What's the difference between mesencephalon and metencephalon?
Mesencephalon
Definition:
(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.
Metencephalon
Definition:
(n.) The posterior part of the brain, including the medulla; the afterbrain. Sometimes abbreviated to meten.
Example Sentences:
(1) The metencephalon differentiated as a cerebellum in the telencephalon.
(2) Proenkephalin-containing perikarya were located in all major subdivisions of the brain except the metencephalon.
(3) Using an anti-tyrosine hydroxylase antiserum, the whole of catecholaminergic perikarya of the myelencephalon and metencephalon of the sheep were visualized immunocytochemically.
(4) The first histamine-immunoreactive neurons were seen on embryonic day 13 in the border of mesencephalon and metencephalon.
(5) The midbrain itself is required for normal development of the metencephalon.
(6) Brainstems of 14-15 days old rat embryos were removed and the area located between the mesencephalic flexure and the caudal portion of metencephalon was dissected and mechanically dissociated to single cells.
(7) In mammals, cells in the superior rhombic lip and dorsal part of the dorsal lamina of the metencephalon are said to proliferate to form two rounded swellings, the rudiments of the cerebellum.
(8) Rostral mesencephalon and rostral metencephalon have been more easily influenced by environmental factors than their caudal counterparts, suggesting that regions providing instructive positional factors exist within the 2-day-old germinative neuroepithelium.
(9) These results demonstrate that at least some regions of the germinative neuroepithelium from either metencephalon, mesencephalon, and diencephalon are still pluripotent in the 2-day-old avian embryo and that their fate seems to be under the influence of the surrounding structures.
(10) E9.5 brain fragments containing metencephalon and mesencephalon were isolated, explanted on Nucleopore filters and cultured in the absence or presence of antibodies to E-cadherin.
(11) We found that E-cadherin (uvomorulin) is transiently expressed in restricted regions of the metencephalon, mesencephalon and diencephalon of mouse embryonic brain.
(12) The matrix cells in the di-, mes- and metencephalon appeared less or not at all affected by maternal hypoxia.
(13) In some mammals, mast cells were also numerous in the stroma of the telencephalic choroid plexuses (chimpanzee, squirrel monkey), the putamen and the claustrum (chimpanzee), the subfornical organ (pack rat, tiger, chimpanzee), the olfactory peduncles (hooded rat, albino rat), the stroma of the diencephalic choroid plexus (lion, chimpanzee, squirrel monkey), the pineal organ (chimpanzee, squirrel monkey), some nuclei of the hypothalamus (tiger), the infundibulum (hooded rat, tiger, fox) the area postrema (pack rat, chinchilla, lion, spider monkey, chimpanzee, fox) and some nuclei and tracts of the metencephalon and the myelencephalon (tiger).
(14) In both genera, there were numerous 5-HT+ and LENK+ fusiform cells paralleling the ventral surface of the metencephalon and myelencephalon.
(15) High concentrations of total radioactivity were observed by autoradiography in the midbrain and hindbrain (mesencephalon, metencephalon, and myelencephalon) and spinal cord, but not in the forebrain.
(16) Control embryos containing intact notochords expressed Engrailed-2 protein within the neural tube and in a subset of the neural crest and overlying surface ectoderm at the future mesencephalon and cranial metencephalon levels.
(17) At this stage, in the central nervous system, mesencephalic trigeminal neurons are also E1.9 and B30 positive as they migrate to their final location in the rostral metencephalon.
(18) The prosencephalon did not differentiate into the cerebellum when transplanted into the metencephalon, although previous study showed that the prosencephalon has the capacity to differentiate into the optic tectum.
(19) These results suggest that centres above the metencephalon do not exert any tonic effects on the cell bodies of the olivocochlear pathways that result in tonic effects at the cochlea.
(20) In addition, putative A1, A2, A5, A7 (noradrenergic) groups were found in the metencephalon and myelencephalon.