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S3-3 Mapping functional organization of human brain using positron emission tomography
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s3-3 MAPPING FUNCTIONAL ORGANIZATION OF HUMAN BRAIN USING POSITRON EMISSION TOMOGRAPHY. RYUTA KAWASHIMA Department of Nuclear Medicine & Radiology, IDAC, Tohoku Univ.
A tight coupling of changes in neuronal activity to regional cerebral blood flow (rCBF) changes has been demonstrated previously. Positron emission tomography (PET) techniques for mapping the functional organization of the human brain, in which rCBF is used to map the activity of neurons and synapses, have now achieved sufficient spatial resolution to identify specific sites of activation in relation to the cognitive tasks. Although these techniques have been carried many limitations and limitations in interpretations, there are a large number of literatures which directly attempt to understand relationships between cognition and brain structures. s3-4 MAPPING OF HISTAMINE RECEPTORS IN THE HUMAN BRAINS BY PET KAZUHIKO YANAI AND TAKEHIKO WATANABE. Department of Pharmacology I, Tohoku University School of Medicine
Histamine is now widely recognized as a neurotransmitter acting through the three specific receptors denoted as HI, HP,and H3 receptors. Cerebrospinal fluids and autopsied human brains were mainly used for investigation of neurotransmitters and receptors in humans. Positron emission tomography (PET) is a non-invasive method to measure neurotransmission in the living human brain, We have labeled several [1’C]-labeled histamine antagonists for visualizing histamine receptors in human brains. Using the PET techniques, we are now measuring histamine HI receptors in several neurological disorders and are evaluating the incidence of central side effects caused by antihistaminics. An outline of our works on the HI receptors will be presented and a future perspective for imaging specific neurotransmission will be also discussed. s3-5 IMAGING THE BRAIN OPIOID SYSTEM IN REWARD: COCAINE ABUSE AND DEPRESSION J.JAMES FROST, M.D., PH.D. Professorof Radiologyand Neuroscience,The Johns Hopkins UniversitySchool of Medicine The endogenous brain opioid system is believed to play and important role in mediating reward mechanisms. For example, opioid innervation is high in many limbic regions and the reinforcing actions of many drugs of abuse are thought to be mediated via endogenous opioid peptides and opioid receptors. For example, the psycho stimulant cocaine is known to increase the release of endogenous opioid peptides and the use of opioid antagonists can block reinforcing effects of cocaine. Depression is a disorder associated with decreased reward and mood alterations. Using PET and C-l 1 carfentinal we have investigated abnormalities in regional brain m opioid receptor binding in cocaine abusers and patients with unipolar depression. In both disorders, there are increases in regional opioid receptor binding that correlate with behavioral measures of craving in cocaine abuse and mood in depression. In addition, the response to anti-depressant therapy in depression is related to changes in regional m opioid receptor binding. These results demonstrate that PET can be used to investigate the role of opioid receptors in altered mechanisms of reward in the human brain.
s3-3 MAPPING FUNCTIONAL ORGANIZATION OF HUMAN BRAIN USING POSITRON EMISSION TOMOGRAPHY. RYUTA KAWASHIMA Department of Nuclear Medicine & Radiology, IDAC, Tohoku Univ.
A tight coupling of changes in neuronal activity to regional cerebral blood flow (rCBF) changes has been demonstrated previously. Positron emission tomography (PET) techniques for mapping the functional organization of the human brain, in which rCBF is used to map the activity of neurons and synapses, have now achieved sufficient spatial resolution to identify specific sites of activation in relation to the cognitive tasks. Although these techniques have been carried many limitations and limitations in interpretations, there are a large number of literatures which directly attempt to understand relationships between cognition and brain structures. s3-4 MAPPING OF HISTAMINE RECEPTORS IN THE HUMAN BRAINS BY PET KAZUHIKO YANAI AND TAKEHIKO WATANABE. Department of Pharmacology I, Tohoku University School of Medicine
Histamine is now widely recognized as a neurotransmitter acting through the three specific receptors denoted as HI, HP,and H3 receptors. Cerebrospinal fluids and autopsied human brains were mainly used for investigation of neurotransmitters and receptors in humans. Positron emission tomography (PET) is a non-invasive method to measure neurotransmission in the living human brain, We have labeled several [1’C]-labeled histamine antagonists for visualizing histamine receptors in human brains. Using the PET techniques, we are now measuring histamine HI receptors in several neurological disorders and are evaluating the incidence of central side effects caused by antihistaminics. An outline of our works on the HI receptors will be presented and a future perspective for imaging specific neurotransmission will be also discussed. s3-5 IMAGING THE BRAIN OPIOID SYSTEM IN REWARD: COCAINE ABUSE AND DEPRESSION J.JAMES FROST, M.D., PH.D. Professorof Radiologyand Neuroscience,The Johns Hopkins UniversitySchool of Medicine The endogenous brain opioid system is believed to play and important role in mediating reward mechanisms. For example, opioid innervation is high in many limbic regions and the reinforcing actions of many drugs of abuse are thought to be mediated via endogenous opioid peptides and opioid receptors. For example, the psycho stimulant cocaine is known to increase the release of endogenous opioid peptides and the use of opioid antagonists can block reinforcing effects of cocaine. Depression is a disorder associated with decreased reward and mood alterations. Using PET and C-l 1 carfentinal we have investigated abnormalities in regional brain m opioid receptor binding in cocaine abusers and patients with unipolar depression. In both disorders, there are increases in regional opioid receptor binding that correlate with behavioral measures of craving in cocaine abuse and mood in depression. In addition, the response to anti-depressant therapy in depression is related to changes in regional m opioid receptor binding. These results demonstrate that PET can be used to investigate the role of opioid receptors in altered mechanisms of reward in the human brain.