A Specific Role for the Right Parahippocampal Gyrus in the Retrieval of Object-Location: A Positron Emission Tomography Study

1996 ◽  
Vol 8 (6) ◽  
pp. 588-602 ◽  
Author(s):  
Adrian M. Owen ◽  
Brenda Milner ◽  
Michael Petrides ◽  
Alan C. Evans
Keyword(s):  
Positron Emission Tomography ◽  
Critical Role ◽  
Emission Tomography ◽  
Object Location ◽  
Parahippocampal Gyrus ◽  
Hippocampal Region ◽  
Location Memory ◽  
Object Location Memory ◽  
Positron Emission ◽  
The Right

A plethora of studies, across many species, have now demonstrated that the hippocampal region plays a critical role in memory for spatial location. In spite of this compelling evidence, a number of important neuropsychological and neuroanatomical issues remain unresolved. In the present study, the functional anatomy of object-location memory was investigated using positron emission tomography (PET) with magnetic resonance imaging (MRI). Regional cerebral blood flow (rCBF) was measured while normal volunteers encoded, and then retrieved, the locations of eight familiar objects presented on a computer screen. In two analogous conditions, designed to fractionate object-location memory into its component processes, the subjects were simply required to encode, and then to retrieve, eight distinct locations represented by identical white boxes on the screen. An increase in rCBF was observed in the region of the right parahippocampal gyrus corresponding to entorhinal cortex when the Retrieving Location condition was subtracted from the Retrieving Object-Location condition. In contrast, when the Encoding Location condition was subtracted from the Encoding Object-Location condition, no significant rCBF changes were observed in the hippocampal region although significant activation was observed, bilaterally, in the anterior fusiform gyrus. In addition, the two encoding conditions activated left-hemisphere regions preferentially, whereas the two retrieval conditions activated right-hemisphere regions. Together, these findings suggest that the human right hippocampal region is critically involved in retrieving information that links object to place. The secondary finding that encoding and retrieval appear to be lateralized to the left and right hemispheres respectively, is discussed with reference to current models of episodic memory, and alternative hypotheses are considered.

Dopamine D2/3 receptor availability and human cognitive impulsivity: a high-resolution positron emission tomography imaging study with [11C]raclopride

2013 ◽  
Vol 26 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Jong-Hoon Kim ◽  
Young-Don Son ◽  
Hang-Keun Kim ◽  
Sang-Yoon Lee ◽  
Young-Bo Kim ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
High Resolution ◽  
Animal Studies ◽  
Critical Role ◽  
Positron Emission Tomography Imaging ◽  
Imaging Study ◽  
Emission Tomography ◽  
Positron Emission ◽  
Character Inventory ◽  
Behavioural Aspects

ObjectiveHuman impulsivity is a complex multidimensional construct encompassing cognitive, emotional, and behavioural aspects. Previous animal studies have suggested that striatal dopamine receptors play a critical role in impulsivity. In this study, we investigated the relationship between self-reported impulsiveness and dopamine D2/3 receptor availability in striatal subdivisions in healthy subjects using high-resolution positron emission tomography (PET) with [11C]raclopride.MethodsTwenty-one participants completed 3-T magnetic resonance imaging and high-resolution PET scans with [11C]raclopride. The trait of impulsiveness was measured using the Barratt Impulsiveness Scale (BIS-11). Partial correlation analysis was performed between BIS-11 scores and D2/3 receptor availability in striatal subregions, controlling for the confounding effects of temperament characteristics that are conceptually or empirically related to dopamine, which were measured by the Temperament and Character Inventory.ResultsThe analysis revealed that the non-planning (p = 0.004) and attentional (p = 0.007) impulsiveness subscale scores on the BIS-11 had significant positive correlations with D2/3 receptor availability in the pre-commissural dorsal caudate. There was a tendency towards positive correlation between non-planning impulsiveness score and D2/3 receptor availability in the post-commissural caudate.ConclusionThese results suggest that cognitive subtrait of impulsivity is associated with D2/3 receptor availability in the associative striatum that plays a critical role in cognitive processes involving attention to detail, judgement of alternative outcomes, and inhibitory control.

Whole body muscle activity during weightlifting exercise evaluated by positron emission tomography

2021 ◽  
Author(s):  
Rikuto Yoshimizu ◽  
Junsuke Nakase ◽  
Takafumi Mochizuki ◽  
Yasushi Takata ◽  
Kengo Shimozaki ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Muscle Activity ◽  
Erector Spinae ◽  
Triceps Surae ◽  
Emission Tomography ◽  
Whole Body ◽  
Computed Tomography Images ◽  
Positron Emission ◽  
The Right ◽  
Fdg Accumulation

Abstract BackgroundThis study investigated the whole-body skeletal muscle activity pattern of hang power clean (HPC), a major weight training exercise, using positron emission tomography (PET).MethodTwelve college weightlifting athletes performed three sets of HPC 20 times with a barbell set to 40 kg both before and after an intravenous injection of 37 MBq 18F-fluorodeoxyglucose (FDG). PET-computed tomography images were obtained 50 min after FDG injection. Regions of interest were defined within 71 muscles. The standardized uptake value was calculated to examine the FDG uptake of muscle tissue per unit volume, and FDG accumulation was compared to the control group. The Mann–Whitney U-test was used to evaluate the differences in the mean SUV between groups. The difference between SUVs of the right and left muscles was evaluated by a paired t-test. A P-value < 0.05 was considered statistically significant.ResultsFDG accumulation within the vastus lateralis, vastus intermedius, and vastus medialis was higher than that of the rectus femoris. FDG accumulation within the triceps surae muscle was significantly higher only in the soleus. In the trunk and hip muscles, FDG accumulation of only the erector spinae was significantly increased. In all skeletal muscles, there was no difference between SUVs of the right and left muscles.ConclusionsThe monoarticular muscles in the lower limbs were active in HPC. In contrast, deep muscles in the trunk and hip were not active during HPC. HPC is not suitable for core training and needs to be supplemented with other training.

scholarly journals JAZF1–SUZ12 endometrial stromal sarcoma forming subserosal masses with extraordinary uptake of fluorodeoxyglucose on positron emission tomography: a case report

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Koto Fujiishi ◽  
Shigenori Nagata ◽  
Rieko Kano ◽  
Chiaki Kubo ◽  
Maasa Shirayanagi ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Endometrial Stromal Sarcoma ◽  
Emission Tomography ◽  
Low Grade ◽  
Neoplastic Cells ◽  
Pelvic Magnetic Resonance Imaging ◽  
Stromal Sarcoma ◽  
Positron Emission ◽  
Mesenchymal Neoplasm ◽  
The Right

Abstract Background Low-grade endometrial stromal sarcoma (ESS) is rare mesenchymal neoplasm, recently specified as harboring JAZF1–SUZ12 rearrangement. Typical JAZF1–SUZ12 ESS is slow growing, in which high uptake of fluorodeoxyglucose (FDG) on positron emission tomography (PET) and subserosal masses are quite unusual. Case presentation A 69-year-old Japanese woman complained of urinary incontinence. Pelvic magnetic resonance imaging showed uterine lesions composed of (1) a 9 × 8 × 7-cm mass protruding from the right-anterior wall, (2) a 4.5-cm mass attached to the right-posterior wall, and (3) a 6.5-cm intramural mass in the fundus. FDG-PET demonstrated maximum standardized uptake value of 13.28 confined to the two subserosal masses (1 & 2) in contrast to no uptake of the intramural mass (3). She was diagnosed with a high-grade uterine sarcoma concomitant with leiomyomas and underwent total hysterectomy with bilateral salpingo-oophorectomy and pelvic lymphadenectomy. The removed uterus had three tumors—two in the right-anterior and right-posterior subserosa, respectively, and the remaining in the fundal myometrium. Microscopically, the three tumors shared morphologic features characterized by neoplastic cells similar to proliferative-phase endometrial stromal cells, in which neither round-cell component, pleomorphism, nor high mitotic activity was recognized. Nuclear cyclin D1 immunostaining was identified 50% of neoplastic cells in the two subserosal tumors (1 &2) whereas < 1% positive cells in the intramural component (3). Reverse transcriptase-polymerase chain reaction showed the same-sized electrophoretic bands indicating JAZF1–SUZ12 gene fusion shared by the three uterine tumors and a focal tumor extension into the extrauterine vein. The patient is alive without evidence of recurrence at 14 months after surgery. Conclusions Pathologists and clinicians should not exclude the possibility of JAZF1–SUZ12 ESS even when uterine subserosal masses demonstrate extraordinary FDG uptake on PET. Molecular analysis is helpful for diagnostic confirmation of JAZF1–SUZ12 ESS with a complex growth pattern.

scholarly journals Imaging Human Mesolimbic Dopamine Transmission with Positron Emission Tomography: I. Accuracy and Precision of D2 Receptor Parameter Measurements in Ventral Striatum

2001 ◽  
Vol 21 (9) ◽  
pp. 1034-1057 ◽  
Author(s):  
Osama Mawlawi ◽  
Diana Martinez ◽  
Mark Slifstein ◽  
Allegra Broft ◽  
Rano Chatterjee ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
High Resolution ◽  
Ventral Striatum ◽  
Critical Role ◽  
Intraclass Correlation ◽  
Emission Tomography ◽  
Binding Potential ◽  
Positron Emission ◽  
Accuracy And Precision ◽  
Dopamine Transmission

Dopamine transmission in the ventral striatum (VST), a structure which includes the nucleus accumbens, ventral caudate, and ventral putamen, plays a critical role in the pathophysiology of psychotic states and in the reinforcing effects of virtually all drugs of abuse. The aim of this study was to assess the accuracy and precision of measurements of D2 receptor availability in the VST obtained with positron emission tomography on the high-resolution ECAT EXACT HR+ scanner (Siemens Medical Systems, Knoxville, TN, U.S.A.). A method was developed for identification of the boundaries of the VST on coregistered high-resolution magnetic resonance imaging scans. Specific-to-nonspecific partition coefficient (V3″) and binding potential (BP) of [11C]raclopride were measured twice in 10 subjects, using the bolus plus constant infusion method. [11C]Raclopride V3″ in the VST (1.86 ± 0.29) was significantly lower than in the dorsal caudate (DCA, 2.33 ± 0.28) and dorsal putamen (DPU, 2.99 ± 0.26), an observation consistent with postmortem studies. The reproducibility of V3″ and BP were appropriate and similar in VST (V3″ test–retest variability of 8.2% ± 6.2%, intraclass correlation coefficient = 0.83), DCA (7.7% ± 5.1%, 0.77), DPU (6.0% ± 4.1%, 0.71), and striatum as a whole (6.3% ± 4.1%, 0.78). Partial volume effects analysis revealed that activities in the VST were significantly contaminated by counts spilling over from the adjacent DCA and DPU: 70% ± 5% of the specific binding measured in the VST originated from D2 receptors located in the VST, whereas 12% ± 3% and 18% ± 3% were contributed by D2 receptors in the DCA and DPU, respectively. Thus, accuracy of D2 receptor measurement is improved by correction for partial voluming effects. The demonstration of an appropriate accuracy and precision of D2 receptor measurement with [11C]raclopride in the VST is the first critical step toward the use of this ligand in the study of synaptic dopamine transmission at D2 receptors in the VST using endogenous competition techniques.

scholarly journals Adult attention-deficit/hyperactivity disorder is associated with reduced norepinephrine transporter availability in right attention networks: a (S,S)-O-[11C]methylreboxetine positron emission tomography study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christine Ulke ◽  
Michael Rullmann ◽  
Jue Huang ◽  
Julia Luthardt ◽  
Georg-Alexander Becker ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
Adult Adhd ◽  
Critical Role ◽  
Norepinephrine Transporter ◽  
Emission Tomography ◽  
Controlled Study ◽  
Hyperactivity Disorder ◽  
Positron Emission

AbstractThe norepinephrine transporter (NET) has been suggested to play a critical role in attention-deficit/hyperactivity disorder (ADHD). In this prospective controlled study we tested the a-priori-hypothesis that central NET availability is altered in adult ADHD patients compared to healthy controls. Study participants underwent single positron emission tomography-magnetic resonance imaging (PET-MRI). MRI sequences included high resolution T1-MPRAGE data for regions of interest (ROI) delineation and voxel-based morphometry (VBM) and T2-weighted fluid-attenuated inversion-recovery for detection and exclusion of pathological abnormalities. NET availability was assessed by NET-selective (S,S)-O-[11C]methylreboxetine; regional distribution volume ratios (DVR) were calculated based on individual PET-MRI data co-registration and a multi-linear reference tissue model with two constraints (MRTM2; reference region: occipital cortex). VBM analysis revealed no difference in local distribution of gray matter between the 20 ADHD patients (9 females, age 31.8 ± 7.9 years, 488 ± 8 MBq injected activity) and the 20 age-matched and sex-matched control participants (9 females, age 32.3 ± 7.9 years, 472 ± 72 MBq). In mixed-model repeated-measures analysis with NET availability as dependent and ROI as repeated measure we found a significant main effect group in fronto-parietal-thalamic-cerebellar regions (regions on the right: F1,25 = 12.30, p = .002; regions on the left: F1,41 = 6.80, p = .013) indicating a reduced NET availability in ADHD patients. None of the other investigated brain regions yielded significant differences in NET availability between groups after applying a Benjamini-Hochberg correction at a significance level of 0.05. Overall our findings demonstrate the pathophysiological involvement of NET availability in adult ADHD.

scholarly journals Cerebral [15O] Water Clearance in Humans Determined by Positron Emission Tomography: II. Vascular Responses to Vibrotactile Stimulation

1997 ◽  
Vol 17 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Hitoshi Fujita ◽  
Ernst Meyer ◽  
David C. Reutens ◽  
Hiroto Kuwabara ◽  
Alan C. Evans ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Emission Tomography ◽  
Mr Images ◽  
Vibrotactile Stimulation ◽  
Positron Emission ◽  
The Right ◽  
The Brain ◽  
Hand Area ◽  
Water Clearance

When used to measure blood flow, water leaves a residue in the vascular bed, which may contribute to the calculation of increased blood flow during functional activation of brain tissue. To assess the magnitude of this contribution with the two-compartment positron emission tomography (PET) method, we mapped the water clearance ( K1) of the brain as an index of cerebral blood flow (CBF) and the apparent vascular distribution of nonextracted H215O ( Vo). The latter map represented mainly the cerebral arterial and arteriolar volume. We also prepared subtraction maps (Δ K1, Δ Vo) of the response to vibrotactile stimulation of the fingertips of the right hand of six normal volunteers. Using magnetic resonance (MR) images of all subjects, the data were rendered into Talairach's stereotaxic coordinates and the averaged subtraction images (activation minus baseline) merged with the corresponding averaged MRI image. The Δ K1 map revealed the expected response in the primary sensory hand area; the Δ Vo response was located about 13 mm more anteriorly, close to the central fissure, most likely reflecting changes of the arteries feeding the primary sensory hand area. We conclude that cerebral perfusion and cerebrovascular responses to vibrotactile stimulation may occur in disparate locations that can be identified separately by using the two-compartment method.

scholarly journals Intracerebral Hemorrhage after Carotid Artery Stenting without Evidence of Hyperperfusion in Positron Emission Tomography

2007 ◽  
Vol 13 (2) ◽  
pp. 191-199 ◽  
Author(s):  
A. Shindo ◽  
N. Kawai ◽  
K. Kawakita ◽  
M. Kawanishi ◽  
T. Tamiya ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Carotid Artery ◽  
Intracerebral Hemorrhage ◽  
Left Hemisphere ◽  
Carotid Artery Stenting ◽  
Right Hemisphere ◽  
Emission Tomography ◽  
Oxygen Extraction Fraction ◽  
Positron Emission ◽  
The Right

A 75-year-old man with a recent history of transient left hemiparesis and dysarthria was referred to our hospital. Angiography showed right internal carotid artery (ICA) occlusion and left ICA 89% stenosis. Positron emission tomography (PET) showed decreased cerebral blood flow (CBF), and increased oxygen extraction fraction (OEF) and cerebral blood volume (CBV) in the right hemisphere. In the left hemisphere, CBV was increased, but CBF and OEF remained normal. One month after the transient ischemic attack, left carotid artery stenting (CAS) was performed without complications. Diffusion-weighted magnetic resonance imaging (MRI) on the day after CAS showed no fresh ischemic lesion. PET on the second day after CAS showed increased CBF and decreased OEF and CBV in the right hemisphere as compared with those before CAS. In the left hemisphere, decreased CBV was observed and CBF was slightly increased as compared with those before CAS. The postoperative course was uneventful, but on the fifth day after CAS, the patient suddenly showed a focal seizure and right motor weakness. Emergency computed tomography scanning showed massive intracranial hemorrhage with severe brain edema in the left hemisphere. Although CBF study is useful to predict the hyperperfusion syndrome, we cannot disregard the possibility of intracerebral hemorrhage after CAS for carotid artery stenosis when there is no evidence of hyperperfusion on postoperative CBF study.

Frontal and Parietal Networks for Conditional Motor Learning: A Positron Emission Tomography Study

1997 ◽  
Vol 78 (2) ◽  
pp. 977-991 ◽  
Author(s):  
M.-P. Deiber ◽  
S. P. Wise ◽  
M. Honda ◽  
M. J. Catalan ◽  
J. Grafman ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Posterior Parietal Cortex ◽  
Right Hemisphere ◽  
Motor Task ◽  
Emission Tomography ◽  
Arbitrary Mapping ◽  
Positron Emission ◽  
Evaluation Task ◽  
Area 6 ◽  
The Right

Deiber, M.-P., S. P. Wise, M. Honda, M. J. Catalan, J. Grafman, and M. Hallett. Frontal and parietal networks for conditional motor learning: a positron emission tomography study. J. Neurophysiol. 78: 977–991, 1997. Studies on nonhuman primates show that the premotor (PM) and prefrontal (PF) areas are necessary for the arbitrary mapping of a set of stimuli onto a set of responses. However, positron emission tomography (PET) measurements of regional cerebral blood flow (rCBF) in human subjects have failed to reveal the predicted rCBF changes during such behavior. We therefore studied rCBF while subjects learned two arbitrary mapping tasks. In the conditional motor task, visual stimuli instructed which of four directions to move a joystick (with the right, dominant hand). In the evaluation task, subjects moved the joystick in a predetermined direction to report whether an arrow pointed in the direction associated with a given stimulus. For both tasks there were three rules: for the nonspatial rule, the pattern within each stimulus determined the correct direction; for the spatial rule, the location of the stimulus did so; and for the fixed-response rule, movement direction was constant regardless of the pattern or its location. For the nonspatial rule, performance of the evaluation task led to a learning-related increase in rCBF in a caudal and ventral part of the premotor cortex (PMvc, area 6), bilaterally, as well as in the putamen and a cingulate motor area (CM, area 24) of the left hemisphere. Decreases in rCBF were observed in several areas: the left ventro-orbital prefrontal cortex (PFv, area 47/12), the left lateral cerebellar hemisphere, and, in the right hemisphere, a dorsal and rostral aspect of PM (PMdr, area 6), dorsal PF (PFd, area 9), and the posterior parietal cortex (area 39/40). During performance of the conditional motor task, there was only a decrease in the parietal area. For the spatial rule, no rCBF change reached significance for the evaluation task, but in the conditional motor task, a ventral and rostral premotor region (PMvr, area 6), the dorsolateral prefrontal cortex (PFdl, area 46), and the posterior parietal cortex (area 39/40) showed decreasing rCBF during learning, all in the right hemisphere. These data confirm the predicted rCBF changes in premotor and prefrontal areas during arbitrary mapping tasks and suggest that a broad frontoparietal network may show decreased synaptic activity as arbitrary rules become more familiar.

Sign in / Sign up

Export Citation Format

Share Document