(n.) The middle segment of the brain; the midbrain. Sometimes abbreviated to mesen. See Brain.
Example Sentences:
(1) 5-HT containing terminals and fibers also were observed in the mesencephalon and appeared to run rostrally in the medial part of the medial forebrain bundle.
(2) Effects of noxious electrical tooth stimulations and intraarterial administration of bradykinin or inhalation of volatile anesthetics on substance P content in the diencephalon-mesencephalon, pons-medulla and the spinal cord were examined in the rat.
(3) In order to study the interactions between serotonergic mechanism and electrical stimulation of the mesencephalic central gray substance, rats were trained to lever-press for terminating aversive electric stimuli applied at the Periaqueductal gray and adjoining tectum of the mesencephalon.
(4) The activity of glycerophosphorylcholine phosphodiesterases was determined in the mesencephalon, diencephalon, cerebral hemispheres, cerebellum and olfactory bulb during postnatal development from P5 to P70 of rat brain.
(5) In addition, these amines caused a concurrent change in the release of ACh at perfusion loci in both thalamus and mesencephalon.
(6) Levels of acetylcholine were significantly elevated in the telencephalon and diencephalon + mesencephalon of rats killed by near-freezing during conditioned suppression of food-reinforced lever pressing, whereas levels of serotonin, dopamine, and norepinephrine were not altered.
(7) The onset of convulsions induced by these convulsants coincides with the fall in GABA content and GAD activity in the mesencephalon area, and in contrast, the cessation of the convulsions by PN supplement coincides with the recovery in both the parameters.
(8) However, a later component of the Cnf-AEP whose generation locus within the mesencephalon is unknown was modulated by bf stimulation.
(9) Six hours after treatment with AOAA the GABA levels in the cerebellum, the cortex, the ventral mesencephalon and the striatum.
(10) Responses of substantia nigra zona compacta neurons to nomifensine and amantadine were studied with intracellular recording techniques (current and voltage clamp) in in vitro slice preparation of rat mesencephalon.
(11) These results describe a novel neurochemical system within the rat basal ganglia that is regulated by dopaminergic innervation from the mesencephalon.
(12) The left vertebral angiography revealed an anteriovenous malformation in the mesencephalon mainly feeded by the thalamoperforate artery and the medial branch of the posterior choroidal artery.
(13) (1) In 27 animals microinjection of 25--100 ng of angiotensin II through chronic cannulae implanted in the preoptic region initiated drinking and in subsequent acute experiments influenced the spontaneous discharge rate of single neurons in the ipsi-lateral mesencephalon.
(14) Into the second week of embryo growth (E7-E15), GABA appears in the mesencephalon (E7) and the eye (E9-E10).
(15) Behavioral augmentation also has been shown with opioids such as morphine, and it is known that a stimulant action on dopaminergic perikarya in the ventromedial mesencephalon is critical to the development of behavioral sensitization to morphine.
(16) Since EKC- and NANM-induced cardiovascular and respiratory depression were not observed in conscious intact or chronic spinal dog, it is suggested that: 1) kappaergic system rostral to mesencephalon may play a role in counteracting these depressant effects of EKC; 2) sigma receptor-mediated tachypnea and tachycardia are dissociable; the tachypneic effect may be mediated through higher center while the medulla oblongata is involved in producing tachycardia.
(17) Critical points of changing axial orientation were identified at the mesencephalon, the Rathke pouch and third branchial arch, and with the hepato-cardio-respiratory complex split between the 2 axes.
(18) The local cerebral blood flow and oxygen tension in the brain cortex, the reticular formation of the mesencephalon and the posterior hypothalamus were studied in chronic experiments in non-anesthetized rabbits with experimentally induced myocardial infarction.
(19) The variation was in the order leptomeninges greater than hypothalamus greater than cerebral cortex = mesencephalon greater than cerebellum = brain stem.
(20) In the present work, using the indirect peroxidase-labelled antibody technique, we made a comparative study about the distribution of Met-enkephalin-like-immunoreactive (ELI)-cell bodies in rat mesencephalon; comparing animals that received colchicine into the lateral ventricle and animals that got the colchicine injected into different cerebral nuclei.
Pons
Definition:
(n.) A bridge; -- applied to several parts which connect others, but especially to the pons Varolii, a prominent band of nervous tissue situated on the ventral side of the medulla oblongata and connected at each side with the hemispheres of the cerebellum; the mesocephalon. See Brain.
Example Sentences:
(1) The pons, on the other hand, has a bioelectrical activity of its own during PS, i.e., the ponto-geniculo-occipital spikes (PGO).
(2) These included the noradrenergic, TH- and DBH-immunoreactive cell groups of the pons and medulla.
(3) + inf., pons + medulla), rCBF increased toward the control level gradually, and it completely recovered 60 min after recirculation.
(4) Injection of the tracer substance wheat germ agglutinin-horseradish peroxidase (WGA-HRP) directly into the basilar pontine nuclei using a ventral surgical approach resulted in the labeling of somata in many areas both rostral and caudal to the basilar pons.
(5) Urea decreased and valine increased in the TD medulla-pons.
(6) Recently, direct pathways from the dorsolateral pons to the ON, probably involved in supraspinal micturition control, have been reported (Holstege et al., 1986).
(7) In the pons, PRV labeled neurons were found bilaterally in the locus ceruleus, subceruleus region, and parabrachial complex.
(8) P3.1 and P3.8 were identified only as farfield potentials in intracranial recordings from the pons and more rostral regions.
(9) Computed tomography showed a lesion in the pons, and seven months later he was found to have metastatic adenocarcinoma.
(10) Weaker linkage between the CF locus and the locus for the serum enzyme activity marker paraoxonase (PON) was detected, theta = 0.18, zeta = 0.76.
(11) In the medulla and pons the ir appeared as from E12.
(12) Pons-Tortella et al reported the sparing of this nucleus in acute anterior poliomyelitis.
(13) Effects of noxious electrical tooth stimulations and intraarterial administration of bradykinin or inhalation of volatile anesthetics on substance P content in the diencephalon-mesencephalon, pons-medulla and the spinal cord were examined in the rat.
(14) Synchronization of phasic bursts was consistently observed between simultaneously recorded structures and this, along with the time course of early increments in SW was consistent with the notion that mesencephalic reticular activity is controlled by leading influences from the pons.
(15) Specifically, a decrease in the central conduction times was noted for the I-III interpeak interval, suggesting neurophysiologic dysfunction in the area of the pons and cerebellum.
(16) Among them, two patients had deformities of the pons.
(17) This study examines the effects of styrene oxide, a reactive metabolite of the neurotoxic solvent styrene, on GSH metabolism in six regions of the rat brain (cortex, cerebellum, medulla-pons, hippocampus, striatum and hypothalamus).
(18) The course of the fiber pathways to pons from parasensory association areas in the rhesus monkey was investigated by injection of tritiated amino acids and the technique of autoradiography.
(19) 1 The ability of chlorpromazine to antagonize the effects of iontophoretic application of (+)-amphetamine to single neurones in the medulla and lower pons of anaesthetized rats has been studied.
(20) Noradrenaline concentration was elevated in the brain stem, particularly in the pons, and decreased in the cerebral cortex and the spinal cord while in the cerebellum, the effects were dependent on the mode of administration.