scholarly journals Functional Cerebral Activity during Regeneration from Entorhinal Lesions in the Rat

1996 ◽  
Vol 16 (2) ◽  
pp. 342-352 ◽  
Author(s):  
Thomas Beck ◽  
Michael Weber ◽  
Ervin Horváth ◽  
Andreas Wree
Keyword(s):  
Functional Activity ◽  
Glucose Utilization ◽  
Recovery Period ◽  
Brain Regions ◽  
Primary Target ◽  
Local Cerebral Glucose Utilization ◽  
Brain Areas ◽  
Ipsilateral Hemisphere ◽  
Entorhinal Lesion ◽  
Deoxyglucose Method

The consequences of an unilateral electrolytic entorhinal lesion on the functional activity in all major anatomically defined brain regions were evaluated in the rat. The 14C-2-deoxyglucose method served as a tool to quantify alterations of local cerebral glucose utilization (LCGU) ipsilateral and contralateral to the lesion at 4 days, 2 weeks, or 3 months after stereotaxic surgery. Apart from a few minor increases in the contralateral hemisphere, the predominant pattern consisted of reductions in the range of 10–40% in the ipsilateral hemisphere. Ipsilaterally, in extrahippocampal areas, LCGU had regained control levels at 2 weeks postlesion in contrast to hippocampal regions, where reductions were more pronounced than in other brain areas and partially persisted for up to 3 months. Interestingly, the termination zones of entorhinal fibers in the dentate gyrus did not regain control levels within 3 months. We conclude from the data that functional recovery of denervated primary target areas does not occur within 3 months after entorhinal lesions and that altered functional activity may be found beyond the primary target areas predominantly during the acute recovery period after the lesion. The data suggest that sprouting fibers do not reestablish a fully functional neuronal network during the recovery period.

Local cerebral glucose utilization in brains of lean and genetically obese (fa/fa) rats

1993 ◽  
Vol 264 (1) ◽  
pp. E29-E36
Author(s):  
P. Doyle ◽  
F. Rohner-Jeanrenaud ◽  
B. Jeanrenaud
Keyword(s):  
Gray Matter ◽  
Functional Activity ◽  
Wistar Rats ◽  
Glucose Utilization ◽  
Local Cerebral Glucose Utilization ◽  
Brain Areas ◽  
Afferent Pathways ◽  
Cerebral Glucose Utilization ◽  
Normal Glucose ◽  
Obesity Syndrome

The local cerebral glucose utilization (LCGU) of brains from Wistar, lean Zucker (FA/FA), and obese Zucker (fa/fa) rats was investigated using the method of Sokoloff et al. (L. Sokoloff, M. Reiwich, C. Kennedy, M.H. Des Rosiers, C.S. Patlak, K.D. Pettigrew, O. Sakurada, and M. Shinohara. J. Neurochem. 28: 897–916, 1977.). The LCGU of obese Zucker (fa/fa) rats was decreased in comparison to the relatively high values obtained for the lean Zucker (FA/FA) rats in all gray matter areas studied, on average to the extent of 50%. When compared with Wistar rats, several brain areas of lean Zucker (FA/FA) animals had a normal glucose uptake. When these normal areas were assessed for common efferent and afferent pathways, it was found that many of these common connections had normal glucose utilizations. In direct comparison to the obese fa/fa rat, the LCGU rates of these areas were decreased, hinting that this would also be the case for their functional activity. Because these areas (limbic, thalamic, hypothalamic, autonomic) have been reported to be potentially relevant for bringing about the behavioral and neuroendocrine alterations known to occur in obese fa/fa rats, it is proposed that they represent dysfunctions that are partly responsible for the obesity syndrome of the fa/fa strain.

Pentobarbital produces dissimilar changes in glucose influx and utilization in brain

1991 ◽  
Vol 261 (2) ◽  
pp. R265-R275
Author(s):  
T. Otsuka ◽  
L. Wei ◽  
D. Bereczki ◽  
V. Acuff ◽  
C. Patlak ◽  
...  
Keyword(s):  
Glucose Utilization ◽  
Brain Structures ◽  
Maximal Velocity ◽  
Local Cerebral Glucose Utilization ◽  
Brain Areas ◽  
Influx Rate ◽  
Half Saturation Constant ◽  
Permeability Surface ◽  
Area Product ◽  
Glucose Carrier

The effects of pentobarbital sodium on local cerebral glucose utilization (LCGU) and 3-O-methylglucose (3-MG) influx were measured by quantitative autoradiography in 52 brain areas of control and treated rats. Pentobarbital (50 mg/kg ip) lowered LCGU to a relatively uniform rate (approximately 35 mumol.100 g-1.min-1) in 24 of 25 forebrain areas. Among the 18 hindbrain areas, LCGU was decreased by pentobarbital by 15-55% (range 50-157 and 28-110 mumol.100 g-1.min-1 in control and treated rats, respectively). In contrast, pentobarbital lowered the 3-MG influx rate constant and permeability-surface area product by 20-30% in nearly all brain structures. The 3-MG results fit a model in which both the half-saturation constant and the maximal velocity of the glucose carrier are decreased by pentobarbital. After pentobarbital treatment, the ratio of local cerebral plasma flow (LCPF) to LCGU was the same as in controls for brain areas in which LCGU was less than 35 mumol.100 g-1.min-1 but was higher in brain areas where LCGU exceeded 35 mumol.100 g-1.min-1. Pentobarbital produced dissimilar changes in LCGU, 3-MG influx, and LCPF; these processes may thus not be closely linked during pentobarbital anesthesia.

Local cerebral glucose utilization in fetal and neonatal sheep

1984 ◽  
Vol 246 (4) ◽  
pp. R608-R618 ◽  
Author(s):  
R. M. Abrams ◽  
M. Ito ◽  
J. E. Frisinger ◽  
C. S. Patlak ◽  
K. D. Pettigrew ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Glucose Utilization ◽  
Average Rate ◽  
Sensory Stimulation ◽  
Mammalian Brain ◽  
Local Cerebral Glucose Utilization ◽  
Cerebral Energy Metabolism ◽  
Cerebral Glucose Utilization ◽  
The Brain ◽  
Deoxyglucose Method

The newborn mammalian brain of several species has been shown to have a lower average rate of energy metabolism and a narrower range of rates in its various components than is found in maturity. In a further study of cerebral energy metabolism during development, we have employed the [14C]deoxyglucose method for measuring local cerebral glucose utilization in fetal and neonatal sheep. After establishing the lumped constant to be 0.40 and finding the rate constants for the kinetic behavior of deoxyglucose in plasma and brain to be close to those in other species, we measured the rates of glucose utilization in 44 regions of the brain. The rates were low and homogeneous in midgestation, except for those of brain stem nuclei of the auditory and vestibular systems and those of the hippocampus which were relatively high. In the last 7 wk, local rates rose approximately threefold. After birth there was a further average increase of 50% above full-term levels. The study shows that cerebral energy metabolism rises in most structures during prenatal maturation, a time when sensory stimulation is at a relatively low level and behavioral responses are minimal.

Relative cerebral glucose metabolism evoked by dental-pulp stimulation in the rat

1979 ◽  
Vol 51 (1) ◽  
pp. 12-17 ◽  
Author(s):  
Andrew G. Shetter ◽  
William H. Sweet
Keyword(s):  
Dental Pulp ◽  
Glucose Utilization ◽  
Glucose Consumption ◽  
Brain Regions ◽  
Tooth Pulp ◽  
Incisor Tooth ◽  
Mandibular Incisor ◽  
Content Type ◽  
Deoxyglucose Method ◽  
Stimulation Of

✓ Electrical stimulation of dental pulp is widely acknowledged to produce a sensation that is predominantly or exclusively noxious in character. The authors report the pattern of local cerebral glucose utilization evoked by dental-pulp stimulation in the barbiturate-anesthetized rat, using the [14C]2-deoxyglucose method of Sokoloff. Autoradiographs were prepared from cryostat-cut brain sections of animals given an intravenous pulse of [14C]2-deoxyglucose and sacrificed after 45 minutes of continuous bipolar stimulation of the incisor tooth pulp. Areas of high optical density on the autoradiographs identified brain regions where glucose consumption, and hence functional activity, was maximal. Stimulus-related increases in glucose utilization were seen ipsilaterally in an uninterrupted column from the lower levels of trigeminal nucleus caudalis to the rostral extent of the main sensory nucleus. Mandibular incisor pulp stimulation yielded increased deoxyglucose uptake in relatively restricted dorsal portions of the nuclei, while maxillary pulp stimulation produced a more extensive area of uptake ventrally. Elevated deoxyglucose uptake was also seen in the contralateral ventrobasal thalamus and sensory cortex with maxillary, but not mandibular, pulp stimulation. No changes in metabolic activity were detected in extralemniscal or limbic structures. These initial results suggest that the [14C]2-deoxyglucose method may be a useful means of mapping central structures involved in nociception.

scholarly journals Effects of Insulin on Local Cerebral Glucose Utilization in the Rat

1987 ◽  
Vol 7 (3) ◽  
pp. 309-314 ◽  
Author(s):  
Giovanni Lucignani ◽  
Hiroki Namba ◽  
Astrid Nehlig ◽  
Linda J. Porrino ◽  
Charles Kennedy ◽  
...  
Keyword(s):  
Steady State ◽  
Glucose Utilization ◽  
Average Rate ◽  
Experimental Period ◽  
Ventromedial Nucleus ◽  
Local Cerebral Glucose Utilization ◽  
Cerebral Glucose Utilization ◽  
Hypothalamic Nuclei ◽  
The Brain ◽  
Deoxyglucose Method

The effects of hyperinsulinemia on local cerebral glucose utilization were studied by the quantitative autoradiographic 2-[14C]deoxyglucose method in normal conscious rats under steady-state normoglycemic conditions. Hyperinsulinemia and a steady state of normoglycemia were achieved and maintained during the experimental period by a continuous intravenous (i.v.) infusion of insulin given simultaneously with a programmed i.v. infusion of D-glucose. Hyperinsulinemia under normoglycemic conditions did not change the average rate of glucose utilization in the brain as a whole, but significant increases in local glucose utilization were found selectively in the ventromedial, dorsomedial, and anterior hypothalamic nuclei. The results suggest that a known anatomical pathway linking the dorsomedial and anterior nuclei with the ventromedial nucleus of the hypothalamus may be physiologically activated in response to hyperinsulinemia.

scholarly journals Focal Increases of White Matter Glucose Utilization Produced by Electrical Stimulation of Rat Motor Cortex

1983 ◽  
Vol 3 (1) ◽  
pp. 67-70 ◽  
Author(s):  
Frank R. Sharp ◽  
Sherzad Bzorgchami ◽  
Thomas Kilduff
Keyword(s):  
Electrical Stimulation ◽  
White Matter ◽  
Motor Cortex ◽  
Glucose Utilization ◽  
Pyramidal Tract ◽  
Internal Capsule ◽  
Local Cerebral Glucose Utilization ◽  
The Right ◽  
Deoxyglucose Method ◽  
Stimulation Of

The right motor cortex was electrically stimulated in adult, awake rats for 45 min. Local cerebral glucose utilization (LCGU) was measured in white matter pathways with the (14C)-2-deoxyglucose method. Stimulation increased LCGU in focal regions of the right internal capsule to 51.3 μmol/100 g/min, compared to 39.8 on the control left side. Stimulation also increased LCGU in the right, medial pontine pyramidal tract to 36.2 μmol/100 g/min, compared with 27.3 on the control left side. The data demonstrate that electrical stimulation of motor cortex neurons increases LCGU 30 to 40% in the efferent myelinated axons of those neurons.

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