scholarly journals Simulated Microgravity Subtlety Changes Monoamine Function across the Rat Brain

2021 ◽  
Vol 22 (21) ◽  
pp. 11759
Author(s):  
Alexandra Gros ◽  
Léandre Lavenu ◽  
Jean-Luc Morel ◽  
Philippe De Deurwaerdère
Keyword(s):  
Simulated Microgravity ◽  
Brain Area ◽  
Red Nucleus ◽  
Brain Regions ◽  
Cognitive Networks ◽  
Male Rats ◽  
Adaptive Responses ◽  
Motor Systems ◽  
Short Period ◽  
Tissue Contents

Microgravity, one of the conditions faced by astronauts during spaceflights, triggers brain adaptive responses that could have noxious consequences on behaviors. Although monoaminergic systems, which include noradrenaline (NA), dopamine (DA), and serotonin (5-HT), are widespread neuromodulatory systems involved in adaptive behaviors, the influence of microgravity on these systems is poorly documented. Using a model of simulated microgravity (SMG) during a short period in Long Evans male rats, we studied the distribution of monoamines in thirty brain regions belonging to vegetative, mood, motor, and cognitive networks. SMG modified NA and/or DA tissue contents along some brain regions belonging to the vestibular/motor systems (inferior olive, red nucleus, cerebellum, somatosensorily cortex, substantia nigra, and shell of the nucleus accumbens). DA and 5-HT contents were reduced in the prelimbic cortex, the only brain area exhibiting changes for 5-HT content. However, the number of correlations of one index of the 5-HT metabolism (ratio of metabolite and 5-HT) alone or in interaction with the DA metabolism was dramatically increased between brain regions. It is suggested that SMG, by mobilizing vestibular/motor systems, promotes in these systems early, restricted changes of NA and DA functions that are associated with a high reorganization of monoaminergic systems, notably 5-HT.

Dobutamine as a countermeasure for reduced exercise performance of rats exposed to simulated microgravity

1997 ◽  
Vol 82 (5) ◽  
pp. 1607-1615 ◽  
Author(s):  
Charles M. Tipton ◽  
Lisa A. Sebastian
Keyword(s):  
Lactic Acid ◽  
Exercise Performance ◽  
Simulated Microgravity ◽  
Maximal Exercise ◽  
Blood Gases ◽  
Chronic Administration ◽  
Mechanical Efficiency ◽  
Male Rats ◽  
Double Product ◽  
Run Time

Tipton, Charles M., and Lisa A. Sebastian. Dobutamine as a countermeasure for reduced exercise performance of rats exposed to simulated microgravity. J. Appl. Physiol. 82(5): 1607–1615, 1997.—Post-spaceflight results and findings from humans and rodents after conditions of bed rest or simulated microgravity indicate maximum exercise performance is significantly compromised. However, the chronic administration of dobutamine (a synthetic adrenomimetic) to humans in relevant experiments improves exercise performance by mechanisms that prevent the decline in peak O2 consumption (V˙o 2 peak) and reduce the concentration of lactic acid measured in the blood. Although dobutamine restores maximumV˙o 2values in animals participating in simulated microgravity studies, it is unknown whether injections of this α1-, β1-, and β2-adrenoceptor agonist in rats will enhance exercise performance. To investigate this, adult male rats were assigned to three experimental groups: caged control receiving saline; head-down, tail-suspended (HDS) receiving saline (HDS-S); and an HDS group receiving dobutamine hydrochloride injections (1.8 mg/kg twice daily per rat). Treadmill tests were performed before suspension, at 14 days, and after 21 days.V˙o 2 peak, run time, and the rate of rise in colonic temperature (heating index) were evaluated after 14 days, whereas at 21 days, hemodynamic responses (heart rate, systolic blood pressure, and double product) were determined during submaximal exercise with blood pH, blood gases, and lactic acid concentration values obtained during maximal exercise. In contrast to the results for the HDS-S rats, dobutamine administration did restore V˙o 2 peakand “normalized” lactic acid concentrations during maximal exercise. However, daily injections were unable to enhance exercise performance aspects associated with treadmill run time, the mechanical efficiency of running, the heating index, or the retention of muscle and body mass. These simulated microgravity findings suggest that dobutamine’s potential value as a countermeasure for postflight maximal performance or for egress emergencies is limited and that other countermeasures must be considered.

scholarly journals Quantitative RT-PCR analyses of five evolutionary conserved genes in Alligator brains during development

2011 ◽  
Vol 2 (4) ◽  
Author(s):  
Sarah Wilson ◽  
Tianli Zhu ◽  
Rajesh Khanna ◽  
Michael Pritz
Keyword(s):  
Gene Expression ◽  
Brain Area ◽  
Brain Regions ◽  
Adult Brain ◽  
Time Interval ◽  
Conserved Genes ◽  
Mrna Gene ◽  
Alligator Mississipiensis ◽  
Mrna Gene Expression ◽  
Present Gene

AbstractGene expression was investigated in the major brain subdivisions (telencephalon, diencephalon, midbrain and hindbrain) in a representative reptile, Alligator mississipiensis, during the later stages of embryonic development. The following genes were examined: voltage-gated sodium channel isoforms: NaV1.1 and NaV1.2; synaptic vesicle 2a (SV2a); synaptophysin; and calbindin 2. With the exception of synaptophysin, which was only expressed in the telencephalon, all genes were expressed in all brain regions sampled at the time periods examined. For NaV1.1, gene expression varied according to brain area sampled. When compared with NaV1.1, the pattern of NaV1.2 gene expression differed appreciably. The gene expression of SV2a was the most robust of any of the genes examined. Of the other genes examined, although differences were noted, no statistically significant changes were found either between brain part or time interval. Although limited, the present analysis is the first quantitative mRNA gene expression study in any reptile during development. Together with future experiments of a similar nature, the present gene expression results should determine which genes are expressed in major brain areas at which times during development in Alligator. When compared with other amniotes, these results will prove useful for determining how gene expression during development influences adult brain structure.

Abstract P730: MCA Stroke Chronically Disrupts Hippocampal Activity and Cortico-Hippocampal Communication

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Zachary Ip ◽  
Gratianne Rabiller ◽  
Jiwei He ◽  
Shivalika Chavan ◽  
Yasuo Nishijima ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Memory Function ◽  
Brain Regions ◽  
Male Rats ◽  
Brain State ◽  
Signal Power ◽  
Hippocampal Function ◽  
Electrode Arrays ◽  
Mca Occlusion ◽  
Hippocampal Activity

Introduction: Cognition and memory deficits are common sequelae following middle cerebral artery (MCA) stroke, one of the most common strokes in humans. However MCA stroke does not compromise the structural integrity of the hippocampus, which is highly involved in memory function, because the MCA does not supply blood flow to the hippocampus. We previously reported on the acute effect of MCA stroke, where we observed increased hippocampal activity and cortico-hippocampal communication. Here we investigate chronic changes to local oscillations and cortico-hippocampal communication following MCA occlusion in rats two weeks and one month following stroke. Hypothesis: Cortical stroke affects remote brain regions, disrupting hippocampal function and cortico-hippocampal communication. Methods: We subjected male rats (n=28) to distal MCA occlusion compared to controls (n=19). We recorded local field potentials simultaneously from cortex and hippocampus two weeks and one month following stroke using 16-site linear electrode arrays under urethane anesthesia. We analyzed signal power, brain state, CFC, and sharp wave SPW-Rs to assess hippocampal function and cortico-hippocampal communication. Results: Our results show disruptions to local oscillations; lowered delta (1-3 Hz) signal power in the cortex and hippocampus, increased signal power in gamma (30-60 Hz) and high gamma (60-200 Hz) in cortex and hippocampus. Theta/delta brain state is disrupted, and SPW-Rs increase in power at two weeks, before returning to baseline levels at one month. Communication is also disrupted; Theta-gamma coupling, a measure of information being communicated between regions, breaks down after stroke. Conclusions: These results suggest that chronic stroke causes significant changes to hippocampal function, which can be characterized by these electrophysiological biomarkers, establishing putative targets for targeted stimulation therapies.

Refining the Effects Observed in a Developmental Neurobehavioral Study of Ammonium Perchlorate Administered Orally in Drinking Water to Rats. II. Behavioral and Neurodevelopment Effects

2005 ◽  
Vol 24 (6) ◽  
pp. 451-467 ◽  
Author(s):  
Raymond G. York ◽  
John Barnett ◽  
Michael F. Girard ◽  
David R. Mattie ◽  
Marni V. K. Bekkedal ◽  
...  
Keyword(s):  
Drinking Water ◽  
Ammonium Perchlorate ◽  
Brain Regions ◽  
Male Rats ◽  
Male Rat ◽  
Sprague Dawley ◽  
Continuous Access ◽  
Brain Morphometry ◽  
The Central Nervous System ◽  
The Right

A developmental neurotoxicity study was conducted to generate additional data on the potential functional and morphological hazard to the central nervous system caused by ammonium perchlorate in offspring from in utero and lactation exposure. Female Sprague-Dawley rats (23 to 25/group) were given continuous access to 0 (carrier), 0.1, 1.0, 3.0, and 10.0 mg/kg-day perchlorate in the drinking water beginning 2 weeks prior to mating and continuing through day 10 of lactation for the behavioral function assessment or given continuous access to 0 (carrier), 0.1, 1.0, 3.0, and 30.0 mg/kg-day beginning on gestation day 0 and continuing through day 10 of lactation for neurodevelopment assessments. Motor activity was conducted on postpartum days 14, 18, and 22 and juvenile brain weights, neurohistopathological examinations, and regional brain morphometry were conducted on postpartum days 10 and 22. This research revealed a sexually dimorphic response, with some brain regions being larger in perchlorate-treated male rats than in comparable controls. Even so, there was no evidence of any obvious exposure-related effects on male rat brain weights or neuropathology. The most consistent exposure-related effect in the male pups was on the thickness of the corpus callosum, with both the right- and left-sided measures of the thickness of this white matter tract being significantly greater for the male pups in the 0.1 and 1.0 mg/kg-day exposure groups. The behavioral testing suggests prenatal exposure to ammonium perchlorate does not affect the development of gross motor movements in the pups.

scholarly journals Red nucleus IL-33 facilitates the early development of mononeuropathic pain in male rats by inducing TNF-α through activating ERK, p38 MAPK, and JAK2/STAT3

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Hao-Nan Li ◽  
Qing-Qing Yang ◽  
Wen-Tao Wang ◽  
Xue Tian ◽  
Fan Feng ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Early Development ◽  
Red Nucleus ◽  
Neutralizing Antibody ◽  
Male Rats ◽  
Post Injury ◽  
Pain Model ◽  
Mechanical Hypersensitivity ◽  
Downstream Signaling ◽  
Tnf Α

Abstract Background Our recent studies have identified that the red nucleus (RN) dual-directionally modulates the development and maintenance of mononeuropathic pain through secreting proinflammatory and anti-inflammatory cytokines. Here, we further explored the action of red nucleus IL-33 in the early development of mononeuropathic pain. Methods In this study, male rats with spared nerve injury (SNI) were used as mononeuropathic pain model. Immunohistochemistry, Western blotting, and behavioral testing were used to assess the expressions, cellular distributions, and actions of red nucleus IL-33 and its related downstream signaling molecules. Results IL-33 and its receptor ST2 were constitutively expressed in the RN in naive rats. After SNI, both IL-33 and ST2 were upregulated significantly at 3 days and peaked at 1 week post-injury, especially in RN neurons, oligodendrocytes, and microglia. Blockade of red nucleus IL-33 with anti-IL-33 neutralizing antibody attenuated SNI-induced mononeuropathic pain, while intrarubral administration of exogenous IL-33 evoked mechanical hypersensitivity in naive rats. Red nucleus IL-33 generated an algesic effect in the early development of SNI-induced mononeuropathic pain through activating NF-κB, ERK, p38 MAPK, and JAK2/STAT3, suppression of NF-κB, ERK, p38 MAPK, and JAK2/STAT3 with corresponding inhibitors markedly attenuated SNI-induced mononeuropathic pain or IL-33-evoked mechanical hypersensitivity in naive rats. Red nucleus IL-33 contributed to SNI-induced mononeuropathic pain by stimulating TNF-α expression, which could be abolished by administration of inhibitors against ERK, p38 MAPK, and JAK2/STAT3, but not NF-κB. Conclusions These results suggest that red nucleus IL-33 facilitates the early development of mononeuropathic pain through activating NF-κB, ERK, p38 MAPK, and JAK2/STAT3. IL-33 mediates algesic effect partly by inducing TNF-α through activating ERK, p38 MAPK and JAK2/STAT3.

scholarly journals Effects of early neonatal proinflammatory stress on the expression of BDNF transcripts in the brain regions of prepubertal male rats

2016 ◽  
Vol 20 (2) ◽  
pp. 191-197
Author(s):  
D. I. Peregud ◽  
S. V. Freiman ◽  
A. O. Tishkina ◽  
L. S. Sokhranyaeva ◽  
N. A. Lazareva ◽  
...  
Keyword(s):  
Brain Regions ◽  
Male Rats ◽  
The Brain

scholarly journals Brain Activation of College Students in China With Premenstrual Syndrome Localized by BOLD-fMRI

2021 ◽  
Author(s):  
Dongmei Gao ◽  
Mingzhou Gao ◽  
Li An ◽  
Yanhong Yu ◽  
Jieqiong Wang ◽  
...  
Keyword(s):  
College Students ◽  
Premenstrual Syndrome ◽  
Brain Area ◽  
Inferior Frontal Gyrus ◽  
Brain Regions ◽  
Anterior Lobe ◽  
Middle Temporal Gyrus ◽  
Cerebellar Tonsil ◽  
Bold Fmri ◽  
Significant Difference

Abstract Background: Most studies on the mechanism behind premenstrual syndrome (PMS) have focused on fluctuating hormones, but little evidence exists regarding functional abnormalities in the affected brain regions of college students. Thus, the aim of this study is to localize PMS's abnormal brain regions by BOLD-fMRI in college students.Methods: Thirteen PMS patients and fifteen healthy control (HC) subjects underwent a BOLD-fMRI scan during the luteal phase induced by depressive emotion pictures. The BOLD-fMRI data were processed by SPM 8 software and rest software based on MATLAB platform. Each cluster volume threshold (cluster) was greater than 389 continuous voxels, and the brain area with single voxel threshold P < 0.05 (after correction) was defined as the area with a significant difference. The emotion report form and the instruction implementation checklist were used to evaluate the emotion induced by picture.Results: Compared to the HC, right inferior occipital gyrus, right middle occipital gyrus, right lingual gyrus, right fusiform gyrus, right inferior temporal gyrus, cerebelum_crus1_R，cerebelum_6_R, culmen, the cerebellum anterior lobe, tuber, cerebellar tonsil of PMS patients were enhanced activation. Sub-lobar，sub-gyral，extra-nuclear，right orbit part of superior frontal gyrus, right middle temporal gyrus, right Orbit part of inferior frontal gyrus, limbic lobe, right insula, bilateral anterior and adjacent cingulate gyrus, bilateral caudate, caudate head, bilateral putamen, left globus pallidus were decreased activation.Conclusion: Our findings may improve our understanding of the neural mechanisms involved in PMS.

Thallium Induced Changes in Behavioral Patterns: Correlation With Altered Lipid Peroxidation and Lysosomal Enzyme Activity in Brain Regions of Male Rats

1985 ◽  
Vol 1 (1) ◽  
pp. 81-98 ◽  
Author(s):  
David R. Brown ◽  
Barbara G. Callahan ◽  
Mark A. Cleaves ◽  
Robert A. Schatz
Keyword(s):  
Lipid Peroxidation ◽  
Lysosomal Enzyme ◽  
Brain Regions ◽  
Male Rats ◽  
Patterns Of Behavior ◽  
Low Levels ◽  
Behavioral Sequelae ◽  
Human Poisoning ◽  
And Function ◽  
Induced Changes

The effects of exposures to low levels of heavy metals is a complex and serious problem. Thallium is a metal which produces behavioral sequelae in human poisoning and is potentially hazardous with low level exposures. A test battery is presented which utilizes biochemical and behavioral testing to assess the effects of low levels of thallium on central nervous system chemistry and function in rats. The doses of thallium used (4 and 8 mg/kg) produced no overt signs of behavioral toxicity but did produce dose-related increases in lipid peroxidation and activation of the lysosomal enzyme beta-galactosidase in selected brain regions. At these dose levels, thallium also selectively altered the patterns of behavior. The study suggests that the target regions of thallium in the brain include the cortex, the cerebellum and the brainstem. The dose-response relationships, found for certain pairs of behavioral acts, were correlated with biochemical changes in one or more brain regions.

Evaluating and Optimizing Dentato-Rubro-Thalamic-Tract Deterministic Tractography in Deep Brain Stimulation for Essential Tremor

2021 ◽  
Author(s):  
Maarten Bot ◽  
Anne-Fleur van Rootselaari ◽  
Vincent Odekerken ◽  
Joke Dijk ◽  
Rob M A de Bie ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Essential Tremor ◽  
Brain Stimulation ◽  
Red Nucleus ◽  
Brain Regions ◽  
Superior Cerebellar Peduncle ◽  
Beneficial Effects ◽  
Ventral Intermediate Nucleus ◽  
Cerebellar Peduncle ◽  
Deep Brain

Abstract BACKGROUND Dentato-rubro-thalamic tract (DRT) deep brain stimulation (DBS) suppresses tremor in essential tremor (ET) patients. However, DRT depiction through tractography can vary depending on the included brain regions. Moreover, it is unclear which section of the DRT is optimal for DBS. OBJECTIVE To evaluate deterministic DRT tractography and tremor control in DBS for ET. METHODS After DBS surgery, DRT tractography was conducted in 37 trajectories (20 ET patients). Per trajectory, 5 different DRT depictions with various regions of interest (ROI) were constructed. Comparison resulted in a DRT depiction with highest correspondence to intraoperative tremor control. This DRT depiction was subsequently used for evaluation of short-term postoperative adverse and beneficial effects. RESULTS Postoperative optimized DRT tractography employing the ROI motor cortex, posterior subthalamic area (PSA), and ipsilateral superior cerebellar peduncle and dentate nucleus best corresponded with intraoperative trajectories (92%) and active DBS contacts (93%) showing optimal tremor control. DRT tractography employing a red nucleus or ventral intermediate nucleus of the thalamus (VIM) ROI often resulted in a more medial course. Optimal stimulation was located in the section between VIM and PSA. CONCLUSION This optimized deterministic DRT tractography strongly correlates with optimal tremor control. This technique is readily implementable for prospective evaluation in DBS target planning for ET.

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