Periaqueductal Grey
Mostrando 13-20 de 20 artigos, teses e dissertações.
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13. Differential responses of lateral and ventrolateral rat periaqueductal grey neurones to noradrenaline in vitro.
1. The action of noradrenaline on the membrane properties of rat periaqueductal grey (PAG) neurones was examined using intracellular recordings in brain slices maintained in vitro. Morphological properties and the anatomical location of neurones were characterized by use of intracellular staining within biocytin. 2. Noradrenaline (0.3-100 microM) depolarized
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14. Presynaptic inhibitory action of opioids on synaptic transmission in the rat periaqueductal grey in vitro.
1. The actions of opioids on synaptic transmission in rat periaqueductal grey (PAG) neurones were examined using whole-cell patch-clamp recordings in brain slices. 2. Methionine enkephalin (ME; 10 microM) inhibited evoked GABAergic inhibitory postsynaptic currents (IPSCs) by 57%, non-NMDA excitatory postsynaptic currents (EPSCs) by 60%, and NMDA EPSCs by 43%
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15. Differentiation of delta and mu opiate receptor localizations by light microscopic autoradiography.
We have observed two discrete populations of opiate receptors that are differently localized in rat brain. Morphine-like (mu) receptors, labeled by 125I-labeled [D-Ala-2MePhe4Met(O)5-ol]enkephalin, are concentrated selectively in lamina IV of the cerebral cortex, certain thalamic nuclei, and the periaqueductal grey, while delta receptors, labeled by 125I-lab
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16. Properties and ionic basis of the action potentials in the periaqueductal grey neurones of the guinea-pig.
1. Action potentials of neurones of the ventral part of the guinea-pig periaqueductal grey (PAG) were studied by intracellular recording in a mesencephalic slice preparation maintained in vitro. 2. Fast spikes spontaneously fired last 2.8 +/- 0.6 ms (mean +/- S.D.) and have an amplitude of 72.3 +/- 5.3 mV (n = 28). The neurones could be antidromically activa
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17. Facilitation of the arterial baroreflex by the preoptic area in anaesthetized rats.
1. Activation of cell bodies in the ventrolateral part of the midbrain periaqueductal grey matter (PAG) facilitates the arterial baroreflex via the nucleus raphe magnus. The facilitatory effects of stimulation within the hypothalamus on the arterial baroreflex and their relation to the PAG and nucleus raphe magnus were studied in urethane- and chloralose-ana
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18. Effect of midbrain stimulations on thermoregulatory vasomotor responses in rats.
1. Efferent projections eliciting vasodilatation when the preoptic area is warmed were investigated by monitoring tail vasomotor responses of ketamine-anaesthetized rats when brain areas were stimulated electrically (0.2 mA, 200 microseconds, 30 Hz) or with the excitatory amino acid D,L-homocysteic acid (1 mM, 0.3 microliter). 2. Both stimulations elicited v
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19. Three scrapie prion isolates exhibit different accumulation patterns of the prion protein scrapie isoform.
To investigate the molecular basis of prion diversity, we inoculated transgenic mice expressing the Syrian hamster prion protein (PrP) with three distinct prion isolates. We compared the three isolates designated Sc237, 139H, and Me7H in Tg(SHaPrP)7 mice with clinical signs of scrapie because the incubation times with these mice are considerably shorter than
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20. Supraspinal morphine and descending inhibitions acting on the dorsal horn of the rat.
1. Recordings were made from thirty-nine convergent neurones in the lumbar enlargement of the rat spinal cord. These neurones were activated by both innocuous and noxious stimuli applied to their excitatory receptive fields located on the extremity of the ipsilateral hind paw. Transcutaneous application of suprathreshold 2 ms square-wave pulses to the centre