The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Peter W. Kalivas - One of the best experts on this subject based on the ideXlab platform.
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Dopaminergic involvement in locomotion elicited from the ventral pallidum/substantia innominata.
Brain research, 1991Co-Authors: Mark C. Austin, Peter W. KalivasAbstract:Abstract Microinjection of the indirect GABAA antagonist, picrotoxin, or the μ opioid agonist, Tyr- d -Ala-Gly-NMe-Phe-Gly-ol (DAGO), into the ventral pallidum and substantia innominata (VP/SI) increases locomotor activity in rats. The VP/SI has direct and indirect projections to the region of the ventral mesencephalon containing dopamine perikarya, and to certain dopamine terminal fields, including the nucleus accumbens. Thus, it is possible that modulation of the mesocorticolimbic dopamine system by Pharmacological Stimulation in the VP/SI may play a role in the locomotor stimulant response. It was shown that pretreatment with dopamine receptor antagonists, either peripherally or microinjected into the nucleus accumbens significantly attenuated the motor stimulant effect of DAGO or picrotoxin injection into the VP/SI. Injection of either picrotoxin or DAGO into the VP/SI increased the levels of dopamine metabolites in the nucleus accumbens and prefrontal cortex. Thus, the motor stimulant response following Pharmacological Stimulation of the VP/SI appears to be mediated by increased dopamine neurotransmission via feedback mechanisms to the mesocorticolimbic dopamine system.
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dopaminergic involvement in locomotion elicited from the ventral pallidum substantia innominata
Brain Research, 1991Co-Authors: Mark C. Austin, Peter W. KalivasAbstract:Abstract Microinjection of the indirect GABAA antagonist, picrotoxin, or the μ opioid agonist, Tyr- d -Ala-Gly-NMe-Phe-Gly-ol (DAGO), into the ventral pallidum and substantia innominata (VP/SI) increases locomotor activity in rats. The VP/SI has direct and indirect projections to the region of the ventral mesencephalon containing dopamine perikarya, and to certain dopamine terminal fields, including the nucleus accumbens. Thus, it is possible that modulation of the mesocorticolimbic dopamine system by Pharmacological Stimulation in the VP/SI may play a role in the locomotor stimulant response. It was shown that pretreatment with dopamine receptor antagonists, either peripherally or microinjected into the nucleus accumbens significantly attenuated the motor stimulant effect of DAGO or picrotoxin injection into the VP/SI. Injection of either picrotoxin or DAGO into the VP/SI increased the levels of dopamine metabolites in the nucleus accumbens and prefrontal cortex. Thus, the motor stimulant response following Pharmacological Stimulation of the VP/SI appears to be mediated by increased dopamine neurotransmission via feedback mechanisms to the mesocorticolimbic dopamine system.
Mark C. Austin - One of the best experts on this subject based on the ideXlab platform.
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Dopaminergic involvement in locomotion elicited from the ventral pallidum/substantia innominata.
Brain research, 1991Co-Authors: Mark C. Austin, Peter W. KalivasAbstract:Abstract Microinjection of the indirect GABAA antagonist, picrotoxin, or the μ opioid agonist, Tyr- d -Ala-Gly-NMe-Phe-Gly-ol (DAGO), into the ventral pallidum and substantia innominata (VP/SI) increases locomotor activity in rats. The VP/SI has direct and indirect projections to the region of the ventral mesencephalon containing dopamine perikarya, and to certain dopamine terminal fields, including the nucleus accumbens. Thus, it is possible that modulation of the mesocorticolimbic dopamine system by Pharmacological Stimulation in the VP/SI may play a role in the locomotor stimulant response. It was shown that pretreatment with dopamine receptor antagonists, either peripherally or microinjected into the nucleus accumbens significantly attenuated the motor stimulant effect of DAGO or picrotoxin injection into the VP/SI. Injection of either picrotoxin or DAGO into the VP/SI increased the levels of dopamine metabolites in the nucleus accumbens and prefrontal cortex. Thus, the motor stimulant response following Pharmacological Stimulation of the VP/SI appears to be mediated by increased dopamine neurotransmission via feedback mechanisms to the mesocorticolimbic dopamine system.
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dopaminergic involvement in locomotion elicited from the ventral pallidum substantia innominata
Brain Research, 1991Co-Authors: Mark C. Austin, Peter W. KalivasAbstract:Abstract Microinjection of the indirect GABAA antagonist, picrotoxin, or the μ opioid agonist, Tyr- d -Ala-Gly-NMe-Phe-Gly-ol (DAGO), into the ventral pallidum and substantia innominata (VP/SI) increases locomotor activity in rats. The VP/SI has direct and indirect projections to the region of the ventral mesencephalon containing dopamine perikarya, and to certain dopamine terminal fields, including the nucleus accumbens. Thus, it is possible that modulation of the mesocorticolimbic dopamine system by Pharmacological Stimulation in the VP/SI may play a role in the locomotor stimulant response. It was shown that pretreatment with dopamine receptor antagonists, either peripherally or microinjected into the nucleus accumbens significantly attenuated the motor stimulant effect of DAGO or picrotoxin injection into the VP/SI. Injection of either picrotoxin or DAGO into the VP/SI increased the levels of dopamine metabolites in the nucleus accumbens and prefrontal cortex. Thus, the motor stimulant response following Pharmacological Stimulation of the VP/SI appears to be mediated by increased dopamine neurotransmission via feedback mechanisms to the mesocorticolimbic dopamine system.
Olivier Raineteau - One of the best experts on this subject based on the ideXlab platform.
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persistent wnt β catenin signaling determines dorsalization of the postnatal subventricular zone and neural stem cell specification into oligodendrocytes and glutamatergic neurons
Stem Cells, 2014Co-Authors: Kasum Azim, Bruno Fischer, Anahi Hurtadochong, Kalina Draganova, Claudio Cantu, Martina Zemke, Lukas Sommer, Arthur M Butt, Olivier RaineteauAbstract:In the postnatal and adult central nervous system (CNS), the subventricular zone (SVZ) of the forebrain is the main source of neural stem cells (NSCs) that generate olfactory neurons and oligodendrocytes (OLs), the myelinating cells of the CNS. Here, we provide evidence of a primary role for canonical Wnt/β-catenin signaling in regulating NSC fate along neuronal and oligodendroglial lineages in the postnatal SVZ. Our findings demonstrate that glutamatergic neuronal precursors (NPs) and oligodendrocyte precursors (OPs) are derived strictly from the dorsal SVZ (dSVZ) microdomain under the control of Wnt/β-catenin, whereas GABAergic NPs are derived mainly from the lateral SVZ (lSVZ) microdomain independent of Wnt/β-catenin. Transcript analysis of microdissected SVZ microdomains revealed that canonical Wnt/β-catenin signaling was more pronounced in the dSVZ microdomain. This was confirmed using the β-catenin-activated Wnt-reporter mouse and by Pharmacological Stimulation of Wnt/β-catenin by infusion of the specific glycogen synthase kinase 3β inhibitor, AR-A014418, which profoundly increased the generation of cycling cells. In vivo genetic/Pharmacological Stimulation or inhibition of Wnt/β-catenin, respectively, increased and decreased the differentiation of dSVZ-NSCs into glutamatergic NPs, and had a converse effect on GABAergic NPs. Activation of Wnt/β-catenin dramatically stimulated the generation of OPs, but its inhibition had no effect, indicating other factors act in concert with Wnt/β-catenin to fine tune oligodendrogliogenesis in the postnatal dSVZ. These results demonstrate a role for Wnt/β-catenin signaling within the dorsal microdomain of the postnatal SVZ, in regulating the genesis of glutamatergic neurons and OLs.
Yasutsugu Aihara - One of the best experts on this subject based on the ideXlab platform.
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changes of body temperature and thermoregulatory responses of freely moving rats during gabaergic Pharmacological Stimulation to the preoptic area and anterior hypothalamus in several ambient temperatures
Brain Research, 2005Co-Authors: Takayuki Ishiwata, Takehito Saito, Hiroshi Hasegawa, Toru Yazawa, Yasunori Kotani, Minoru Otokawa, Yasutsugu AiharaAbstract:Abstract Action of γ-aminobutyric acid (GABA) in the preoptic area and anterior hypothalamus (PO/AH) has been implicated to regulate body temperature (Tb). However, its precise role in thermoregulation remains unclear. Moreover, little is known about its release pattern in the PO/AH during active thermoregulation. Using microdialysis and telemetry techniques, we measured several parameters related to thermoregulation of freely moving rats during Pharmacological Stimulation of GABA in normal (23 °C), cold (5 °C), and hot (35 °C) ambient temperatures. We also measured extracellular GABA levels in the PO/AH during cold (5 °C) and heat (35 °C) exposure combined with microdialysis and high performance liquid chromatography (HPLC). Perfusion of GABAA agonist muscimol into the PO/AH increased Tb, which is associated with increased heart rate (HR), as an index of heat production in all ambient temperatures. Although tail skin temperature (Ttail) as an index of heat loss increased only under normal ambient temperatures, its response was relatively delayed in comparison with HR and Tb, suggesting that the increase in Ttail was a secondary response to increased HR and Tb. Locomotor activity also increased in all ambient temperatures, but its response was not extraordinary. Interestingly, thermoregulatory responses were different after perfusion of GABAA antagonist bicuculline at each ambient temperature. In normal ambient temperature conditions, perfusion of bicuculline had no effect on any parameter. However, under cold ambient temperature, the procedure induced significant hypothermia concomitant with a decrease in HR in spite of hyperactivity and increase of Ttail. It induced hyperthermia with the increase of HR but no additional change of Ttail in hot ambient temperature conditions. Furthermore, the extracellular GABA level increased significantly during cold exposure. Its release was lower during heat exposure than in a normal environment. These results indicate that GABA in the PO/AH is an important neurotransmitter for disinhibition of heat production and inhibition of heat loss under cold ambient temperature. It is a neurotransmitter for inhibition of heat production under hot ambient temperature.
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Changes of body temperature and thermoregulatory responses of freely moving rats during GABAergic Pharmacological Stimulation to the preoptic area and anterior hypothalamus in several ambient temperatures.
Brain research, 2005Co-Authors: Takayuki Ishiwata, Takehito Saito, Hiroshi Hasegawa, Toru Yazawa, Yasunori Kotani, Minoru Otokawa, Yasutsugu AiharaAbstract:Action of gamma-aminobutyric acid (GABA) in the preoptic area and anterior hypothalamus (PO/AH) has been implicated to regulate body temperature (T(b)). However, its precise role in thermoregulation remains unclear. Moreover, little is known about its release pattern in the PO/AH during active thermoregulation. Using microdialysis and telemetry techniques, we measured several parameters related to thermoregulation of freely moving rats during Pharmacological Stimulation of GABA in normal (23 degrees C), cold (5 degrees C), and hot (35 degrees C) ambient temperatures. We also measured extracellular GABA levels in the PO/AH during cold (5 degrees C) and heat (35 degrees C) exposure combined with microdialysis and high performance liquid chromatography (HPLC). Perfusion of GABA(A) agonist muscimol into the PO/AH increased T(b), which is associated with increased heart rate (HR), as an index of heat production in all ambient temperatures. Although tail skin temperature (T(tail)) as an index of heat loss increased only under normal ambient temperatures, its response was relatively delayed in comparison with HR and T(b), suggesting that the increase in T(tail) was a secondary response to increased HR and T(b). Locomotor activity also increased in all ambient temperatures, but its response was not extraordinary. Interestingly, thermoregulatory responses were different after perfusion of GABA(A) antagonist bicuculline at each ambient temperature. In normal ambient temperature conditions, perfusion of bicuculline had no effect on any parameter. However, under cold ambient temperature, the procedure induced significant hypothermia concomitant with a decrease in HR in spite of hyperactivity and increase of T(tail). It induced hyperthermia with the increase of HR but no additional change of T(tail) in hot ambient temperature conditions. Furthermore, the extracellular GABA level increased significantly during cold exposure. Its release was lower during heat exposure than in a normal environment. These results indicate that GABA in the PO/AH is an important neurotransmitter for disinhibition of heat production and inhibition of heat loss under cold ambient temperature. It is a neurotransmitter for inhibition of heat production under hot ambient temperature.
Hans F. Wehrl - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous PET/MR reveals changes in serotonin transporters and glucose metabolism with decreased functional connectivity of the rat brain during Pharmacological Stimulation.
The Journal of Nuclear Medicine, 2016Co-Authors: Tadashi Watabe, Mario Amend, Andre Thielcke, Jun Hatazawa, Bernd J. Pichler, Hans F. WehrlAbstract:407 Objectives Constant infusion of PET tracer can be used to detect the changes between baseline and Stimulation period in a single session, which is a suitable technique for the simultaneous PET/MR. The purpose of this study was to evaluate how a Pharmacological Stimulation using 3,4-methylenedioxymethamphetamine (MDMA) affects the serotonin transporter (SERT), glucose metabolism, and functional connectivity of the rat brain. Methods Normal Lewis rats (male, 16 weeks old, 295 ± 16 g, n=4) were studied using an integrated PET/MR scanner (7T MR with PET insert) under isoflurane anesthesia (1.5-2% with room air). After overnight fasting, simultaneous PET/MR acquisitions (100min) were performed with bolus and constant infusion of 11C-DASB (bolus 64 ± 18 MBq/0.48ml + 15µl/min, specific radioactivity = 49 ± 18 GBq/µmol) at day1 and with constant infusion of 18F-FDG (total: 117 ± 4.6 MBq/0.8ml) at day3. MDMA (3.2mg/kg), a potent serotonin releasing agent, was administered intravenously 40min after the scan start as a Pharmacological Stimulation. Echo planar imaging (EPI) sequences (TR: 2000ms, TE: 18ms) were continuously acquired during PET acquisition after anatomical T2 weighted imaging. PET data were reconstructed into 100 frames (1 min data per frame). All PET/MR data were co-registered using SPM12 and volumes of interest were placed using a rat brain atlas (PMOD 3.2). Glucose consumption was evaluated by 18F-FDG uptake using SUV, which was normalized by the injected dose at each time point. Non-displaceable binding potential (BPND) of 11C-DASB was calculated for the evaluation of SERT using the cerebellum gray matter as a reference region. Functional connectivity was evaluated by Pearson’s correlation maps of the functional MRI blood oxygen level dependent (fMRI BOLD) signal and compared among baseline condition (10-40min after the scan start), the early phase of MDMA Stimulation (40-70min), and the late phase (70-100min). SUV of 18F-FDG and BPND of 11C-DASB were compared between baseline condition and the late phase by paired t-test. Results 18F-FDG uptake was significantly increased in the whole brain (SUV: 1.24 ± 0.12 at baseline and 1.48 ± 0.05 in the late phase, p=0.019). Time activity curves of 18F-FDG showed an increased trend after MDMA Stimulation and a relatively large increase was observed in the striatum and the insular cortex (1.31 and 1.39 times uptake in the late phase compared to baseline, respectively). BPND of 11C-DASB also showed significant decrease in the whole brain (0.34 ± 0.27 at baseline and 0.19 ± 0.10 in the late phase, p=0.046). Among the brain regions, a large significant decrease of BPND (p Conclusions Pharmacological Stimulation using MDMA induced increased glucose consumption in the whole brain, decreased binding of SERT due to the inhibitory effect of MDMA, and decreased functional connectivity in the rat brain. Simultaneous PET/MR with constant infusion PET is a promising methodology to evaluate the combination of functional (fMRI) with metabolic (PET) connectivity mapping, cometomics, which allows new insights into brain function research.
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simultaneous pet mr reveals changes in serotonin transporters and glucose metabolism with decreased functional connectivity of the rat brain during Pharmacological Stimulation
The Journal of Nuclear Medicine, 2016Co-Authors: Tadashi Watabe, Mario Amend, Andre Thielcke, Jun Hatazawa, Bernd J. Pichler, Hans F. WehrlAbstract:407 Objectives Constant infusion of PET tracer can be used to detect the changes between baseline and Stimulation period in a single session, which is a suitable technique for the simultaneous PET/MR. The purpose of this study was to evaluate how a Pharmacological Stimulation using 3,4-methylenedioxymethamphetamine (MDMA) affects the serotonin transporter (SERT), glucose metabolism, and functional connectivity of the rat brain. Methods Normal Lewis rats (male, 16 weeks old, 295 ± 16 g, n=4) were studied using an integrated PET/MR scanner (7T MR with PET insert) under isoflurane anesthesia (1.5-2% with room air). After overnight fasting, simultaneous PET/MR acquisitions (100min) were performed with bolus and constant infusion of 11C-DASB (bolus 64 ± 18 MBq/0.48ml + 15µl/min, specific radioactivity = 49 ± 18 GBq/µmol) at day1 and with constant infusion of 18F-FDG (total: 117 ± 4.6 MBq/0.8ml) at day3. MDMA (3.2mg/kg), a potent serotonin releasing agent, was administered intravenously 40min after the scan start as a Pharmacological Stimulation. Echo planar imaging (EPI) sequences (TR: 2000ms, TE: 18ms) were continuously acquired during PET acquisition after anatomical T2 weighted imaging. PET data were reconstructed into 100 frames (1 min data per frame). All PET/MR data were co-registered using SPM12 and volumes of interest were placed using a rat brain atlas (PMOD 3.2). Glucose consumption was evaluated by 18F-FDG uptake using SUV, which was normalized by the injected dose at each time point. Non-displaceable binding potential (BPND) of 11C-DASB was calculated for the evaluation of SERT using the cerebellum gray matter as a reference region. Functional connectivity was evaluated by Pearson’s correlation maps of the functional MRI blood oxygen level dependent (fMRI BOLD) signal and compared among baseline condition (10-40min after the scan start), the early phase of MDMA Stimulation (40-70min), and the late phase (70-100min). SUV of 18F-FDG and BPND of 11C-DASB were compared between baseline condition and the late phase by paired t-test. Results 18F-FDG uptake was significantly increased in the whole brain (SUV: 1.24 ± 0.12 at baseline and 1.48 ± 0.05 in the late phase, p=0.019). Time activity curves of 18F-FDG showed an increased trend after MDMA Stimulation and a relatively large increase was observed in the striatum and the insular cortex (1.31 and 1.39 times uptake in the late phase compared to baseline, respectively). BPND of 11C-DASB also showed significant decrease in the whole brain (0.34 ± 0.27 at baseline and 0.19 ± 0.10 in the late phase, p=0.046). Among the brain regions, a large significant decrease of BPND (p Conclusions Pharmacological Stimulation using MDMA induced increased glucose consumption in the whole brain, decreased binding of SERT due to the inhibitory effect of MDMA, and decreased functional connectivity in the rat brain. Simultaneous PET/MR with constant infusion PET is a promising methodology to evaluate the combination of functional (fMRI) with metabolic (PET) connectivity mapping, cometomics, which allows new insights into brain function research.