RESUMEN
This functional magnetic resonance imaging study compared the neural activation patterns of 18 high-functioning individuals with autism and 18 IQ-matched neurotypical control participants as they learned to perform a social judgment task. Participants learned to identify liars among pairs of computer-animated avatars uttering the same sentence but with different facial and vocal expressions, namely those that have previously been associated with lying versus truth-telling. Despite showing a behavioral learning effect similar to the control group, the autism group did not show the same pattern of decreased activation in cortical association areas as they learned the task. Furthermore, the autism group showed a significantly smaller increase in interregion synchronization of activation (functional connectivity) with learning than did the control group. Finally, the autism group had decreased structural connectivity as measured by corpus callosum size, and this measure was reliably related to functional connectivity measures. The findings suggest that cortical underconnectivity in autism may constrain the ability of the brain to rapidly adapt during learning.
Asunto(s)
Aprendizaje por Asociación/fisiología , Trastorno Autístico/patología , Trastorno Autístico/fisiopatología , Mapeo Encefálico , Corteza Cerebral/fisiopatología , Conducta Social , Estimulación Acústica , Adolescente , Adulto , Análisis de Varianza , Estudios de Casos y Controles , Corteza Cerebral/irrigación sanguínea , Cuerpo Calloso/irrigación sanguínea , Cuerpo Calloso/patología , Cuerpo Calloso/fisiopatología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Vías Nerviosas/irrigación sanguínea , Vías Nerviosas/fisiopatología , Oxígeno/sangre , Tiempo de Reacción , Adulto JovenRESUMEN
Cerebral white matter lesions (WMLs) are frequently observed in vascular dementia and Alzheimer's disease and are believed to be responsible for cognitive dysfunction. The cerebral WMLs are most likely caused by chronic cerebral hypoperfusion and can be experimentally induced by permanent bilateral common carotid artery occlusion (BCCAO) in rats. Previous studies found the involvement of oxidative stress and astrocytic activation in the cerebral WMLs of BCCAO rats. Gypenoside (GP), a pure component extracted from the Gyrostemma pentaphyllum Makino, a widely reputed medicinal plants in China, has been reported to have some neuroprotective effects via anti-oxidative stress and anti-inflammatory mechanisms. In the present study, we investigated the protective effect of GP against cerebral WMLs and the underlying mechanisms for its inhibition of cognitive decline in BCCAO rats. Adult male Sprague-Dawley rats were orally administered daily doses of 200 and 400mg/kg GP for 33 days after BCCAO, and spatial learning and memory were assessed using the Morris water maze. Following behavioral testing, oxygen free radical levels and antioxidative capability were measured biochemically. The levels of lipid peroxidation and oxidative DNA damage were also assessed by immunohistochemical staining for 4-hydroxynonenal and 8-hydroxy-2'-deoxyguanosine, respectively. Activated astrocytes were also assessed by immunohistochemical staining and Western blotting with GFAP antibodies. The morphological changes were stained with Klüver-Barrera. Rats receiving 400mg/kg GP per day performed significantly better in tests for spatial learning and memory than saline-treated rats. GP 400mg/kg per day were found to markedly scavenge oxygen free radicals, enhance antioxidant abilities, decrease lipid peroxide production and oxidative DNA damage, and inhibit the astrocytic activation in corpus callosum and optic tract in BCCAO rats. However, GP 200mg/kg per day had no significant effects. GP may have therapeutic potential for treating dementia induced by chronic cerebral hypoperfusion and further evaluation is warranted.
Asunto(s)
Trastornos Cerebrovasculares/patología , Trastornos Cerebrovasculares/prevención & control , Cuerpo Calloso/patología , Vías Visuales/patología , Animales , Enfermedad Crónica , Cuerpo Calloso/irrigación sanguínea , Cuerpo Calloso/efectos de los fármacos , Gynostemma , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Aprendizaje por Laberinto/fisiología , Fibras Nerviosas Mielínicas/efectos de los fármacos , Fibras Nerviosas Mielínicas/patología , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Ratas , Ratas Sprague-Dawley , Conducta Espacial/efectos de los fármacos , Conducta Espacial/fisiología , Vías Visuales/irrigación sanguínea , Vías Visuales/efectos de los fármacosRESUMEN
Neuroimaging studies show that permanent peripheral lesions such as unilateral deafness cause functional reorganization in the auditory pathways. However, functional reorganization of the auditory pathways as a result of higher-level damage or abnormalities remains poorly investigated. A relatively recent behavioural study points to functional changes in the auditory pathways in some, but interestingly not in all, of the acallosal individuals that were tested. The present study uses fMRI to investigate auditory activities in both cerebral hemispheres in those same acallosal subjects in order to directly investigate the contributions of ipsilateral and contralateral functional pathways reorganization. Predictions were made that functional reorganization could be predicted from behavioural performance. As reported previously in a number of neuroimaging studies, results showed that in neurologically intact subjects, binaural stimulation induced balanced activities between both hemispheres, while monaural stimulation induced strong contralateral activities and weak ipsilateral activities. In accordance with behavioural predictions, some acallosal subjects showed patterns of auditory cortical activities that were similar to those observed in neurologically intact subjects while others showed functional reorganization of the auditory pathways. Essentially they showed a significant increase and a significant decrease of neural activities in the contralateral and/or ipsilateral pathways, respectively. These findings indicate that at least in some acallosal subjects, functional reorganization inside the auditory pathways does contribute to compensate for the absence of the corpus callosum.
Asunto(s)
Agenesia del Cuerpo Calloso , Cuerpo Calloso/fisiopatología , Lateralidad Funcional/fisiología , Localización de Sonidos/fisiología , Lóbulo Temporal/patología , Estimulación Acústica/métodos , Adulto , Vías Auditivas/anomalías , Vías Auditivas/irrigación sanguínea , Vías Auditivas/patología , Mapeo Encefálico , Estudios de Casos y Controles , Cuerpo Calloso/irrigación sanguínea , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Lóbulo Temporal/fisiopatologíaRESUMEN
We report the first known case of anorexia nervosa (AN) with Marchiafava-Bignami Disease (MBD) that responded to high-dose intravenous corticosteroid administration. A 16-year-old Japanese female with AN was diagnosed with MBD after rapid weight loss. During the acute stage, she suffered from a sudden onset of coma. After regaining consciousness, she presented with lack of movement, apathy, labile affect, and poverty of speech. On admission, magnetic resonance imaging showed an area of demyelination in the splenium of the corpus callosum. Positron emission tomography obtained 7 days after admission showed areas of hypoperfusion in the medial temporal lobe and in regions anterior and posterior to the central sulcus.
Asunto(s)
Anorexia Nerviosa/complicaciones , Fursultiamina/administración & dosificación , Enfermedad de Marchiafava-Bignami/tratamiento farmacológico , Metilprednisolona/administración & dosificación , Fármacos Neuroprotectores/administración & dosificación , Complejo Vitamínico B/administración & dosificación , Adolescente , Anorexia Nerviosa/tratamiento farmacológico , Cuerpo Calloso/irrigación sanguínea , Cuerpo Calloso/efectos de los fármacos , Cuerpo Calloso/patología , Relación Dosis-Respuesta a Droga , Femenino , Lóbulo Frontal/irrigación sanguínea , Lóbulo Frontal/efectos de los fármacos , Lóbulo Frontal/patología , Escala de Coma de Glasgow , Humanos , Infusiones Intravenosas , Imagen por Resonancia Magnética , Enfermedad de Marchiafava-Bignami/diagnóstico , Enfermedad de Marchiafava-Bignami/psicología , Examen Neurológico/efectos de los fármacos , Tomografía de Emisión de Positrones , Flujo Sanguíneo Regional/efectos de los fármacos , Lóbulo Temporal/irrigación sanguínea , Lóbulo Temporal/efectos de los fármacos , Lóbulo Temporal/patologíaRESUMEN
OBJECTIVE: To investigate patients with posterior cerebral artery (PCA) infarctions to learn whether hemispatial neglect is more frequent and severe after right than left PCA infarction; whether visual field defects (VFDs) influence the presence or severity of hemispatial neglect; and the anatomic loci of lesions that are associated with hemispatial neglect. METHODS: The authors recruited 45 patients with PCA infarction that involved only the occipital lobe or the occipital lobe plus other areas served by the PCA. All subjects received seven neglect tests within 2 months after onset. RESULTS: Overall, the frequency of hemispatial neglect was 42.2%. The frequency did not significantly differ between the right (48.0%) and left (35.0%) PCA groups, but the severity of hemispatial neglect was significantly greater in the right group. VFD alone did not influence the frequency or severity of neglect after controlling other variables. Isolated occipital lesions were rarely associated with hemispatial neglect, and it was only the occipital plus splenial lesion that significantly influenced the frequency and severity of neglect. CONCLUSIONS: This study suggests that after excluding such confounding factors as aphasia or hemiplegia, neglect frequency does not differ between the right and left posterior cerebral artery (PCA) groups, but the severity of neglect is greater after right PCA infarctions; even in the acute stage of PCA infarction; visual field defect from an isolated occipital lesion does not cause hemispatial neglect; and the injury to both the occipital lobe and the splenium of the corpus callosum is important for producing hemispatial neglect with PCA infarction.
Asunto(s)
Infarto Encefálico/diagnóstico , Lateralidad Funcional/fisiología , Lóbulo Occipital/patología , Lóbulo Occipital/fisiopatología , Trastornos de la Percepción/diagnóstico , Arteria Cerebral Posterior/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Infarto Encefálico/fisiopatología , Infarto Cerebral/diagnóstico , Infarto Cerebral/fisiopatología , Cuerpo Calloso/irrigación sanguínea , Cuerpo Calloso/patología , Cuerpo Calloso/fisiopatología , Femenino , Hemianopsia/diagnóstico , Hemianopsia/etiología , Hemianopsia/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Lóbulo Occipital/irrigación sanguínea , Trastornos de la Percepción/etiología , Trastornos de la Percepción/fisiopatología , Arteria Cerebral Posterior/patología , Valor Predictivo de las Pruebas , Percepción Espacial/fisiología , Lóbulo Temporal/irrigación sanguínea , Lóbulo Temporal/patología , Lóbulo Temporal/fisiopatología , Tálamo/irrigación sanguínea , Tálamo/patología , Tálamo/fisiopatología , Corteza Visual/irrigación sanguínea , Corteza Visual/patología , Corteza Visual/fisiopatología , Campos Visuales/fisiología , Vías Visuales/irrigación sanguínea , Vías Visuales/patología , Vías Visuales/fisiopatología , Percepción Visual/fisiologíaRESUMEN
Clinical-neuropsychological investigations were performed in 187 patients with arteriovenous malformations (AVM) of deep brain structures; 28 had AVM of the caudate nucleus, 35 of the thalamus, 45 of the cingulate gyrus, 43 of the hippocampus, and 36 of the corpus callosum. A total of 47 patients displayed neglect phenomena of different modalities, while unfixed neglect was demonstrated in 40 cases using special tests. The vast majority of patients showed neglect of left-sided space and the left side of the body, while only three patients showed right-sided neglect. These three patients had signs of left-handedness. In the development of neglect in all patients was associated with post-hemorrhagic or post-operative damage to the white matter (the projections of sensory bundles of the parietal and occipital lobes, the periventricular white matter) or the thalamus and corpus callosum. In hemispheric lesions, neglect developed on the background of the corresponding derangements (hemihypesthesia hemianopsia) and were of the same modality. In cases of damage to the corpus callosum, neglect could develop without accompanying sensory disturbances or the phenomenon could occur on different sides (in cases of simultaneous left hemisphere damage). This supports the independent nature of the neglect phenomenon.
Asunto(s)
Encéfalo/patología , Malformaciones Arteriovenosas Intracraneales/psicología , Trastornos de la Percepción/psicología , Núcleo Caudado/irrigación sanguínea , Núcleo Caudado/patología , Hemorragia Cerebral/patología , Hemorragia Cerebral/psicología , Circulación Cerebrovascular/fisiología , Cuerpo Calloso/irrigación sanguínea , Cuerpo Calloso/patología , Lateralidad Funcional/fisiología , Giro del Cíngulo/irrigación sanguínea , Giro del Cíngulo/patología , Hipocampo/irrigación sanguínea , Hipocampo/patología , Humanos , Malformaciones Arteriovenosas Intracraneales/etiología , Malformaciones Arteriovenosas Intracraneales/patología , Trastornos de la Memoria/etiología , Trastornos de la Memoria/psicología , Pruebas Neuropsicológicas , Trastornos de la Percepción/etiología , Trastornos de la Percepción/patología , Tálamo/irrigación sanguínea , Tálamo/patologíaRESUMEN
PURPOSE: The purpose of this work was to describe the deep vascular anatomy of the human brain using high resolution MR gradient echo imaging at 8 T. METHOD: Gradient echo images were acquired from the human head using a transverse electromagnetic resonator operating in quadrature and tuned to 340 MHz. Typical acquisition parameters were as follows: matrix = 1,024 x 1,024, flip angle = 45 degrees, TR = 750 ms, TE = 17 ms, FOV = 20 cm, slice thickness = 2 mm. This resulted in an in-plane resolution of approximately 200 microm. Images were analyzed, and vascular structures were identified on the basis of location and course. RESULTS: High resolution ultra high field magnetic resonance imaging (UHFMRI) enabled the visualization of many small vessels deep within the brain. These vessels were typically detected as signal voids, and the majority represented veins. The prevalence of the venous vasculature was attributed largely to the magnetic susceptibility of deoxyhemoglobin. It was possible to identify venous structures expected to measure below 100 microm in size. Perforating venous drainage within the deep gray structures was identified along with their parent vessels. The course of arterial perforators was more difficult to follow and not as readily identified as their venous counterparts. CONCLUSION: The application of high resolution gradient echo methods in UHFMRI provides a unique detailed view of particularly the deep venous vasculature of the human brain.
Asunto(s)
Artefactos , Encéfalo/irrigación sanguínea , Venas Cerebrales/anatomía & histología , Aumento de la Imagen/métodos , Imagen por Resonancia Magnética/métodos , Arterias/anatomía & histología , Núcleo Caudado/irrigación sanguínea , Ventrículos Cerebrales/irrigación sanguínea , Plexo Coroideo/irrigación sanguínea , Cuerpo Calloso/irrigación sanguínea , Cuerpo Estriado/irrigación sanguínea , Fenómenos Electromagnéticos/instrumentación , Espectroscopía de Resonancia por Spin del Electrón , Hemoglobinas , Humanos , Procesamiento de Imagen Asistido por Computador , Prevalencia , Tálamo/irrigación sanguíneaRESUMEN
The deep venous system is best defined as the entire territory served by the great vein of Galen and the basal veins. This comprises not only the choroid plexuses and the deep grey matter of the thalamus and striatum, but also the periventricular white matter and corpus callosum, hippocampus and the cortical areas of the limbic lobe including the cingulate and parahippocampal gyri, the visual cortex, the diencephalon and rostral brain stem, and part of the cerebellum. The superficial venous system comprises the remaining neocortex (with the cortex of the entire convexity) together with a layer of subcortical white matter, separated from the periventricular white matter by a venous watershed. Outflow towards the great vein of Galen and straight sinus can be substituted by collateral channels towards the basal vein. The basal vein in turn is connected not only to the great vein of Galen, but also to the superior petrosal sinus (via the lateral mesencephalic vein), and in the adult configuration to the cavernous sinus and pterygoid plexus (via the deep and superficial sylvian veins). Evidence from pathological anatomy indicates that the venous watershed exists not only in the white matter of the hemispheres, but between the entire territories of the deep and superficial venous systems. Because of their anastomotic interconnections, only simultaneous obstruction of veins of Galen and basal veins wil effectively obstruct deep venous outflow. This can occur in the tentorial incisura, from swelling or displacement of the midbrain due to brain oedema, haematoma or tumour. Complete obstruction of great vein of Galen and basal veins leads to rapid death. In patients who survive incomplete obstruction, various combinations of damage to parts of the deep venous territory exist. This is possible because very many tributaries of the deep system unite below and sometimes above the tentorial incisura. The hallmarks these varying deep venous obstructions have in common are sparing of the subcortical white matter of the convexity, and cortical involvement limited to the limbic lobe and visual cortex. Obstruction of cerebral venous outflow explains many pathological phenomena. Treatment must aim at relieving this obstacle to blood flow.
Asunto(s)
Venas Cerebrales/fisiología , Circulación Cerebrovascular/fisiología , Adulto , Encefalopatías/complicaciones , Tronco Encefálico/irrigación sanguínea , Cerebelo/irrigación sanguínea , Corteza Cerebral/irrigación sanguínea , Presión del Líquido Cefalorraquídeo/fisiología , Trastornos Cerebrovasculares/etiología , Plexo Coroideo/irrigación sanguínea , Cuerpo Calloso/irrigación sanguínea , Cuerpo Estriado/irrigación sanguínea , Senos Craneales/fisiología , Hipocampo/irrigación sanguínea , Humanos , Sistema Límbico/irrigación sanguínea , Neocórtex/irrigación sanguínea , Tálamo/irrigación sanguíneaRESUMEN
The anterior communicating artery (ACoA) and its branches were examined in 22 human brains after injecting Indian ink or methylmethacrylate. The ACoA branches were divided into the small and the large. Small branches were from 1 to 5 in number (mean 2), and from 70 to 270 microns in diameter (mean 151 microns). Seventy-six percent of the branches originated directly from the ACoA. They tended to arise closer to the left than to the right anterior cerebral artery. Fourteen percent of them arose from the junctional site of the ACoA with the anterior cerebral arteries, and 10% from the site of origin of the subcallosal artery. Large branches were identified as the median artery of the corpus callosum, and the subcallosal artery, respectively. The former vessel was present in 9% of the patients, and the latter in 91%. The subcallosal artery was from 320 to 640 microns in size (mean 486 microns). It tended to arise from the middle of the ACoA. In spite of the very frequent anastomoses involving the ACoA branches, care must be taken to avoid injury to these important vessels during operations of the ACoA aneurysms.
Asunto(s)
Arterias Cerebrales/cirugía , Aneurisma Intracraneal/cirugía , Microcirugia , Adulto , Anciano , Arterias Cerebrales/patología , Cuerpo Calloso/irrigación sanguínea , Giro del Cíngulo/irrigación sanguínea , Humanos , Hipotálamo/irrigación sanguínea , Aneurisma Intracraneal/patología , Persona de Mediana EdadRESUMEN
A patient with verbal amnesia and a propensity to direct his attention to the right following a retrosplenial area lesion was studied with positron emission tomography using [F-18] fluorodeoxyglucose. These studies showed that the left thalamus was hypometabolic, and the anterior 2/3 of the left hemisphere was hypermetabolic when compared with the right. There were no significant differences seen in the medial temporal lobes. Based on this study, it is posited that interruption of hippocampal input into the anterior thalamus was responsible for the amnesia, and the left frontal hyperactivity was associated with the propensity to attend contralaterally.
Asunto(s)
Amnesia/fisiopatología , Cuerpo Calloso/irrigación sanguínea , Metabolismo Energético/fisiología , Lóbulo Frontal/fisiopatología , Malformaciones Arteriovenosas Intracraneales/cirugía , Orientación/fisiología , Complicaciones Posoperatorias/fisiopatología , Tálamo/fisiopatología , Adulto , Glucemia/metabolismo , Daño Encefálico Crónico/fisiopatología , Mapeo Encefálico , Desoxiglucosa/análogos & derivados , Desoxiglucosa/metabolismo , Fluorodesoxiglucosa F18 , Humanos , Malformaciones Arteriovenosas Intracraneales/fisiopatología , Masculino , Recuerdo Mental/fisiología , Vías Nerviosas/fisiopatología , Tomografía Computarizada de Emisión , Escalas de WechslerRESUMEN
Thirty cadaver brains were examined under X 6 to 16 magnification in order to define the microsurgical anatomy of the pineal region, particularly the relationship of the pineal body, posterior cerebral artery, superior cerebellar artery, vein of Galen, basal vein of Rosenthal, internal cerebral vein, straight sinus, bridging vein, the size of the tentorial notch, and the third and the fourth cranial nerves. The infratentorial and supratentorial approaches to the pineal region are compared from the viewpoint of microsurgical anatomy.
Asunto(s)
Glándula Pineal/cirugía , Arterias , Encéfalo/irrigación sanguínea , Cerebelo/irrigación sanguínea , Arterias Cerebrales/anatomía & histología , Plexo Coroideo/irrigación sanguínea , Cuerpo Calloso/irrigación sanguínea , Senos Craneales/anatomía & histología , Hipocampo/irrigación sanguínea , Humanos , Microcirugia , Glándula Pineal/anatomía & histología , Tálamo/irrigación sanguínea , VenasRESUMEN
The anatomy of the Anterior Communicating Artery complex is studied with the aid of the Zeiss operating microscope in 75 human brains removed at autopsy. The variations in the structure of the Anterior Communicating Artery and the A1 and A2 segments of the Anterior Cerebral Artery are reported. Special attention is given to the site of origin and number of branches from the Anterior Communicating Artery and the site of origin of Heubner's arteries. The necessity of using the operating microscope during surgical treatment of aneurysms of the Anterior Communicating Artery complex is stressed.
Asunto(s)
Arterias Cerebrales/anatomía & histología , Cuerpo Calloso/irrigación sanguínea , Humanos , Hipotálamo/irrigación sanguínea , Microcirugia/instrumentaciónRESUMEN
The authors present this study of proximal anterior cerebral arteries in the normal human to provide a clearer basis for strategy in aneurysm surgery. They describe patterns of origin of branches, their subarachnoid course, and parenchymal distribution. Branches that originate from the anterior cerebral artery at the internal carotid bifurcation perfuse the genu and contiguous posterior limb of the internal capsule and the rostral thalamus. Proximal 4-mm branches supply the anterior limb of the internal capsule, the neighboring hypothalamus, anteroventral putamen, and pallidum. The remaining anterior cerebral artery proximal to the communicating artery sends branches to the optic chiasm, the adjacent hypothalamus, and the anterior commissure. Heubner's artery arises directly opposite the anterior communicating artery to supply much of the striatum and internal capsule rostral to the anterior commissure. The anterior communicating artery branches supply the fornix, corpus callosum, septal region, and anterior cingulum. The parenchymal distribution of these end arteries may be surmised from the site of origin named vessels. With this anatomical information one can avoid interruption of blood supply to vital structures when dealing with the anterior cerebral artery and its branches.
Asunto(s)
Arterias Cerebrales/anatomía & histología , Adulto , Anciano , Núcleo Caudado/irrigación sanguínea , Círculo Arterial Cerebral/anatomía & histología , Cuerpo Calloso/irrigación sanguínea , Cuerpo Estriado/irrigación sanguínea , Humanos , Hipotálamo/irrigación sanguínea , Aneurisma Intracraneal/cirugía , Métodos , Persona de Mediana Edad , Quiasma Óptico/irrigación sanguínea , Nervio Óptico/irrigación sanguínea , Tabique Pelúcido/irrigación sanguíneaRESUMEN
This study was performed to determine whether stimulation of the carotid chemoreceptors increases total or regional cerebral blood flow and whether activation of arterial chemoreceptors contributes to cerebral vasodilation during systemic hypoxemia. In anesthetized and ventilated dogs, carotid chemoreceptors were stimulated with nicotine or hypoxic and hypercapnic blood. To measure total and regional cerebral blood flow, we used labeled 15-mu microspheres. Stimulation of chemoreceptors did not increase cerebral blood flow or produce significant redistribution of cerebral blood flow, even though the chemoreflex was intact in these animals (as manifested by vasoconstriction in muscle, kidney, and small bowel) and the cerebral vessels dilated in response to systemic hypercapnia. In other studies in anesthetized, ventilated dogs and rhesus monkeys, cerebral vasodilator responses to systemic hypoxemia were observed before and after denervation of carotid and aortic chemoreceptors. Systemic hypoxemia produced large and equivalent increases in cerebral blood flow before and after chemodenervation. We conclude that stimulation of carotid chemoreceptors does not produce cerebral vasodilation and that chemoreceptors do not contribute significantly to cerebral vasodilation during systemic hypoxemia.
Asunto(s)
Cuerpo Carotídeo/fisiología , Seno Carotídeo/fisiología , Circulación Cerebrovascular , Animales , Presión Sanguínea , Núcleo Caudado/irrigación sanguínea , Cerebelo/irrigación sanguínea , Corteza Cerebral/irrigación sanguínea , Cuerpo Calloso/irrigación sanguínea , Perros , Bulbo Raquídeo/irrigación sanguínea , Mesencéfalo/irrigación sanguínea , Nicotina/farmacología , Oxígeno/sangre , Estimulación Física , Puente/irrigación sanguínea , Tálamo/irrigación sanguínea , Resistencia VascularRESUMEN
A method is described to measure regional blood flow in different structures of the rat brain. Microspheres (15 micron) are injected, the brain is sectioned, stained for myeline, radioautographs are prepared and the microspheres in the different structures are counted. The values obtained for different brain structures are counted. The values obtained for different brain regions (cortex, corpus callosum, thalamus hipocampus, hypothalamic region, colliculi, cerebellum, pons, medulla) compare well with those published by others on larger animals. In rats fed 1% of lead from birth, higher blood flow is found in the cortex and a lower one in the interior part of the brain compared to controls.