scholarly journals Photochemically Induced Cortical Infarction in the Rat. 2. Acute and Subacute Alterations in Local Glucose Utilization

1986 ◽  
Vol 6 (2) ◽  
pp. 195-202 ◽  
Author(s):  
W. Dalton Dietrich ◽  
Myron D. Ginsberg ◽  
Raul Busto ◽  
Brant D. Watson
Keyword(s):  
Glucose Utilization ◽  
Brain Structures ◽  
Brain Regions ◽  
Metabolic Effects ◽  
Pathological Examination ◽  
Cortical Region ◽  
Irreversible Damage ◽  
Cortical Infarction ◽  
Auditory Cortices ◽  
Focal Injury

Local CMRglu (LCMRglu) values were measured by [14C]2-deoxyglucose autoradiography in the rat at 4 h and 5 days following photochemically induced cortical infarction, and these data were compared with neuropathological findings in adjacent serial sections. At both time periods, LCMRglu was markedly reduced within the lesion center, and irregular regions of moderate-to-marked glucose hypermetabolism were noted within the marginal zone of the developing infarct. At 4 h, the hypermetabolic zones were shown by pathological examination to be characterized by normal-sized, moderately hyperchromatic neurons scattered among occasional dark, shrunken neurons within preserved neuropil. In contrast, the hypermetabolic zones at 5 days coincided with foci of intense macrophage infiltration, with dissolution of the neuropil. Significant decreases in glucose utilization were also demonstrated at 4 h within brain structures remote from the site of focal injury. These structures included the lateral and auditory cortices ipsilaterally, the striatum and thalamus ipsilaterally, and the hippocampus bilaterally. In addition to these remote metabolic effects, depressed metabolism occurred within the homologous cortical region contralateral to the site of infarction. By 5 days, glucose utilization was severely depressed in all ipsilateral cortical regions but not within any contralateral cortical region. Analysis of these data suggests that more than one mechanism is responsible for the metabolic alterations occurring within brain regions remote from the site of irreversible damage. Results are discussed in light of the hemodynamic alterations occurring in this stroke model, which are presented in the accompanying report.

scholarly journals Development and Plasticity of Intra- and Intersensory Information Processing

2008 ◽  
Vol 19 (10) ◽  
pp. 780-798 ◽  
Author(s):  
Daniel B. Polley ◽  
Andrea R. Hillock ◽  
Christopher Spankovich ◽  
Maria V. Popescu ◽  
David W. Royal ◽  
...  
Keyword(s):  
Information Processing ◽  
Visual Information ◽  
Functional Organization ◽  
Brain Plasticity ◽  
Brain Structures ◽  
Brain Regions ◽  
Cortical Region ◽  
Anterior Ectosylvian Sulcus ◽  
Stable Mode ◽  
Competing Demands

The functional architecture of sensory brain regions reflects an ingenious biological solution to the competing demands of a continually changing sensory environment. While they are malleable, they have the constancy necessary to support a stable sensory percept. How does the functional organization of sensory brain regions contend with these antithetical demands? Here we describe the functional organization of auditory and multisensory (i.e., auditory-visual) information processing in three sensory brain structures: (1) a low-level unisensory cortical region, the primary auditory cortex (A1); (2) a higher-order multisensory cortical region, the anterior ectosylvian sulcus (AES); and (3) a multisensory subcortical structure, the superior colliculus (SC). We then present a body of work that characterizes the ontogenic expression of experience-dependent influences on the operations performed by the functional circuits contained within these regions. We will present data to support the hypothesis that the competing demands for plasticity and stability are addressed through a developmental transition in operational properties of functional circuits from an initially labile mode in the early stages of postnatal development to a more stable mode in the mature brain that retains the capacity for plasticity under specific experiential conditions. Finally, we discuss parallels between the central tenets of functional organization and plasticity of sensory brain structures drawn from animal studies and a growing literature on human brain plasticity and the potential applicability of these principles to the audiology clinic.

Local Coupling of Cerebral Blood Flow to Cerebral Glucose Metabolism during Inhalational Anesthesia in Rats 

1999 ◽  
Vol 91 (6) ◽  
pp. 1720-1720 ◽  
Author(s):  
Christian Lenz ◽  
Thomas Frietsch ◽  
Carsten Fütterer ◽  
Annette Rebel ◽  
Klaus van Ackern ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Glucose Utilization ◽  
Brain Structures ◽  
Volatile Anesthetics ◽  
Brain Regions ◽  
Local Analysis ◽  
Sprague Dawley ◽  
Mean Values ◽  
Cerebral Glucose Utilization

Background It is not known whether the effects of desflurane on local cerebral glucose utilization (LCGU) and local cerebral blood flow (LCBF) are different from those of other volatile anesthetics. Methods Using the autoradiographic iodoantipyrine and deoxyglucose methods, LCGU, LCBF, and their overall means were measured in 60 Sprague-Dawley rats (10 groups, n = 6 each) during desflurane and isoflurane anesthesia and in conscious controls. Results During anesthesia, mean cerebral glucose utilization was decreased compared with conscious controls: 1 minimum alveolar concentration (MAC) desflurane: -52%; 1 MAC isoflurane: -44%; 2 MAC desflurane: -62%; and 2 MAC isoflurane: -60%. Local analysis showed a reduction of LCGU in the majority of the 40 brain regions analyzed. Mean cerebral blood flow was increased: 1 MAC desflurane: +40%; 1 MAC isoflurane: +43%; 2 MAC desflurane and 2 MAC isoflurane: +70%. LCBF was increased in all brain structures investigated except in the auditory cortex. No significant differences (P < 0.05) could be observed between both anesthetics for mean values of cerebral glucose use and blood flow. Correlation coefficients obtained for the relation between LCGU and LCBF were as follows: controls: 0.95; 1 MAC desflurane: 0.89; 2 MAC desflurane: 0.60; 1 MAC isoflurane: 0.87; and 2 MAC isoflurane: 0.68. Conclusion Differences in the physicochemical properties of desflurane compared with isoflurane are not associated with major differences in the effects of both volatile anesthetics on cerebral glucose utilization, blood flow, and the coupling between LCBF and LCGU.

scholarly journals Photochemically Induced Cortical Infarction in the Rat. 1. Time Course of Hemodynamic Consequences

1986 ◽  
Vol 6 (2) ◽  
pp. 184-194 ◽  
Author(s):  
W. Dalton Dietrich ◽  
Myron D. Ginsberg ◽  
Raul Busto ◽  
Brant D. Watson
Keyword(s):  
Time Course ◽  
Green Light ◽  
Brain Structures ◽  
Brain Regions ◽  
Repeated Measurements ◽  
Consistent Pattern ◽  
Subcortical Structures ◽  
Systemic Injection ◽  
Cortical Infarction ◽  
Cortical Regions

Alterations in local CBF (LCBF) were assessed autoradiographically in the rat at several time points following photochemically induced cortical infarction. Cortical infarction of consistent size and location was produced by irradiating the brain with green light through the intact skull for 20 min following the systemic injection of rose bengal. A consistent pattern of altered LCBF was recorded in both ipsilateral and contralateral brain regions over the course of the study. At 30 min, a severely ischemic zone surrounded by regions of cortical hyperemia was apparent. LCBF was also depressed relative to control values in ipsilateral cortical regions remote from the irradiated area, while contralateral cortical structures were mildly hyperemic. By 4 h, the zone of severe ischemia had enlarged and its margins were no longer hyperemic. Ipsilateral cortical and some subcortical structures demonstrated significantly depressed levels of LCBF. At 5 days, LCBF throughout both ipsilateral and contralateral cortices was depressed compared with control values. By 15 days, LCBF had returned to control levels in most brain structures shown histopathologically not to be irreversibly damaged. The temporal sequence and magnitude of these hemodynamic alterations are consistent with findings in clinical studies in which repeated measurements of CBF have been carried out in patients with acute stroke. The ability to produce a cortical infarct that results in a consistent pattern of altered CBF should facilitate the investigation of stroke mechanisms responsible for these hemodynamic abnormalities.

scholarly journals Prolonged Effects of Cholinesterase Inhibition with Eptastigmine on the Cerebral Blood Flow-Metabolism Ratio of Normal Rats

1993 ◽  
Vol 13 (4) ◽  
pp. 702-711 ◽  
Author(s):  
Oscar U. Scremin ◽  
A. M. Erika Scremin ◽  
Deborah Heuser ◽  
Raymond Hudgell ◽  
Elsa Romero ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Glucose Utilization ◽  
Regression Line ◽  
Brain Regions ◽  
Metabolic Effects ◽  
Cholinesterase Inhibition ◽  
Arterial Blood ◽  
A Value ◽  
Similar Dose

The cerebrovascular and metabolic effects of the novel cholinesterase inhibitor eptastigmine were tested in conscious rats. The drug was administered by single intravenous injection, and blood flow or glucose utilization were assessed in 38 brain regions by quantitative autoradiographic techniques. A dose-dependent increase in regional cerebral blood flow (rCBF) was obtained for i.v. doses ranging from 0.5 to 3 mg kg−1. Forty minutes after the dose of 1.5 mg kg−1, average rCBF of the 38 regions studied was (mean ± SD) 2.62 ± 0.62 ml g−1 min−1, a value significantly higher than that of saline-injected controls (1.46 ± 0.26; p < 0.005). In contrast, a similar dose of eptastigmine did not significantly alter regional cerebral glucose utilization (rCGU) (0.90 ± 0.21 μmol g−1 min−1) when compared with saline-injected controls (0.99 ± 0.08 μmol g−1 min−1). A linear correlation between rCBF and rCGU was observed both in saline ( r = 0.871) and eptastigmine ( r = 0.873)-injected animals but the slope of the regression line of rCBF on rCGU was significantly higher (p < 0.01) in the eptastigmine group (2.863 ± 0.266) than in the controls that received saline (1.00 ± 0.094). The cerebral vasodilatation induced by eptastigmine peaked at 40 min after drug administration. No toxic signs were observed at the doses used. Mean arterial blood pressure decreased after 0.5 mg kg−1 (control = 109.3 ± 10.56 mm Hg; eptastigmine = 96.6 ± 8.10 mm Hg) but did not differ from control at the higher doses. It is concluded that eptastigmine induces a long-lasting increase in rCBF and a significant enhancement of the rCBF:rCGU ratio in most regions. The results suggest an important role of endogenous acetylcholine in the control of cerebral perfusion.

Effects of Xenon on Cerebral Blood Flow and Cerebral Glucose Utilization in Rats

2001 ◽  
Vol 94 (2) ◽  
pp. 290-297 ◽  
Author(s):  
Thomas Frietsch ◽  
Ralph Bogdanski ◽  
Manfred Blobner ◽  
Christian Werner ◽  
Wolfgang Kuschinsky ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Steady State ◽  
Glucose Utilization ◽  
Brain Structures ◽  
Brain Regions ◽  
Local Cerebral Blood Flow ◽  
Mean Values ◽  
Cerebral Glucose Utilization ◽  
Local Brain

Background The effects of xenon inhalation on mean and local cerebral blood flow (CBF) and mean and local cerebral glucose utilization (CGU) were investigated using iodo-[14C]antipyrine and [14C]deoxyglucose autoradiography. Methods Rats were randomly assigned to the following groups: conscious controls (n = 12); 30% (n = 12) or 70% xenon (n = 12) for 45 min for the measurement of local CBF and CGU; or 70% xenon for 2 min (n = 6) or 5 min (n = 6) for the measurement of local CBF only. Results Compared with conscious controls, steady state inhalation of 30 or 70% xenon did not result in changes of either local or mean CBF. However, mean CBF increased by 48 and 37% after 2 and 5 min of 70% xenon short inhalation, which was entirely caused by an increased local CBF in cortical brain regions. Mean CGU determined during steady state 30 or 70% xenon inhalation remained unchanged, although local CGU decreased in 7 (30% xenon) and 18 (70% xenon) of the 40 examined brain regions. The correlation between CBF and CGU in 40 local brain structures was maintained during steady state inhalation of both 30 and 70% xenon inhalation, although at an increased slope at 70% xenon. Conclusion Effects of 70% xenon inhalation on CBF in rats are time-dependent. During steady state xenon inhalation (45 min), mean values of CBF and CGU do not differ from control values, and the relation of regional CBF to CGU is maintained, although reset at a higher level.

scholarly journals Distribution of Glut1 Glucose Transporters in Different Brain Structures Compared to Glucose Utilization and Capillary Density of Adult Rat Brains

1997 ◽  
Vol 17 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Karin Zeller ◽  
Sylvia Rahner-Welsch ◽  
Wolfgang Kuschinsky
Keyword(s):  
Glucose Utilization ◽  
Brain Structures ◽  
Capillary Density ◽  
Brain Regions ◽  
Capillary Endothelium ◽  
Tight Coupling ◽  
Adult Rats ◽  
Heterogeneous Distribution ◽  
Adult Rat ◽  
The Brain

Glut1 is a specific transporter system that mediates glucose transfer across the blood–brain barrier (BBB). Although the main location of Glut1 is in the capillary endothelium of the brain, its local distribution in different brain regions is not as well defined. In the present investigation, the local pattern of Glut1 distribution was determined in 13 brain structures using an immunoautoradiographic method developed for this purpose. A polyclonal antibody directed against the C-terminal amino acid sequence of Glut1 was applied to cryosections of rat brains. A secondary antibody was added that had been coupled to [35S]. Results show a heterogeneous distribution of Glut1 in the brain with activities of [35S] ranging from 65% below to 15% above the mean. White matter activity was lower than gray matter activity. For comparison, capillary sections were counted in corresponding cryosections by indirect immunofluorescence using fibronectin antibodies. In addition, local cerebral glucose utilization (LCGU) was analyzed in identical brain structures of conscious rats by the quantitative autoradiographic 2-deoxyglucose method. Significant correlations were found between Glut1 density and either LCGU or capillary density. Results indicate a tight coupling of Glut1 transporter density and capillary density to the LCGU of different BBB structures in adult rats.

scholarly journals Dissociable Mechanisms of Verbal Working Memory Revealed through Multivariate Lesion Mapping

2019 ◽  
Vol 30 (4) ◽  
pp. 2542-2554 ◽  
Author(s):  
Maryam Ghaleh ◽  
Elizabeth H Lacey ◽  
Mackenzie E Fama ◽  
Zainab Anbari ◽  
Andrew T DeMarco ◽  
...  
Keyword(s):  
Working Memory ◽  
Spatial Working Memory ◽  
Superior Temporal Gyrus ◽  
Verbal Working Memory ◽  
Brain Structures ◽  
Brain Regions ◽  
Task Demands ◽  
Auditory Information ◽  
Verbal Information ◽  
Task Conditions

Abstract Two maintenance mechanisms with separate neural systems have been suggested for verbal working memory: articulatory-rehearsal and non-articulatory maintenance. Although lesion data would be key to understanding the essential neural substrates of these systems, there is little evidence from lesion studies that the two proposed mechanisms crucially rely on different neuroanatomical substrates. We examined 39 healthy adults and 71 individuals with chronic left-hemisphere stroke to determine if verbal working memory tasks with varying demands would rely on dissociable brain structures. Multivariate lesion–symptom mapping was used to identify the brain regions involved in each task, controlling for spatial working memory scores. Maintenance of verbal information relied on distinct brain regions depending on task demands: sensorimotor cortex under higher demands and superior temporal gyrus (STG) under lower demands. Inferior parietal cortex and posterior STG were involved under both low and high demands. These results suggest that maintenance of auditory information preferentially relies on auditory-phonological storage in the STG via a nonarticulatory maintenance when demands are low. Under higher demands, sensorimotor regions are crucial for the articulatory rehearsal process, which reduces the reliance on STG for maintenance. Lesions to either of these regions impair maintenance of verbal information preferentially under the appropriate task conditions.

Sleep Duration, Sleep Apnea, and Gray Matter Volume

2021 ◽  
pp. 089198872098891
Author(s):  
Regina Eun Young Kim ◽  
Robert Douglas Abbott ◽  
Soriul Kim ◽  
Robert Joseph Thomas ◽  
Chang-Ho Yun ◽  
...  
Keyword(s):  
Sleep Apnea ◽  
Sleep Duration ◽  
Gray Matter ◽  
Gray Matter Volume ◽  
Brain Structures ◽  
Brain Regions ◽  
Population Based ◽  
Older Individuals ◽  
Bootstrap Sampling ◽  
Matter Volume

This study aimed to evaluate the effect of sleep duration on brain structures in the presence versus absence of sleep apnea in middle-aged and older individuals. The study investigated a population-based sample of 2,560 individuals, aged 49-80 years. The presence of sleep apnea and self-reported sleep duration were examined in relation to gray matter volume (GMV) in total and lobar brain regions. We identified ranges of sleep duration associated with maximal GMV using quadratic regression and bootstrap sampling. A significant quadratic association between sleep duration and GMV was observed in total and lobar brain regions of men with sleep apnea. In the fully adjusted model, optimal sleep durations associated with peak GMV between brain regions ranged from 6.7 to 7.0 hours. Shorter and longer sleep durations were associated with lower GMV in total and 4 sub-regions of the brain in men with sleep apnea.

Intranasal administration of mitochondria improves spatial memory in olfactory bulbectomized mice

2021 ◽  
pp. 153537022110568
Author(s):  
Natalia V Bobkova ◽  
Daria Y Zhdanova ◽  
Natalia V Belosludtseva ◽  
Nikita V Penkov ◽  
Galina D Mironova
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Spatial Memory ◽  
Intranasal Administration ◽  
Brain Structures ◽  
Brain Regions ◽  
Dependent Manner ◽  
Behavioral Experiments ◽  
Hippocampal Cell Culture ◽  
The Brain

Here, we found that functionally active mitochondria isolated from the brain of NMRI donor mice and administrated intranasally to recipient mice penetrated the brain structures in a dose-dependent manner. The injected mitochondria labeled with the MitoTracker Red localized in different brain regions, including the neocortex and hippocampus, which are responsible for memory and affected by degeneration in patients with Alzheimer's disease. In behavioral experiments, intranasal microinjections of brain mitochondria of native NMRI mice improved spatial memory in the olfactory bulbectomized (OBX) mice with Alzheimer’s type degeneration. Control OBX mice demonstrated loss of spatial memory tested in the Morris water maze. Immunocytochemical analysis revealed that allogeneic mitochondria colocalized with the markers of astrocytes and neurons in hippocampal cell culture. The results suggest that a non-invasive route intranasal administration of mitochondria may be a promising approach to the treatment of neurodegenerative diseases characterized, like Alzheimer's disease, by mitochondrial dysfunction.

scholarly journals Multi-scale analysis of schizophrenia risk genes, brain structure, and clinical symptoms reveals integrative clues for subtyping schizophrenia patients

2018 ◽  
Vol 11 (8) ◽  
pp. 678-687
Author(s):  
Liang Ma ◽  
Edmund T Rolls ◽  
Xiuqin Liu ◽  
Yuting Liu ◽  
Zeyu Jiao ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Brain Structures ◽  
Brain Regions ◽  
First Episode ◽  
Grey Matter Volume ◽  
Scale Analysis ◽  
Risk Genes ◽  
Multi Scale ◽  
Scale Scores ◽  
Multi Scale Analysis

AbstractAnalysis linking directly genomics, neuroimaging phenotypes and clinical measurements is crucial for understanding psychiatric disorders, but remains rare. Here, we describe a multi-scale analysis using genome-wide SNPs, gene expression, grey matter volume (GMV), and the positive and negative syndrome scale scores (PANSS) to explore the etiology of schizophrenia. With 72 drug-naive schizophrenic first episode patients (FEPs) and 73 matched heathy controls, we identified 108 genes, from schizophrenia risk genes, that correlated significantly with GMV, which are highly co-expressed in the brain during development. Among these 108 candidates, 19 distinct genes were found associated with 16 brain regions referred to as hot clusters (HCs), primarily in the frontal cortex, sensory-motor regions and temporal and parietal regions. The patients were subtyped into three groups with distinguishable PANSS scores by the GMV of the identified HCs. Furthermore, we found that HCs with common GMV among patient groups are related to genes that mostly mapped to pathways relevant to neural signaling, which are associated with the risk for schizophrenia. Our results provide an integrated view of how genetic variants may affect brain structures that lead to distinct disease phenotypes. The method of multi-scale analysis that was described in this research, may help to advance the understanding of the etiology of schizophrenia.

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