scholarly journals Neuromediator systems in some brain regions of rats subjected to morphine intoxication

2010 ◽  
Vol 56 (5) ◽  
pp. 562-569
Author(s):  
S.V. Lelevich ◽  
A.A. Novokshonov
Keyword(s):  
Brain Stem ◽  
Brain Tissue ◽  
Brain Regions ◽  
Cerebral Hemispheres ◽  
Serotonin Level ◽  
Chronic Morphine ◽  
Chronic Morphine Intoxication ◽  
System Functioning ◽  
Gaba Content ◽  
The Brain

The content of neuromediators and its metabolites in the cortex of cerebral hemispheres, in thalamus and brain stem was studied under chronic morphine intoxication (7-21 days). The morphine intake during 7-14 days was accompanied by changes of catecholamine system functioning, which was the most pronounced in the thalamus and the brain stem. These changes included increased secretion of dophamine and noradrenaline, their decrease in the brain tissue, and the increased content of their metabolites. The changes of serotonin and GABA content were less pronounced and included a decrease of serotonin level and the increase of the GABA content in different periods of narcotization.

Symptoms, Related Brain Regions, and Diagnosis

2013 ◽  
Author(s):  
J. Eric Ahlskog
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Basal Ganglia ◽  
Brain Stem ◽  
Muscle Activation ◽  
Sensory Information ◽  
Brain Regions ◽  
Electrical Signal ◽  
Brain And Spinal Cord ◽  
The Brain

As a prelude to the treatment chapters that follow, we need to define and describe the types of problems and symptoms encountered in DLB and PDD. The clinical picture can be quite varied: problems encountered by one person may be quite different from those encountered by another person, and symptoms that are problematic in one individual may be minimal in another. In these disorders, the Lewy neurodegenerative process potentially affects certain nervous system regions but spares others. Affected areas include thinking and memory circuits, as well as movement (motor) function and the autonomic nervous system, which regulates primary functions such as bladder, bowel, and blood pressure control. Many other brain regions, by contrast, are spared or minimally involved, such as vision and sensation. The brain and spinal cord constitute the central nervous system. The interface between the brain and spinal cord is by way of the brain stem, as shown in Figure 4.1. Thought, memory, and reasoning are primarily organized in the thick layers of cortex overlying lower brain levels. Volitional movements, such as writing, throwing, or kicking, also emanate from the cortex and integrate with circuits just below, including those in the basal ganglia, shown in Figure 4.2. The basal ganglia includes the striatum, globus pallidus, subthalamic nucleus, and substantia nigra, as illustrated in Figure 4.2. Movement information is integrated and modulated in these basal ganglia nuclei and then transmitted down the brain stem to the spinal cord. At spinal cord levels the correct sequence of muscle activation that has been programmed is accomplished. Activated nerves from appropriate regions of the spinal cord relay the signals to the proper muscles. Sensory information from the periphery (limbs) travels in the opposite direction. How are these signals transmitted? Brain cells called neurons have long, wire-like extensions that interface with other neurons, effectively making up circuits that are slightly similar to computer circuits; this is illustrated in Figure 4.3. At the end of these wire-like extensions are tiny enlargements (terminals) that contain specific biological chemicals called neurotransmitters. Neurotransmitters are released when the electrical signal travels down that neuron to the end of that wire-like process.

Simulation of Brain Response to Noncontact Impacts Using Coupled Eulerian–Lagrangian Method

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Miao Na ◽  
Timothy J. Beavers ◽  
Abhijit Chandra ◽  
Sarah A. Bentil
Keyword(s):  
Brain Tissue ◽  
Mechanical Response ◽  
Brain Regions ◽  
Von Mises Stress ◽  
Fe Model ◽  
Brain Response ◽  
Fe Method ◽  
Angular Velocities ◽  
Von Mises ◽  
The Brain

Abstract Finite element (FE) method has been widely used for gaining insights into the mechanical response of brain tissue during impacts. In this study, a coupled Eulerian−Lagrangian (CEL) formulation is implemented in impact simulations of a head system to overcome the mesh distortion difficulties due to large deformation in the cerebrospinal fluid (CSF) region and provide a biofidelic model of the interaction between the brain and skull. The head system used in our FE model is constructed from the transverse section of the human brain, with CSF modeled by Eulerian elements. Spring connectors are applied to represent the pia-arachnoid connection between the brain and skull. Validations of the CEL formulation and the FE model are performed using the experimental results. The dynamic response of brain tissue under noncontact impacts and the brain regions susceptible to injury are evaluated based on the intracranial pressure (ICP), maximum principal strain (MPS), and von Mises stress. While tracking the critical MPS location on the brain, higher likelihood of contrecoup injury than coup injury is found when sudden brain−skull motion takes place. The accumulation effect of CSF in the ventricle system, under large relative brain−skull motion, is also identified. The FE results show that adding relative angular velocities, to the translational impact model, not only causes a diffuse high strain area, but also cause the temporal lobes to be susceptible to cerebral contusions since the protecting CSF is prone to be squeezed away at the temporal sites due to the head rotations.

Chemical targeting of voltage sensitive dyes to specific cells and molecules in the brain

2020 ◽  
Author(s):  
Tomas Fiala ◽  
Jihang Wang ◽  
Matthew Dunn ◽  
Peter Šebej ◽  
Se Joon Choi ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Brain Tissue ◽  
Fluorescent Dyes ◽  
Brain Slices ◽  
Brain Regions ◽  
Expression Levels ◽  
Specific Targeting ◽  
The Impact ◽  
Voltage Sensitive Dyes ◽  
The Brain

Voltage sensitive fluorescent dyes (VSDs) are important tools for probing signal transduction in neurons and other excitable cells. These sensors, rendered highly lipophilic to anchor the conjugated pi-wire molecular framework in the membrane, offer several favorable functional parameters including fast response kinetics and high sensitivity to membrane potential changes. The impact of VSDs has, however, been limited due to the lack of cell-specific targeting methods in brain tissue or living animals. We address this key challenge by introducing a non-genetic molecular platform for cell- and molecule-specific targeting of synthetic voltage sensitive dyes in the brain. We employ a dextran polymer particle to overcome the inherent lipophilicity of voltage sensitive dyes by dynamic encapsulation, and high-affinity ligands to target the construct to specific neuronal cells utilizing only native components of the neurotransmission machinery at physiological expression levels. Dichloropane, a monoamine transporter ligand, enables targeting of dense dopaminergic axons in the mouse striatum and sparse noradrenergic axons in the mouse cortex in acute brain slices. PFQX in conjunction with ligand-directed acyl imidazole chemistry enables covalent labeling of AMPA-type glutamate receptors in the same brain regions. Probe variants bearing either a classical electrochromic ANEP dye or state-of-the-art VoltageFluor-type dye respond to membrane potential changes in a similar manner to the parent dyes, as shown by whole-cell patch recording. We demonstrate the feasibility of optical voltage recording with our probes in brain tissue with one-photon and two-photon fluorescence microscopy and define the signal limits of optical voltage imaging with synthetic sensors under a low photon budget determined by the native expression levels of the target proteins. We envision that modularity of our platform will enable its application to a variety of molecular targets and sensors, as well as lipophilic drugs and signaling modulators. This work demonstrates the feasibility of a chemical targeting approach and expands the possibilities of cell-specific imaging and pharmacology.

Regional Quantification of Brain Tissue Strain Using Displacement-Encoding With Stimulated Echoes Magnetic Resonance Imaging

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Soroush Heidari Pahlavian ◽  
John Oshinski ◽  
Xiaodong Zhong ◽  
Francis Loth ◽  
Rouzbeh Amini
Keyword(s):  
Magnetic Resonance Imaging ◽  
Corpus Callosum ◽  
Brain Stem ◽  
Brain Tissue ◽  
Neural Tissue ◽  
Resonance Imaging ◽  
Tissue Strain ◽  
The Brain ◽  
Tissue Motion ◽  
Principal Strains

Intrinsic cardiac-induced deformation of brain tissue is thought to be important in the pathophysiology of various neurological disorders. In this study, we evaluated the feasibility of utilizing displacement encoding with stimulated echoes (DENSE) magnetic resonance imaging (MRI) to quantify two-dimensional (2D) neural tissue strain using cardiac-driven brain pulsations. We examined eight adult healthy volunteers with an electrocardiogram-gated spiral DENSE sequence performed at the midsagittal plane on a 3 Tesla MRI scanner. Displacement, pixel-wise trajectories, and principal strains were determined in seven regions of interest (ROI): the brain stem, cerebellum, corpus callosum, and four cerebral lobes. Quantification of small neural tissue motion and strain along with their spatial and temporal variations in different brain regions was found to be feasible using DENSE. The medial and inferior brain structures (brain stem, cerebellum, and corpus callosum) had significantly larger motion and strain compared to structures located more peripherally. The brain stem had the largest peak mean displacement (PMD) (187 ± 50 μm, mean ± SD). The largest mean principal strains in compression and extension were observed in the brain stem (0.38 ± 0.08%) and the corpus callosum (0.37 ± 0.08%), respectively. Measured values in percent strain were altered by as much as 0.1 between repeated scans. This study showed that DENSE can quantify regional variations in brain tissue motion and strain and has the potential to be utilized as a tool to evaluate the changes in brain tissue dynamics resulting from alterations in biomechanical stresses and tissue properties.

Focal warming in the nucleus of the solitary tract prolongs the laryngeal chemoreflex in decerebrate piglets

2007 ◽  
Vol 102 (1) ◽  
pp. 54-62 ◽  
Author(s):  
L. Xia ◽  
T. A. Damon ◽  
J. C. Leiter ◽  
D. Bartlett
Keyword(s):  
Brain Stem ◽  
Brain Tissue ◽  
Rectal Temperature ◽  
Respiratory Activity ◽  
Nucleus Ambiguus ◽  
Tissue Temperature ◽  
Whole Body ◽  
Solitary Tract ◽  
Neonatal Piglets ◽  
The Brain

The laryngeal chemoreflex (LCR), elicited by a drop of water in the larynx, is exaggerated by mild hyperthermia (body temperature = 40–41°C) in neonatal piglets. We tested the hypothesis that thermal prolongation of the LCR results from heating the nucleus of the solitary tract (NTS), where laryngeal afferents first form synapses in the brain stem. Three- to 13-day-old piglets were decerebrated and vagotomized and studied without anesthesia while paralyzed and ventilated. Phrenic nerve activity and rectal temperature were recorded. A thermode was placed in the medulla, and the brain tissue temperature was recorded with a thermistor ∼1 mm from the tip of the thermode. When the thermode was inserted into the brain stem, respiratory activity was arrested or greatly distorted in eight animals. However, the thermode was inserted in nine animals without disrupting respiratory activity, and in these animals, warming the medullary thermode (thermistor temperature = 40–41°C) while holding rectal temperature constant reversibly exaggerated the LCR. The caudal raphé was warmed focally by ∼2°C in four additional animals; this did not alter the duration of the LCR in these animals. Thermodes placed in the NTS did not disrupt respiratory activity, but they did prolong the LCR when warmed. Thermodes that were placed deep to the NTS in the region of the nucleus ambiguus disrupted respiratory activity, which precluded any analysis of the LCR. We conclude that prolongation of the laryngeal chemoreflex by whole body hyperthermia originates from the elevation of brain tissue temperature within in the NTS.

scholarly journals EXPERIMENTAL STUDIES ON ENCEPHALITIS

1935 ◽  
Vol 61 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Leslie T. Webster ◽  
George L. Fite
Keyword(s):  
Brain Stem ◽  
Brain Tissue ◽  
Kansas City ◽  
Experimental Studies ◽  
Pyramidal Cells ◽  
Time Of Death ◽  
Experimental Encephalitis ◽  
Cornu Ammonis ◽  
Mononuclear Leucocytes ◽  
The Brain

1. Mice of special strains injected intracerebrally with a 10 per cent emulsion of bacteria-free brain tissue from fatal cases of encephalitis in St. Louis and Kansas City develop a characteristic and fatal encephalitis. 2. Transmission of the disease can be continued indefinitely by injecting the bacteria-free brain tissue from the infected mice into healthy mice. 3. In the injected mice there is a 3 to 4 day incubation period, followed by hyperesthesia, coarse tremors, convulsions, prostration, and death in from 4 to 6 days. 4. The lesions in the mice with experimental encephalitis consist chiefly of perivascular accumulations of mononuclear leucocytes throughout the brain, stem, cord, and the pia, and destruction of pyramidal cells in the lobus piriformis and cornu Ammonis. 5. The human encephalitis brain tissue preserved in glycerine from the time of death of the patient apparently loses its infectivity for mice in about 32 days.

Exposure to 835 MHz radiofrequency electromagnetic field induces autophagy in hippocampus but not in brain stem of mice

2017 ◽  
Vol 34 (1) ◽  
pp. 23-35 ◽  
Author(s):  
Ju Hwan Kim ◽  
Da-Hyeon Yu ◽  
Hyo-Jeong Kim ◽  
Yang Hoon Huh ◽  
Seong-Wan Cho ◽  
...  
Keyword(s):  
Brain Stem ◽  
Mobile Phones ◽  
Hippocampal Neurons ◽  
Brain Regions ◽  
Pcr Analysis ◽  
Limited Information ◽  
The Central Nervous System ◽  
Neuronal Functions ◽  
Adaptation Processes ◽  
The Brain

The exploding popularity of mobile phones and their close proximity to the brain when in use has raised public concern regarding possible adverse effects from exposure to radiofrequency electromagnetic fields (RF-EMF) on the central nervous system. Numerous studies have suggested that RF-EMF emitted by mobile phones can influence neuronal functions in the brain. Currently, there is still very limited information on what biological mechanisms influence neuronal cells of the brain. In the present study, we explored whether autophagy is triggered in the hippocampus or brain stem after RF-EMF exposure. C57BL/6 mice were exposed to 835 MHz RF-EMF with specific absorption rates (SAR) of 4.0 W/kg for 12 weeks; afterward, the hippocampus and brain stem of mice were dissected and analyzed. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis demonstrated that several autophagic genes, which play key roles in autophagy regulation, were significantly upregulated only in the hippocampus and not in the brain stem. Expression levels of LC3B-II protein and p62, crucial autophagic regulatory proteins, were significantly changed only in the hippocampus. In parallel, transmission electron microscopy (TEM) revealed an increase in the number of autophagosomes and autolysosomes in the hippocampal neurons of RF-EMF-exposed mice. The present study revealed that autophagy was induced in the hippocampus, not in the brain stem, in 835 MHz RF-EMF with an SAR of 4.0 W/kg for 12 weeks. These results could suggest that among the various adaptation processes to the RF-EMF exposure environment, autophagic degradation is one possible mechanism in specific brain regions.

scholarly journals Distribution of multiple sclerosis lesions detected by brain magnetic resonance imaging in Erbil city

2021 ◽  
Vol 25 (1) ◽  
pp. 446-455
Author(s):  
Dina Tawfeeq ◽  
Shawnam Dawood
Keyword(s):  
Magnetic Resonance Imaging ◽  
Multiple Sclerosis ◽  
Magnetic Resonance ◽  
Corpus Callosum ◽  
Brain Stem ◽  
Signal Intensity ◽  
Brain Regions ◽  
Multiple Sclerosis Lesion ◽  
Resonance Imaging ◽  
The Brain

Background and objective: Many epidemiological studies and clinical manifestation studies of multiple sclerosis have been done in Iraq. Up to our knowledge, no such observational study to the radiological feature of the multiple sclerosis lesion has been done yet in Erbil in comparison to other worldwide studies. This study aimed to assess the distribution of multiple sclerosis lesions in brain regions detected by magnetic resonance imaging among Erbil population. Methods: This was a cross-sectional study conducted at the College of Medicine, Hawler Medical University, from April 2018 to July 2019. A review of magnetic resonance imaging scans of the brain of 120 patients was done. Special attention was directed toward identifying the variance in multiple sclerosis lesions distribution in the brain regions and their MR signal intensity characteristics. Results: Periventricular lesions were observed in more than 90% of the study sample. The next common was juxtacortical lesions (24.8%), followed by corpus callosum lesions (16.8 %), while brain stem lesions were the least observed proportions. No significant difference was detected in the distribution of multiple sclerosis lesions among ethnicities and genders, except for basal ganglia lesions, which were significantly more common in women (P = 0.016).The magnetic resonance imaging signal intensity of the lesion was significantly variable among disease duration. Conclusion: The T2 hyper intense lesions were most commonly seen in the periventricular region. Juxtacortical and corpus callosum lesions were also frequently observed. The proportions of the brain stem and cerebellum lesions appeared to be lower in comparison to previous studies. Keywords: Multiple Sclerosis; Magnetic Resonance Imaging; Distribution; Lesion.

scholarly journals Osteopontin/Secreted Phosphoprotein-1 Behaves as a Molecular Brake Regulating the Brain Translocator Protein-Dependent Neuroinflammatory Response to Chronic Viral Infection

2020 ◽  
Author(s):  
Farina J Mahmud ◽  
Yong Du ◽  
Elizabeth Greif ◽  
Thomas Boucher ◽  
Robert F Dannals ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Brain Tissue ◽  
Calcium Binding ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Brain Regions ◽  
Translocator Protein ◽  
Positron Emission ◽  
Molecular Brake ◽  
The Brain

Abstract Background Osteopontin (OPN) as a secreted signaling protein, is dramatically induced in response to cellular injury and neurodegeneration. Microglial inflammatory responses in the brain are tightly associated with the neuropathologic hallmarks of neurodegenerative disease, but understanding of the molecular mechanisms remains in several contexts, poorly understood. Methods Positron emission tomography (PET) neuroimaging using radioligands to detect increased expression of the translocator protein (TSPO) receptor in the brain, is a non-invasive tool used to track neuroinflammation in living mammals. Results In humanized, chronically HIV-infected mice in which OPN expression was knocked down with functional aptamers, uptake of TSPO radioligand, DPA-713 was markedly upregulated in the hippocampus, cortex, olfactory bulb, cerebellum and significantly increased in other key brain regions analyzed compared to controls. TSPO+ microglia were detected by immunolabeling of post-mortem brain tissue, thus validating the neuroimaging findings. Unexpectedly, two types of neurons also selectively stained positively for TSPO. The reactive cells were the specialized neurons of the cerebellum, Purkinje cells, and a subset of tyrosine hydroxylase positive neurons of the substantia nigra. Two-way ANOVA of immunoreactivity revealed that a well-validated marker of microglial activation in brain tissue, ionized calcium-binding adaptor molecule-1 (Iba-1) was significantly increased, in an interaction that depended on HIV replication. Interestingly, similar analyses of TSPO immunoreactivity showed a significant interaction with OPN expression. Conclusions Collectively, these findings using a model of chronic HIV-infection revealed for the first time two key findings: 1) two different pathways of neuroinflammation are activated, and 2) osteopontin acts as a molecular brake regulating in the brain, the inflammatory response to HIV infection.

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