scholarly journals The influence of conditioned stimuli on [11C]-(+)-PHNO PET binding in tobacco smokers after a one week abstinence

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Patricia Di Ciano ◽  
Harriet de Wit ◽  
Esmaeil Mansouri ◽  
Sylvain Houle ◽  
Isabelle Boileau ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Preliminary Finding ◽  
Regions Of Interest ◽  
Ventral Pallidum ◽  
Binding Potential ◽  
Brain Areas ◽  
Positron Emission ◽  
Smoking Cues ◽  
Pet Scans ◽  
Larger Sample

AbstractStimuli previously paired with drugs of dependence can produce cravings that are associated with increased dopamine (DA) levels in limbic and striatal brain areas. Positron Emission Tomography (PET) imaging with [11C]-(+)-PHNO allows for a sensitive measurement of changes in DA levels. The purpose of the present study was to investigate changes in DA levels, measured with PET imaging with [11C]-(+)-PHNO, in regions of interest in smokers who had maintained abstinence for 7–10 days. Participants (N = 10) underwent two PET scans on separate days, during which they viewed either smoking-related or neutral images, in counterbalanced order. Craving was measured with the 12-item Tobacco Craving Questionnaire (TCQ) and the Questionnaire on Smoking Urges-Brief (QSU-B). Compared to neutral cues, smoking cues did not increase craving. There were no changes in [11C]-(+)-PHNO binding in the cue condition compared to the neutral condition for most regions of interest (ventral pallidum, globus pallidus, limbic striatum, associative striatum, sensorimotor striatum). However, binding potential in the substantia nigra was greater in the smoking-cue condition, indicating decreased synaptic dopamine. There is a potential change of DA level occurring in midbrain following the presentation of smoking-related cues. However, this preliminary finding would need to be validated with a larger sample.

scholarly journals The influence of Conditioned Stimuli on [11C]-(+)-PHNO PET Binding in Tobacco Smokers after a One Week Abstinence

2021 ◽  
Author(s):  
Patricia Di Ciano ◽  
Harriet de Wit ◽  
Esmaeil Mansouri ◽  
Sylvain Houle ◽  
Isabelle Boileau ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Neutral Condition ◽  
Regions Of Interest ◽  
Emission Tomography ◽  
Ventral Pallidum ◽  
Binding Potential ◽  
Brain Areas ◽  
Positron Emission ◽  
Smoking Cues ◽  
Pet Scans

Abstract Stimuli previously paired with drugs of dependence can produce cravings that are associated with increased dopamine (DA) levels in limbic and striatal brain areas. Positron Emission Tomography (PET) imaging with [11C]-(+)-PHNO allows for a sensitive measurement of changes in DA levels. The purpose of the present study was to investigate changes in DA levels, measured with PET imaging with [11C]-(+)-PHNO, in regions of interest in smokers who had maintained abstinence for 7-10 days. Participants (N=10) underwent two PET scans on separate days, during which they viewed either smoking-related or neutral images, in counterbalanced order. Craving was measured with the 12-item Tobacco Craving Questionnaire (TCQ) and the Questionnaire on Smoking Urges-Brief (QSU-B). Compared to neutral cues, smoking cues did not increase craving. There were no changes in [11C]-(+)-PHNO binding in the cue condition compared to the neutral condition for most regions of interest (ventral pallidum, globus pallidus, limbic striatum, associative striatum, sensorimotor striatum). However, binding potential in the substantia nigra was greater in the smoking-cue condition, indicating decreased synaptic dopamine. There is a potential change of DA level occurring in midbrain following the presentation of smoking-related cues.

In Vivo PET Measurements with [11C]PE2I to Evaluate Fetal Mesencephalic Transplantations to Unilateral 6-OHDA-Lesioned Rats

2005 ◽  
Vol 14 (9) ◽  
pp. 655-663 ◽  
Author(s):  
Motoki Inaji ◽  
Takahito Yoshizaki ◽  
Takashi Okauchi ◽  
Jun Maeda ◽  
Yuji Nagai ◽  
...  
Keyword(s):  
Dopamine Transporter ◽  
High Performance ◽  
Emission Tomography ◽  
Binding Potential ◽  
In Vitro Autoradiography ◽  
Positron Emission ◽  
Pet Scans ◽  
Mesencephalic Cells

Positron emission tomography (PET) is a useful tool to assess and visualize neurotransmissions in vivo. In this study, we performed repeated PET scans with [11C]PE2I, a tracer of the dopamine transporter, to evaluate the alteration of the expression of dopamine (DA) transmission component after a fetal mesencephalic transplantation. The fetal mesencephalic cells were transplanted into the striatum of unilateral 6-OHDA-lesioned rats. PET scans with [11C]PE2I were performed to evaluate the DA transporter before and 2 and 4 weeks after the transplantation. Rotation behavior tests, in vitro autoradiography, measurements of DA contents in the striatum by high-performance liquid chromatography (HPLC), and tyrosine hydroxylase (TH) immuno-histological examinations were performed at the same time points and examined for their relationship to changes in the dopamine transporter. The number of ipsilateral rotations induced by methamphetamine injections decreased. DA contents in the striatum measured with HPLC significantly increased. In the PET study, the binding potential of [11C]PE2I increased at 4 weeks. The results of the in vitro autoradiography study corresponded with those of the PET study. The degrees of the change in the binding potentials correlated with those of the numbers of rotations in the behavioral study and the DA contents in the striatum. In the histological examination, TH-positive cells with axons were observed at 2 and 4 weeks after the transplantation. As the dopamine transporter exists only in the axon terminal of DA neurons, these results suggested that PET measurements of [11C]PE2I binding indicated not only survival, but maturity and functioning of the transplanted cells. Repeated PET measurements of DA transporters are a useful tool in assessing the effectiveness of neural transplantations.

scholarly journals Evaluation of dopamine D3 receptor occupancy by blonanserin using [11C]-(+)-PHNO in schizophrenia patients

2020 ◽  
Author(s):  
Takeshi Sakayori ◽  
Amane Tateno ◽  
Ryosuke Arakawa ◽  
Woo-chan Kim ◽  
Yoshiro Okubo
Keyword(s):  
Substantia Nigra ◽  
Globus Pallidus ◽  
Healthy Subjects ◽  
Receptor Occupancy ◽  
Binding Potential ◽  
Positron Emission ◽  
Dopamine D3 ◽  
Continued Use ◽  
Pet Scans ◽  
Average Occupancy

Abstract Rationale Unlike other antipsychotics, our previous positron emission tomography (PET) study demonstrated that a single dose of blonanserin occupied dopamine D3 as well as dopamine D2 receptors in healthy subjects. However, there has been no study concerning the continued use of blonanserin. Objectives We examined D2 and D3 receptor occupancies in patients with schizophrenia who had been treated with blonanserin. Methods Thirteen patients with schizophrenia participated. PET examinations were performed on patients treated with clinical dosage of blonanserin or olanzapine alone. A crossover design was used in which seven patients switched drugs after the first scan, and PET examinations were conducted again. D2 and D3 receptor occupancies were evaluated by [11C]-(+)-PHNO. We used nondisplaceable binding potential (BPND) of 6 healthy subjects which we previously reported as baseline. To consider the effect of upregulation of D3 receptor by continued use of antipsychotics, D3 receptor occupancy by blonanserin in seven subjects who completed 2 PET scans were re-analyzed by using BPND of olanzapine condition as baseline. Results Average occupancy by olanzapine (10.8 ± 6.0 mg/day) was as follows: caudate 32.8 ± 18.3%, putamen 26.3 ± 18.2%, globus pallidus − 33.7 ± 34.9%, substantia nigra − 112.8 ± 90.7%. Average occupancy by blonanserin (12.8 ± 5.6 mg/day) was as follows: caudate 61.0 ± 8.3%, putamen 55.5 ± 9.5%, globus pallidus 48.9 ± 12.4%, substantia nigra 34.0 ± 20.6%. EC50 was 0.30 ng/mL for D2 receptor for caudate and putamen (df = 19, p < 0.0001) and 0.70 ng/mL for D3 receptor for globus pallidus and substantia nigra (df = 19, p < 0.0001). EC50 for D3 receptor of blonanserin changed to 0.22 ng/mL (df = 13, p = 0.0041) when we used BPND of olanzapine condition as baseline. Conclusions Our study confirmed that blonanserin occupied both D2 and D3 receptors in patients with schizophrenia.

scholarly journals 68Ga-NOTA PET imaging for gastric emptying assessment in mice

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xueyan Chen ◽  
Yu Liu ◽  
Donghui Pan ◽  
Maoyu Cao ◽  
Xinyu Wang ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Pet Imaging ◽  
Radiochemical Purity ◽  
Total Activity ◽  
Emission Tomography ◽  
Imaging Method ◽  
Dynamic Pet ◽  
Positron Emission ◽  
Reliable Quantification ◽  
Pet Scans

Abstract Background Positron emission tomography (PET) has the potential for visualization and quantification of gastric emptying (GE). The traditional Chinese medicine (TCM) has been recognized promising for constipation. This study aimed to establish a PET imaging method for noninvasive GE measurement and to evaluate the efficacy of a TCM on delayed GE caused by constipation using PET imaging. Methods [68Ga]Ga-NOTA was synthesized as the tracer and sesame paste with different viscosity were selected as test meals. The dynamic PET scans were performed after [68Ga]Ga-NOTA mixed with test meals were administered to normal mice. Two methods were utilized for the quantification of PET imaging. A constipation mouse model was treated with maren chengqi decoction (MCD), and the established PET imaging scans were performed after the treatment. Results [68Ga]Ga-NOTA was synthesized within 20 min, and its radiochemical purity was > 95%. PET images showed the dynamic process of GE. %ID/g, volume, and total activity correlated well with each other. Among which, the half of GE time derived from %ID/g for 4 test meals were 3.92 ± 0.87 min, 13.1 ± 1.25 min, 17.8 ± 1.31 min, and 59.7 ± 3.11 min, respectively. Constipation mice treated with MCD showed improved body weight and fecal conditions as well as ameliorated GE measured by [68Ga]Ga-NOTA PET. Conclusions A PET imaging method for noninvasive GE measurement was established with stable radiotracer, high image quality, and reliable quantification methods. The efficacy of MCD on delayed GE was demonstrated using PET.

scholarly journals Relevance of Brain 18F-FDG PET Imaging in Probable Seronegative Encephalitis With Catatonia: A Case Report

2021 ◽  
Vol 12 ◽  
Author(s):  
Michaël Guetta ◽  
Aurélie Kas ◽  
Aveline Aouidad ◽  
Marine Soret ◽  
Yves Allenbach ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Fdg Pet ◽  
Autoimmune Encephalitis ◽  
Treatment Decision ◽  
Systematic Assessment ◽  
Treatment Decision Making ◽  
Positron Emission ◽  
Progressive Encephalopathy ◽  
Pet Scans

Autoimmune encephalitis (AIE) is a rare, severe, and rapidly progressive encephalopathy, and its diagnosis is challenging, especially in adolescent populations when the presentation is mainly psychiatric. Currently, cerebral 18-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) imaging is not included in the diagnosis algorithm. We describe a 16-year-old patient with probable seronegative encephalitis with catatonia for which several cerebral PET scans were relevant and helpful for diagnosis, treatment decision making, and follow-up monitoring. The patient recovered after 2 years of treatment with etiologic treatment of AIE and treatment of catatonia. This case suggests a more systematic assessment of the clinical relevance of 18F-FDG-PET imaging in probable seronegative AIE.

scholarly journals The applicability of SRTM in [18F]fallypride PET investigations: Impact of scan durations

2011 ◽  
Vol 31 (9) ◽  
pp. 1958-1966 ◽  
Author(s):  
Ingo Vernaleken ◽  
Lisa Peters ◽  
Mardjan Raptis ◽  
Robert Lin ◽  
Hans-Georg Buchholz ◽  
...  
Keyword(s):  
Temporal Cortex ◽  
Receptor Occupancy ◽  
Binding Potential ◽  
Reference Tissue ◽  
Scan Time ◽  
Positron Emission ◽  
Simplified Reference Tissue Model ◽  
Pet Scans ◽  
Drug Free ◽  
Time Point

The high-affinity radioligand [18F]fallypride (FP) is frequently used for quantification of striatal/extrastriatal D2/3 receptors and the receptor occupancies of antipsychotics (APs). Its 110 minutes half-life allows long scan durations. However, the optimum scan duration is a matter of debate. This investigation focuses on scan-duration-related effects on simplified reference tissue model (SRTM) results and the time point of transient equilibrium in a large sample of dynamic FP positron emission tomography (PET) scans. Fifty drug-free and 50 AP-treated subjects underwent FP-PET scans (180 minutes scan duration). The binding potential ( BPND) of the putamen, thalamus, and temporal cortex were calculated using the SRTM and the transient equilibrium model. Furthermore, receptor occupancies were calculated for AP-treated patients. Transient equilibrium in the unblocked putamen occurred after 121 ± 29.6 minutes. The transient equilibrium occurred much earlier in the extrastriatal regions or under AP treatment. Stepwise scan shortening caused BPND under-estimations of 0.58% for the first 10-minute reduction (putamen, SRTM), finally reaching 5.76% after 1 hour scan-time reduction. We observed preferential extrastriatal AP binding irrespective of the analytical method. [18F]fallypride scan durations of 180 minutes reliably reach equilibrium even in D2/3-receptor-rich regions. Moderate reductions in FP scan durations only caused small changes to SRTM results even in receptor-rich regions. Apparently, the D2/3 receptor occupancy results of APs, especially preferential extrastriatal binding observations, are not relevantly biased by inappropriate scan durations.

scholarly journals 11C-DPA-713 has much greater specific binding to translocator protein 18 kDa (TSPO) in human brain than 11C-(R)-PK11195

2017 ◽  
Vol 38 (3) ◽  
pp. 393-403 ◽  
Author(s):  
Masato Kobayashi ◽  
Teresa Jiang ◽  
Sanjay Telu ◽  
Sami S Zoghbi ◽  
Roger N Gunn ◽  
...  
Keyword(s):  
Second Generation ◽  
Specific Binding ◽  
Translocator Protein ◽  
Emission Tomography ◽  
Binding Potential ◽  
Arterial Blood ◽  
Plot Analysis ◽  
Positron Emission ◽  
Translocator Protein 18 Kda ◽  
Pet Scans

Positron emission tomography (PET) radioligands for translocator protein 18 kDa (TSPO) are widely used to measure neuroinflammation, but controversy exists whether second-generation radioligands are superior to the prototypical agent 11C-( R)-PK11195 in human imaging. This study sought to quantitatively measure the “signal to background” ratio (assessed as binding potential ( BPND)) of 11C-( R)-PK11195 compared to one of the most promising second-generation radioligands, 11C-DPA-713. Healthy subjects had dynamic PET scans and arterial blood measurements of radioligand after injection of either 11C-( R)-PK11195 (16 subjects) or 11C-DPA-713 (22 subjects). To measure the amount of specific binding, a subset of these subjects was scanned after administration of the TSPO blocking drug XBD173 (30–90 mg PO). 11C-DPA-713 showed a significant sensitivity to genotype in brain, whereas 11C-( R)-PK11195 did not. Lassen occupancy plot analysis revealed that the specific binding of 11C-DPA-713 was much greater than that of 11C-( R)-PK11195. The BPND in high-affinity binders was about 10-fold higher for 11C-DPA-713 (7.3) than for 11C-( R)-PK11195 (0.75). Although the high specific binding of 11C-DPA-713 suggests it is an ideal ligand to measure TSPO, we also found that its distribution volume increased over time, consistent with the accumulation of radiometabolites in brain.

scholarly journals PET imaging of brain aromatase in humans and rhesus monkeys by 11C-labeled cetrozole analogs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kayo Takahashi ◽  
Takamitsu Hosoya ◽  
Kayo Onoe ◽  
Tomoko Mori ◽  
Shusaku Tazawa ◽  
...  
Keyword(s):  
Pet Imaging ◽  
High Specificity ◽  
Binding Potential ◽  
Similar Distribution ◽  
Time Activity ◽  
Brain Functions ◽  
Pet Tracer ◽  
Positron Emission ◽  
Brain Aromatase ◽  
Similar Distribution Pattern

AbstractAromatase is an estrogen synthetic enzyme that plays important roles in brain functions. To quantify aromatase expression in the brain by positron emission tomography (PET), we had previously developed [11C]cetrozole, which showed high specificity and affinity. To develop more efficient PET tracer(s) for aromatase imaging, we synthesized three analogs of cetrozole. We synthesized meta-cetrozole, nitro-cetrozole, and iso-cetrozole, and prepared the corresponding 11C-labeled tracers. The inhibitory activities of these three analogs toward aromatase were evaluated using marmoset placenta, and PET imaging of brain aromatase was performed using the 11C-labeled tracers in monkeys. The most promising analog in the monkey study, iso-cetrozole, was evaluated in the human PET study. The highest to lowest inhibitory activity of the analogs toward aromatase in the microsomal fraction from marmoset placenta was in the following order: iso-cetrozole, nitro-cetrozole, cetrozole, and meta-cetrozole. This order showed good agreement with the order of the binding potential (BP) of each 11C-labeled analog to aromatase in the rhesus monkey brain. A human PET study using [11C]iso-analog showed a similar distribution pattern of binding as that of [11C]cetrozole. The time–activity curves showed that elimination of [11C]iso-cetrozole from brain tissue was faster than that of 11C-cetrozole, indicating more rapid metabolism of [11C]iso-cetrozole. [11C]Cetrozole has preferable metabolic stability for brain aromatase imaging in humans, although [11C]iso-cetrozole might also be useful to measure aromatase level in living human brain because of its high binding potential.

scholarly journals Evaluation of Four Pyridine Analogs to Characterize 6-OHDA-Induced Modulation of mGluR5 Function in Rat Brain Using microPET Studies

2007 ◽  
Vol 27 (9) ◽  
pp. 1623-1631 ◽  
Author(s):  
Aijun Zhu ◽  
Xukui Wang ◽  
Meixiang Yu ◽  
Ji-Quan Wang ◽  
Anna-Liisa Brownell
Keyword(s):  
Positron Emission Tomography ◽  
Pet Imaging ◽  
Emission Tomography ◽  
Binding Potential ◽  
Sprague Dawley ◽  
Imaging Studies ◽  
Reference Tissue ◽  
Positron Emission ◽  
The Right

Micro-positron emission tomography imaging studies were conducted to characterize modulation of metabotropic glutamate subtype-5 receptor (mGluR5) function in a 6-hydroxydopamine (6-OHDA)-induced rat model of Parkinson's disease using four analogical PET ligands: 2-[11C]methyl-6-(2-phenylethynyl) pyridine ([11C]MPEP), 2-(2-(3-[11C]methoxyphenyl)ethynyl)pyridine ([11C]M-MPEP), 2-(2-(5-[11C]methoxypyridin-3-yl)ethynyl)pyridine ([11C]M-PEPy), and 3-[(2-[18F]methyl-1,3-thiazol-4-yl)ethynyl]pyridine ([18F]M-TEP). A total of 45 positron emission tomography (PET) imaging studies were conducted on nine male Sprague-Dawley rats within 4 to 6 weeks after unilateral 6-OHDA lesioning into the right medial forebrain bundle. The severity of the lesion was determined with [11C]CFT ([11C]2-β-carbomethoxy-3-β-(4-fluorophenyl)tropane), a specific and sensitive ligand for imaging dopamine transporter function. The binding potential (BP) images were processed on pixel-by-pixel basis by using a method of the distribution volume ratio with cerebellum as a reference tissue. The values for BP were determined on striatum, hippocampus, and cortex. [11C]CFT binding was decreased on the lesioned (right) striatum by 35.4% ± 13.4% compared with the intact left striatum, indicating corresponding loss of presynaptic dopamine terminals. On the same areas of the lesioned striatum, three of the four tested mGluR5 ligands showed enhanced binding characteristics. The average differences between the right and left striatum were 4.4% ± 6.5% ( P < 0.05) with [11C]MPEP, 0.1% ± 1.7% ( P > 0.05) with [11C]M-MPEP, 3.9% ± 4.6% ( P < 0.05) with [11C]M-PEPy, and 6.6% ± 2.7% ( P > 0.05) with [18F]M-TEP. The enhanced binding was also observed in the right hippocampus and cortex. These studies showed that glutamatergic neurotransmission might have a complementary role in dopaminergic degeneration, which can be evaluated by in vivo PET imaging.

scholarly journals Lack of Age-Dependent Decrease in Dopamine D3 Receptor Availability: A [11C]-(+)-PHNO and [11C]-Raclopride Positron Emission Tomography Study

2015 ◽  
Vol 35 (11) ◽  
pp. 1812-1818 ◽  
Author(s):  
Shinichiro Nakajima ◽  
Fernando Caravaggio ◽  
Isabelle Boileau ◽  
Jun K Chung ◽  
Eric Plitman ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Ventral Striatum ◽  
Emission Tomography ◽  
Ventral Pallidum ◽  
Binding Potential ◽  
Healthy Humans ◽  
Positron Emission ◽  
Age Dependent ◽  
Dopamine D3 ◽  
The Relationship

Positron emission tomography with antagonist radiotracers has showed that striatal dopamine D2/3 receptor (D2/3R) availability decreases with age. However, no study has specifically assessed whether D2/3R availability decreases with age in healthy persons as measured with agonist radiotracers. Moreover, it is unknown whether D3R availability changes with age in healthy humans. Thus, we explored the relationship between age and D2/3R availability in healthy humans using the D3 receptor (D3R)-preferential agonist radiotracer [11C]-(+)-PHNO ( n = 72, mean ± s.d. age = 40 ± 15, range = 18 to 73) and the antagonist [11C]-Raclopride ( n = 70, mean ± s.d. age = 40 ± 14, range = 18 to 73) (both, n = 33). The contribution of D3R to the [11C]-(+)-PHNO signal varies across regions of interest; the substantia nigra and hypothalamus represent D3R-specific regions, the ventral pallidum, globus pallidus, and ventral striatum represent D2/3R-mixed regions, and the caudate and putamen represent D2 receptor (D2R)-specific regions. With [11C]-(+)-PHNO, a negative correlation was observed between age and nondisplaceable binding potential (BPND) in the caudate ( r(70) = −0.32, P = 0.005). No correlations were observed in the other regions. With [11C]-Raclopride, negative correlations were observed between age and BPND in the caudate ( r(68) = −0.50, P < 0.001), putamen ( r(68) = −0.41, P < 0.001), and ventral striatum ( r(68) = −0.43, P < 0.001). In conclusion, in contrast with the age-dependent decrease in D2R availability, these findings suggest that D3R availability does not change with age.

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