(n.) The middle segment of the brain; the mesencephalon. See Brain.
Example Sentences:
(1) However, this inhibition was not found in rats treated with castor oil for 3 d. Moreover, 5-HT concentration in the midbrain significantly decreased in rats that acquired the adaptability for the occurrence of diarrhea.
(2) A train of conditioning stimuli to either of the midbrain nuclei produced inhibition of evoked population spikes recorded in the CA1 pyramidal cell layer of the hippocampus.
(3) Electrophysiological methods were used to determine changes in the neural representation of the binocular visual field at the paired midbrain optic tecta and in the tectal projection of pairs of corresponding retinal loci at various developmental points between these ages.
(4) Intracerebral injection of the GABAA agonists muscimol (1 nmol), isoguvacine (1 nmol) or THIP (1, 2 and 4 nmol) in rats with chemitrodes implanted in the dorsal midbrain central grey raised the threshold electrical current for inducing escape behaviour.
(5) Striking similarities were found between the functional pathways affected differentially by RET stimulation and well-defined cholinergic pathways which originate in the midbrain tegmentum.
(6) These responses were prominent in the rostral midbrain.
(7) Single neurons in the midbrain tegmentum of rats showed clear discriminatory responses to three tones announcing either food or water or no reinforcement.
(8) Stimulation using implanted electrodes in conscious rats, within the hypothalamic and midbrain areas described above, elicited typical 'flight' and 'escape' behaviour: thus, the localized regions from which the visceral alerting response is elicited contain neurones or nerve fibres integrating the whole defence-alerting response in the rat, as in other species.
(9) ruber, anterodorsolateral midbrain tegmentum, superior and inferior colliculi, pontine gray, cerebral peduncles, medial pontine reticular formation, raphe and vestibular nuclei did not affect the acoustic structure of the calls tested.
(10) This paper describes the distribution of histamine-like immunoreactivity in the midbrain and suboesophageal ganglion of the sphinx moth Manduca sexta.
(11) Parkinsonism in the present case may be due to the involvement of multiple neuronal circuits of the extrapyramidal system at the level of the midbrain to the thalamus.
(12) As a result the dipole of the wave V of auditory brainstem responses was found near the contralateral midbrain.
(13) In the latter tumors, a peculiar ataxic hemiparesis syndrome is produced by midbrain compression.
(14) Fewer, but still ample numbers, of SP-reactive axons are present also in the ventral tegmental and retrorubral areas of the midbrain tegmentum and in the ventral pallidum of the basal forebrain, but only sparse ME-reactive axons are present in these areas.
(15) In the investigation, the neocortex was represented by the frontal cortex (field 10), the old cortex by the hippocamp, the midbrain by black substance, and medulla oblongata by the inferior olive.
(16) The anxiolytic activity of serotonin agonists (buspirone, ipsapirone, campirone, caplapirone, 1-pyrimidinyl-piperazine) determined in rats on 3 experimental models of anxiety closely correlates with the degree of inhibition of impulse release of 3H-serotonin by electrically stimulated slices of the midbrain raphe dorsal nucleus (r = +0.85) but not the slices of the cerebral hemispheric cortex (r = +0.60) of the rats.
(17) The level of 5-HT was diminished in dorsal spinal cord and midbrain, whereas NE appeared unchanged.
(18) Movement-correlated firing was studied in 111 midbrain neurons recorded in freely behaving hamsters.
(19) These results suggest that different fibers with overlapping spatial distributions contribute to analgesia and vocalizations produced by midbrain stimulation.
(20) alpha-Fluoromethylhistidine, a histidine decarboxylase inhibitor, induced a significant depletion in the hypothalamic, midbrain, and cortical brain histamine amounts in 12- and 3-month-old rats.
Tegmentum
Definition:
(n.) A covering; -- applied especially to the bundles of longitudinal fibers in the upper part of the crura of the cerebrum.
Example Sentences:
(1) The effects of quinpirole and sulpiride on dopamine (DA), dihydroxyphenylacetic acid (DOPAC) and accumulation of dihydroxyphenylalanine (DOPA) after inhibition of DOPA decarboxylase were determined for the striatum and tegmentum of 11- and 17-day-old rat pups.
(2) A low-intensity thermally evoked tail avoidance reflex (LITETAR) was used to study changes in nociceptive response produced by local anesthetics and cobalt chloride microinjected into the dorsal posterior mesencephalic tegmentum (DPMT) of conscious rats.
(3) The neighbouring neocortical areas receive afferents neither from the mediodorsal nucleus of the thalamus nor from the ventral mesencephalic tegmentum; their catecholamine innervation is mainly confined to the superficial layers and appears to be of noradrenergic nature.
(4) One infant had a unilateral infarction in the medulla and another showed extensive gliosis in the brainstem tegmentum along with a large infarction in the region of the anterior cerebral artery.
(5) Striking similarities were found between the functional pathways affected differentially by RET stimulation and well-defined cholinergic pathways which originate in the midbrain tegmentum.
(6) Single neurons in the midbrain tegmentum of rats showed clear discriminatory responses to three tones announcing either food or water or no reinforcement.
(7) ruber, anterodorsolateral midbrain tegmentum, superior and inferior colliculi, pontine gray, cerebral peduncles, medial pontine reticular formation, raphe and vestibular nuclei did not affect the acoustic structure of the calls tested.
(8) Fewer, but still ample numbers, of SP-reactive axons are present also in the ventral tegmental and retrorubral areas of the midbrain tegmentum and in the ventral pallidum of the basal forebrain, but only sparse ME-reactive axons are present in these areas.
(9) In lampreys, the majority of HRP-labeled cells were located along the length of the brainstem reticular formation in the inferior, middle, and superior reticular nuclei of the medulla, mesencephalic tegmentum, and nucleus of the medial longitudinal fasciculus.
(10) Both hyperphagic and hyperdipsic animals had significantly lower concentrations of 5-HT in forebrain than rats which sustained similar cuts in the tegmentum which did not affect ingestive behavior.
(11) The topographical distribution of neuropeptide-containing cell bodies, fibers and terminals was studied in human parabrachial nuclei and the pontine tegmentum with immunohistochemical stainings.
(12) These results indicate that bilateral lesioning of the mesencephalic lateral tegmentum, which disrupts the milk-ejection response, could damage somatosensory projections originating from the dorsal horn of the spinal cord, the lateral cervical nucleus, the dorsal column nuclei and the sensory and spinal trigeminal nuclei.
(13) In bullfrogs, AVT concentrations were greater in males, compared to females, in the amygdala pars lateralis, optic tectum, and tegmentum.
(14) By means of an extracellular glass microelectrode method, unitary discharges synchronized with the grouping discharges in the pelvic vesical branch with a rhythm of 2.2-2.5 Hz were recorded from the pontine micturition center in the dorsolateral pontine tegmentum.
(15) Areas rich in [3H]-SP binding were located in the ventral telencephalon, in the entire hypothalamic and thalamic region, in the midbrain tegmentum, in the optic tectum, in the valvulla cerebelli and in the medulla oblongata.
(16) WGA-immunoreactive (-ir) neurons were identified in the DRN, PAG and lateral dorsal tegmentum (LDTg) after PF and CM injections.
(17) Smaller numbers of double-labeled neurons were located in the B9 cell group and the region of the lateral midbrain tegmentum.
(18) Degenerating fibers were observed to descend bilaterally through the midbrain, pontine, and medullary tegmentum to the vicinity of the principal sensory and motor nuclei of the trigeminal nerve.
(19) Using a retrograde tracer technique with horseradish peroxidase, we have identified the afferent connections to the visual cortex from the dorsolateral pontine tegmentum (locus coeruleus, nucleus parabrachialis medialis and nucleus parabrachialis lateralis) as well as from the dorsal raphe nucleus.
(20) Descending projections through the caudal dorsolateral pontine tegmentum and into the medial medullary reticular formation may be involved in the initiation of sensorimotor inhibition.