacterial properties, silver nanoparticles (AgNPs) are widely used in industry and medicine. However, they can cross the brain–blood barrier, posing a risk to the brain and its functions. In our previous study, we demonstrated that oral administration of bovine serum albumin (BSA)-coated AgNPs caused an impairment in spatial memory in a dose-independent manner. In this study, we evaluated the effects of AgNPs coating material on cognition, spatial memory functioning, and neurotransmitter levels in rat hippocampus. AgNPs coated with BSA (AgNPs(BSA)), polyethylene glycol (AgNPs(PEG)), or citrate (AgNPs(Cit)) or silver ions (Ag+) were orally administered at a dose of 0.5 mg/kg b.w. to male Wistar rats for a period of 28 days, while the control (Ctrl) rats received 0.2 mL of water. The acquisition and maintenance of spatial memory related to place avoidance were assessed using the active allothetic place avoidance task, in which rats from AgNPs(BSA), AgNPs(PEG), and Ag+ groups performed worse than the Ctrl rats. In the retrieval test assessing long-term memory, only rats from AgNPs(Cit) and Ctrl groups showed memory maintenance. The analysis of neurotransmitter levels indicated that the ratio between serotonin and dopamine concentration was disturbed in the AgNPs(BSA) rats. Furthermore, treatment with AgNPs or Ag+ resulted in the induction of peripheral inflammation, which was reflected by the alterations in the levels of serum inflammatory mediators. In conclusion, depending on the coating material used for their stabilization, AgNPs induced changes in memory functioning and concentration of neurotransmitters.

scholarly journals CORTICAL PHASE TRANSITIONS, NONEQUILIBRIUM THERMODYNAMICS AND THE TIME-DEPENDENT GINZBURG–LANDAU EQUATION

2012 ◽  
Vol 26 (06) ◽  
pp. 1250035 ◽  
Author(s):  
WALTER J. FREEMAN ◽  
ROBERTO LIVI ◽  
MASASHI OBINATA ◽  
GIUSEPPE VITIELLO
Keyword(s):  
Phase Transitions ◽  
Landau Equation ◽  
Power Laws ◽  
Time Dependent ◽  
Many Body ◽  
Ginzburg Landau ◽  
Ginzburg Landau Equation ◽  
Characteristic Space ◽  
The Many ◽  
The Brain

The formation of amplitude modulated and phase modulated assemblies of neurons is observed in the brain functional activity. The study of the formation of such structures requires that the analysis has to be organized in hierarchical levels, microscopic, mesoscopic, macroscopic, each with its characteristic space-time scales and the various forms of energy, electric, chemical, thermal produced and used by the brain. In this paper, we discuss the microscopic dynamics underlying the mesoscopic and the macroscopic levels and focus our attention on the thermodynamics of the nonequilibrium phase transitions. We obtain the time-dependent Ginzburg–Landau equation for the nonstationary regime and consider the formation of topologically nontrivial structures such as the vortex solution. The power laws observed in functional activities of the brain is also discussed and related to coherent states characterizing the many-body dissipative model of brain.

Neurological behaviour of albino rats treated separately and in combination with Cannabis sativa L. and Cannabis indica L.

2021 ◽  
Vol 20 (2) ◽  
pp. 37-50
Author(s):  
Joseph S. Ashidi ◽  
Irene. E. Emeya ◽  
Folarin O. Owagboriaye ◽  
Roseline T. Feyisola ◽  
Olubukola I. Lawal ◽  
...  
Keyword(s):  
Open Field ◽  
Field Test ◽  
Cannabis Sativa ◽  
Open Field Test ◽  
Brain Cells ◽  
Control Group ◽  
Albino Rats ◽  
Dopamine Level ◽  
Cannabis Indica ◽  
The Brain

There has been an increasing rate of cannabis consumption globally, especially among the youths. This study therefore evaluated the neurological behaviours and some brain marker hormones and enzymes of cannabis administered rats. Twenty six albino rats were divided into four groups based on oral cannabis administration (control, Cannabis sativa, Cannabis indica and the combination of the two). At the end of seven days, open field test was conducted on the rats. Also, brain neuro-chemicals, activities of antioxidant enzymes and lipid peroxidation were evaluated using spectrophotometry. The results of the Open-Field Test showed an appreciable increase in the level of ambulation (line crossing), grooming, urination and stretched attend posture in the rats administered with Cannabis indica, Cannabis sativa and the combination when compared with the control. Norepinephrine was significantly lower (p < 0.05) in the rat groups administered with the combination of Cannabis indica and Cannabis sativa. The control group however had the lowest dopamine level. Superoxide dismutase (SOD) was significantly lower (p < 0.05) in the rats administered the combination of both Cannabis indica and Cannabis sativa. The brain level of reduced glutathione (GSH) was significantly higher in the rats administered with Cannabis indica. Malondialdehyde (MDA) was significantly higher in the rats administered with Cannabis sativa than the other rat groups. Histopathological evaluation of the brain also revealed various damages in the brain cells of rats administered with cannabis compared to the normal brain structure of the control rats. It is thus said that consumption of C. sativa or C. indica alone produced mild effect on the brain cells and physiology in rats. However, combination of C. sativa and C. indica produced a severe synergistic effect on the neurological function of the exposed rat.

scholarly journals Apolipoprotein E Antibodies Affect the Retention of Passive Avoidance Memory in the Chick

1998 ◽  
Vol 6 (3) ◽  
pp. 29-40 ◽  
Author(s):  
Chris Lancashire ◽  
Radmila Mileusnic ◽  
Steven P.R. Rose
Keyword(s):  
Risk Factors ◽  
Apolipoprotein E ◽  
Passive Avoidance ◽  
Residence Time ◽  
Memory Formation ◽  
Avoidance Task ◽  
Brain Distribution ◽  
The Brain ◽  
Avoidance Memory

Isoforms of apolipoprotein E (ApoE) have been implicated as risk factors in Alzheimer’s disease. We have, therefore, examined the possible role of ApoE in memory formation, using a one-trial passive avoidance task in day-old chicks. Birds were trained on the task and then at various times pre or post-training were injected intracerebrally with anti-ApoE. Immunofluorescence staining demonstrated the presence of the antibody bound to the neuropil, close to the injection site and adjacent to the ventricle, with a residence time in the brain of up to 30 min. Chicks that were injected 30 min pre-training or just post-training with 5μg/ hemisphere of the antibody learned the task, but were amnesic when tested at 30 min or at subsequent times up to 24 hr Post-training. When tested at 24 hr, birds injected 5.5 hr post-training showed unimpaired retention. Birds injected with 5μg/hemisphere of anti-ApoA-I (which has a brain distribution similar to that of anti-ApoE) at 30 min pretraining showed no amnesia, indicating the specificity of the effect to the ApoE. Possible mechanisms for this effect are discussed.

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