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Use of procalcitonin and white blood cells as combined predictors of infection in cardiac surgery patients. Crit Care 2014. [PMCID: PMC4068649 DOI: 10.1186/cc13405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Quality of life and predictive factors in patients undergoing assisted reproduction techniques. Eur J Obstet Gynecol Reprod Biol 2013; 167:176-80. [PMID: 23347604 DOI: 10.1016/j.ejogrb.2012.12.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2012] [Revised: 08/28/2012] [Accepted: 12/13/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To evaluate the quality of life (QOL) of a cohort of women undergoing assisted reproduction techniques (ART), to compare two QOL questionnaires [Short Form 36 (SF36) and FertiQoL], and to identify the predictive factors related to QOL. STUDY DESIGN Women who received infertility medication from a hospital pharmacist during a one-year period were included in this study. Two standardized validated questionnaires - FertiQoL and SF36 - were used. Multivariate analyses were used to assess predictive factors for QOL. RESULTS Sixty-one women participated in this study. Median QOL scores ranged from 58 to 100. Comparisons between the two questionnaires revealed lower QOL scores when using FertiQoL. Most correlations between the questionnaires were positive, and significant for the majority of SF36 mental dimensions. The major predictors of QOL were: accompanied to the pharmacist's visit by partner, nationality, ART (in vitro fertilization or artificial insemination), employment status (employed or unemployed), tobacco consumption, age, number of cycles, infertility factor and treatment results (pregnancy, no pregnancy or treatment cancellation). CONCLUSIONS FertiQoL examines dimensions such as partner and social relationships. As such, it is recommended that FertiQoL should be used together with a short version of SF36 to investigate QOL among patients undergoing ART.
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Abstract
The xylem-limited bacterium Xylella fastidosa causes the widely disseminated citrus variegated chlorosis disease (CVC). In Brazil, CVC has been known for more than 20 years and affects only sweet orange. Lime and mandarin have remained free of symptoms despite the high inoculum pressure. Knowing the mechanisms underlying this apparent resistance is important to devise new disease control strategies. The reaction of commercial sweet orange ('Caipira', 'Natal', 'Pêra', and 'Valencia'), lime (Mexican and Persian), mandarin ('Cleopatra', 'Cravo', 'Ponkan', and 'Sunki'), and the acid citrus species Rangpur to X. fastidiosa was compared in artificially inoculated seedlings, which were assessed for symptom expression, pathogen isolation, and the amount of apparently occluded xylem vessels in cross-sectioned leaf petioles. Only the sweet orange expressed typical CVC symptoms, varying from 53.8% in Valencia to 63.0% in Caipira. Average percentages of positive isolations (pi) and occluded vessels (ov) were higher in sweet orange (pi= 59.2 to 75.0; ov = 10.7 to 25.8) than mandarin (pi = 2.3 to 16.3; ov = 1.4 to 4.0), lime (pi = 0 to 5.4; ov = 0 to 2.1), or Rangpur (pi = 1,9; ov = 1.1). There were no obvious differences in xylem anatomy among all citrus varieties, suggesting that the mechanisms of resistance to CVC are not related to any physical variation in xylem structure.
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176. Neumonía asociada a ventilación mecánica tras cirugía cardíaca mayor: Impacto en la mortalidad al año. CIRUGIA CARDIOVASCULAR 2012. [DOI: 10.1016/s1134-0096(12)70399-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Single-cell recordings: a method for investigating the brain's activation pattern during exercise. Methods 2008; 45:262-70. [PMID: 18572026 DOI: 10.1016/j.ymeth.2008.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 05/21/2008] [Accepted: 05/22/2008] [Indexed: 10/21/2022] Open
Abstract
The precision of human movements to generate skills as accurate as the exercises performed by athletes are the consequence of a long and complex learning process. These processes involve a great amount of the nervous system's structures. Electrophysiological techniques have been largely used to highlight brain functions related to the control of these kinds of movements. These methods cover invasive and non-invasive techniques which have been applied to humans and experimental animals. We describe here electrophysiological techniques that are used in behaving animals. Especially, we will focus on the analysis and results obtained from single-cell recording in the prefrontal cortex to explain the relationship between single neuronal activity and movement during locomotion. In addition, we will show how, analyzing these results, that we can characterize the integrative role of neurons involved in the control of locomotion. The objective is to demonstrate single-cell recording techniques as suitable methods to study, in experimental animals, the brain's activation pattern during exercise.
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[The nutritional status of patients with colorectal cancer undergoing chemotherapy]. FARMACIA HOSPITALARIA 2008; 32:35-37. [PMID: 18426700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
OBJECTIVE Determine the nutritional status of patients with colorectal cancer undergoing chemotherapy and assess how many patients could benefit from nutrition facts. METHOD Patients of both sexes aged over the age of 18 with colorectal cancer who were receiving chemotherapy between March and April 2005 were included. The nutritional status of these patients was evaluated using the method "Patient-Generated Subjective Global Assessment" (PG-SGA). According to this questionnaire, the patients were classified in one of four levels of intervention (a) no intervention required; b) nutrition education; c) nutritional intervention; d) critical intervention) and into one of three nutritional status (well-nourished, moderately malnourished or severely malnourished). RESULTS All the patients with colorectal cancer receiving chemotherapy during the two months indicated (33 patients): 9.1% were in stage II of the disease, 21.2% in stage III and 69.7% in stage IV. The 69.7% was receiving cytostatics associated with moderate risk of malnutrition while 30.3% received low-risk chemotherapy. 57.6% of the patients were well-nourished. However, the intervention was critical in 42.4% of the patients. CONCLUSIONS The majority of the patients studied require some type of nutritional act, although not all of them suffer from malnutrition.
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β-Amyloid peptide25–35 depresses excitatory synaptic transmission in the rat basolateral amygdala “in vitro”. Neurobiol Aging 2005; 26:419-28. [PMID: 15653170 DOI: 10.1016/j.neurobiolaging.2004.05.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2003] [Revised: 01/12/2004] [Accepted: 05/28/2004] [Indexed: 11/17/2022]
Abstract
The effects of beta-amyloid peptide25-35 on resting membrane potential, spontaneous and evoked action potential and synaptic activity have been studied in basolateral amygdaloid complex on slices obtained from adult rats. Intracellular recordings reveal that perfusion with beta-amyloid peptide25-35 at concentrations of 400 nM and less did not generate any effect on resting membrane potential. However, concentrations in the range of 800-1200 nM produced an unpredictable effect, depolarization and/or hyperpolarization, which were blocked by tetrodotoxin or 6-cyano-7-nitroquinoxaline-2,3-dione+D-(-)-2-amino-5-phosphonopentanoic acid together with bicuculline. Excitatory and inhibitory evoked responses mediated by glutamic acid or gamma-aminobutyric acid decreased in amplitude after beta-amyloid peptide25-35 perfusion. Additionally, results obtained using the paired-pulse protocol offer support for a presynaptic mode of action. To determine which type of receptors and/or channels are involved in the presynaptic mechanism of action, a specific blocker of alpha-7 nicotinic receptors (methyllycaconitine citrate) or L-type calcium channel blockers (calcicludine or nifedipine) were used. beta-amyloid petide25-35 decreased excitatory postsynaptic potentials amplitude in control conditions and also in slices permanently perfused with methyllycaconitine citrate. However, this effect was blocked in slices perfused with calcicludine or nifedipine suggesting the involvement of the L-type calcium channels. On the whole, these experiments provide evidence that beta-amyloid peptide25-35 affects neurotransmission in basolateral amygdala and its action is mediated through L-type calcium channels.
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Functional recovery of skilled forelimb use in rats obliged to use the impaired limb after grafting of the frontal cortex lesion with homotopic fetal cortex. Neurobiol Learn Mem 2001; 75:274-92. [PMID: 11300734 DOI: 10.1006/nlme.2000.3979] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The long-term effect of transplanting embryonic frontal cortex into a unilateral frontal cortex lesion has been studied in adult rats. Before surgery, activity in an open field, muscular strength of both forelimbs, and performance in a paw-reaching-for-food task were scored in 26 rats. In 21 animals a unilateral cortex lesion was then made in the forelimb motor area of the hemisphere contralateral to the preferred paw in the paw-reaching-for-food task, while the other 5 animals were sham-operated. On retesting, the lesion animals changed the preferred paw. A solid homotopic transplant of embryonic tissue (embryonic day 17) was then placed in the lesion cavity in 11 of the lesion rats. Three months later neither lesion alone nor lesion plus transplantation affected open field behavior and muscular strength, but the lesion permanently affected performance in the paw-reaching-for-food task, as shown by a change of preferred paw and a functional deficit in the paw contralateral to the lesion. Transplantation ameliorated the deficits caused by the lesion, but this was only evident when animals were forced to reach with the paw contralateral to the lesion plus transplant. The behavioral results were independent of the size of the lesion and graft. Connections between graft and host tissue were studied by means of the fluorescent tracer 1,1'-dioctadecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate (DiI). A dense array of labeled fibers was found in the host cortex adjacent to the transplant. The results suggest that functional recovery depends on grafting but is only evident when the animal is obliged to use the affected limb.
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Abstract
Intracellular recordings in slice preparations of the basolateral amygdala were used to test which excitatory amino acid receptors mediate the excitatory postsynaptic potentials due to stimulation of the external capsule. These recordings were also used to examine the action of muscarinic agonists on the evoked excitatory potentials. Intracellular recordings from amygdaloid pyramidal neurons revealed that carbachol (2-20 microM) suppressed, in a dose-dependent manner, excitatory postsynaptic responses evoked by stimulation of the external capsule (EC). This effect was blocked by atropine. The estimated effective concentration to produce half-maximal response (EC(50)) was 6.2 microM. Synaptic suppression was observed with no changes in the input resistance of the recorded cells, suggesting a presynaptic mechanism. In addition, the results obtained using the paired-pulse protocol provided additional support for a presynaptic action of carbachol. To identify which subtype of cholinergic receptors were involved in the suppression of the EPSP, four partially selective muscarinic receptor antagonists were used at different concentrations: pirenzepine, a compound with a similar high affinity for muscarinic M1 and M4 receptors; gallamine, a noncompetitive antagonist for M2; methoctramine, an antagonist for M2 and M4; and 4-diphenylacetoxy-N-methylpiperidine, a compound with similar high affinity for muscarinic receptors M1 and M3. None of them independently antagonized the suppressive effect of carbachol on the evoked EPSP completely, suggesting that more than one muscarinic receptor subtype is involved in the effect. These experiments provide evidence that in the amygdala muscarinic agonists block the excitatory synaptic response, mediated by glutamic acid, by acting on several types of presynaptic receptors.
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Muscarinic activation of a non-selective cationic conductance in pyramidal neurons in rat basolateral amygdala. Neuroscience 1999; 88:159-67. [PMID: 10051197 DOI: 10.1016/s0306-4522(98)00210-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In the present study, a cationic membrane conductance activated by the acetylcholine agonist carbachol was characterized in vitro in neurons of the basolateral amygdala. Extracellular perfusion of the K+ channel blockers Ba2+ and Cs+ or loading of cells with cesium acetate did not affect the carbachol-induced depolarization. Similarly, superfusion with low-Ca2+ solution plus Ba2+ and intracellular EGTA did not affect the carbachol-induced depolarization, suggesting a Ca2+-independent mechanism. On the other hand, the carbachol-induced depolarization was highly sensitive to changes in extracellular K+ or Na+. When the K+ concentration in the perfusion medium was increased from 4.7 to 10 mM, the response to carbachol increased in amplitude. In contrast, lowering the extracellular Na+ concentration from 143.2 to 29 mM abolished the response in a reversible manner. Results of coapplication of carbachol and atropine, pirenzepine or gallamine indicate that the carbachol-induced depolarization was mediated by muscarinic cholinergic receptors, but not the muscarinic receptor subtypes M1, M2 or M4, specifically. These data indicate that, in addition to the previously described reduction of a time- and voltage-independent K+ current (IKleak), a voltage- and time-dependent K+ current (IM), a slow Ca2+-activated K+ current (sIahp) and the activation of a hyperpolarization-activated inward rectifier K+ current (IQ), carbachol activated a Ca2+-independent non-selective cationic conductance that was highly sensitive to extracellular K+ and Na+ concentrations.
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Abstract
We produced and characterized two monoclonal antibodies, termed 1.9.E and 4.11.C, that specifically recognize olfactory bulb ensheathing glia. Both antibodies were generated using the olfactory nerve layer (ONL) of newborn rat olfactory bulbs (P0, P1) as immunogens. The specificity of these antibodies was tested by immunofluorescence techniques on tissue sections and cultures of adult and neonatal rat olfactory bulbs, and by Western blot analysis. 1.9.E labeled the ONL and glomerular layer of the olfactory bulb (OB) of adult rats. In newborn rats, 1.9.E immunostained ensheathing cells from the ONL and peripheral olfactory fascicles. Furthermore, 1.9.E reacted with some processes of the radial glia in the periventricular germinal layer of the newborn rat. Although 4.11.C also specifically labeled ensheathing cells in the adult OB, it did not stain any cell type in the ONL of newborn rats. The lack of double labeling with either 1.9.E or 4.11.C and anti-olfactory marker protein (OMP) antibody, a specific marker for olfactory axons, indicated that none of the monoclonals recognized olfactory axons. Double immunostaining of adult OB cultures with 1.9.E or 4.11.C and anti-p75-nerve growth factor receptor revealed that both antibodies specifically recognized ensheathing glia in those cultures. Filaments were strongly labeled throughout the entire cytoplasm of ensheathing cells, suggesting that 1.9.E and 4.11.C immunoreacted with ensheathing glia cytoskeleton. 4.11.C stained a few Schwann cells in adult sciatic nerve sections. Moreover, 4.11.C immunostained cortical astrocyte cultures from newborn rats (P1). In Western blot analysis both antibodies recognized a major component, migrating with an apparent molecular weight of 60 kDa, from olfactory nerve and glomerular layer (ONGL) extracts of adult and neonatal rats. The pattern of immunoreactivity of 1.9.E and 4.11.C antibodies suggest that both antibodies are specific markers for olfactory ensheathing glia in the adult rat central nervous system (CNS).
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Cholinergic responses of morphologically and electrophysiologically characterized neurons of the basolateral complex in rat amygdala slices. Neuroscience 1997; 78:731-43. [PMID: 9153654 DOI: 10.1016/s0306-4522(96)00614-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The electrophysiological properties, the response to cholinergic agonists and the morphological characteristics of neurons of the basolateral complex were investigated in rat amygdala slices. We have defined three types of cells according to the morphological characteristics and the response to depolarizing pulses. Sixty-six of the recorded cells (71%) responded with two to three action potentials, the second onwards having less amplitude and longer duration (burst). In a second group, consisting of 21 cells (22%), the response to depolarization was a train of spikes, all with the same amplitude (multiple spike). Finally, seven neurons (7%) showed a single action potential (single spike). Burst response and multiple-spike neurons respond to the cholinergic agonist carbachol (10-20 microM) with a depolarization that usually attained the level of firing. This effect was accompanied by decreased or unchanged input membrane resistance and was blocked by atropine (1.5 microM). The depolarizing response to superfusion with carbachol occurred even when synaptic transmission was blocked by tetrodotoxin, indicating a direct effect of carbachol. Similarly, the depolarization by carbachol was still present when the M-type conductance was blocked by 2 mM Ba2+. The carbachol-induced depolarization was prevented by superfusion with tetraethylammonium (5 mM). Injection of biocytin into some of the recorded cells and subsequent morphological reconstruction showed that "burst" cells have piriform or oval cell bodies with four or five main dendritic trunks; spines are sparse or absent on primary dendrites but abundant on secondary and tertiary dendrites. This cellular type corresponds to a pyramidal morphology. The "multiple-spike" neurons have oval or fusiform somata with four or five thick primary dendritic trunks that leave the soma in opposite directions; they have spiny secondary and tertiary dendrites. Finally, neurons which discharge with a "single spike" to depolarizing pulses are round with four or five densely spiny dendrites, affording these neurons a mossy appearance. The results indicate that most of the amygdaloid neurons respond to carbachol with a depolarization. This effect was concomitant with either decrease or no change in the membrane input resistance and was not blocked by the addition of Ba2+, an M-current blocker, indicating that a conductance pathway other than K+ is involved in the response to carbachol.
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Abstract
The prefrontal cortex is involved in many processes, some of which are related to motor activity such eye movements and speech. Experimental data exist that suggest that prefrontal cortical activity occurs in relation to attention, short-term memory, affective discrimination, and complex forms of motor behaviour, i.e. anticipatory preparation, motor sequences, programming of speech, etc. We were interested in studying participation of this cortical region in locomotion. For this purpose, recordings were made of unitary activity in the prefrontal cortex of chronically prepared cats walking on an exercise belt that was moving at a speed of 0.1 m/s. From a total of 63 neurones in the prefrontal area from which recordings were made, 37 (59%) changed their activity during locomotion, 28 of which (76%) increased and 9 of which (24%) decreased their frequency of discharge; the remaining 26 units (41%) showed no locomotor-related change in activity. The results obtained show that 59% of prefrontal units are involved in the locomotor process and it is reasonable to assume that their activity contributes to the control of the movements.
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Peripherin fibers in the main olfactory bulb are different from olfactory fibers and from LHRH fibers: an immunocytochemical and DiI study. Brain Res 1996; 734:337-40. [PMID: 8896844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Fibers coming from the olfactory epithelium and entering the olfactory bulb expressed peripherin. These were not sensory olfactory fibers because: (1) they did not form glomeruli, (2) they did not express olfactory marker protein (OMP), (3) they entered deeply into the olfactory bulb, reaching its white matter. Cells and fibers in the olfactory bulb expressing luteinizing hormone-releasing hormone (LHRH) differed from those expressing peripherin because LHRH and peripherin did not coexist and the distributions of LHRH-positive and peripherin-positive fibers were found to be different.
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Presence of LHRH (luteinizing hormone-releasing hormone) fibers in the optic nerve, optic chiasm and optic tract of the adult rat. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1996; 91:292-9. [PMID: 8852381 DOI: 10.1016/0165-3806(95)00199-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In mammals LHRH (luteinizing hormone-releasing hormone) is synthesized and released by a set of neurons that have their embryonic origin in the olfactory placode. We have observed that, besides their classical location, LHRH fibers can also be seen in the optic nerve and optic chiasm. Some LHRH fibers could also be traced in the optic tract. The possible course of these projections, and their functional significance are discussed.
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Characterization of neuronal cell varieties migrating from the olfactory epithelium during prenatal development in the rat. Immunocytochemical study using antibodies against olfactory marker protein (OMP) and luteinizing hormone-releasing hormone (LH-RH). BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1993; 71:209-20. [PMID: 8491043 DOI: 10.1016/0165-3806(93)90173-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The development of neurons located outside the olfactory epithelium was studied by using antisera against olfactory marker protein (OMP) and luteinizing hormone-releasing hormone (LH-RH) in the rat. The study was restricted to the localization of these cells in the nasal cavity and in the region of the olfactory bulb during development. We describe groups of cells that stain positively for OMP located principally on the ventro-lateral aspect of the olfactory bulbs. A comparison is made with the LH-RH-immunoreactive system of cells which predominate on the medial aspect following the known trajectory of the nervus terminalis. OMP-immunoreactive cells appeared along the course of the olfactory fibers when they were first detected at embryonic day 16. These cells became restricted to a small group above the cribriform plate, ventral to the olfactory bulbs that seemed to disappear shortly after birth. It is concluded that these cells, which like the LH-RH cells have most probably migrated from the olfactory placode, represent a group of intervening neurons between the olfactory receptor cells and the olfactory bulb, serving as hints for olfactory axons to reach their targets during prenatal development.
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Transient pattern of exuberant projections of olfactory axons during development in the rat. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1992; 70:213-22. [PMID: 1477955 DOI: 10.1016/0165-3806(92)90200-g] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The purpose of our study was twofold: (1) to trace the development of the olfactory axons from early embryonic stages until the mature pattern of connectivity and (2) to determine whether a transient penetration of them exists beyond the olfactory glomeruli. Two techniques were employed: DiI applied in the olfactory epithelium after aldehyde fixation, and olfactory marker protein (OMP) immunostaining. At E13 and E14 olfactory axons were observed spreading over the telencephalic vesicle and entering deeply into the prospective olfactory bulb, extending near the ventricular zone. Growth cones were seen at the end of these axons. At E15, the bundles of olfactory axons form a network, in which axons, growth cones and cells were seen. Some of these axons entered the olfactory bulb. Using OMP immunostaining olfactory axons were observed along the external plexiform layer, the mitral cell layer and in the granular layer from E19 to P6. At P9 some OMP immunoreactive axons were observed in the external plexiform layer. No OMP immunostained axons could be observed outside the glomeruli at P10. Our conclusions are that a transient immature pattern of early invasion over the telencephalic vesicle and of the olfactory bulb by olfactory axons occurs in the olfactory system. By the second postnatal week the glomerular layer reaches its mature configuration, and no olfactory fibers are seen outside the glomerular layer.
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18
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Abstract
We have studied the development of olfactory nerves in the rat from their first contact with the telencephalic vesicle until the formation of glomerular structures in the olfactory bulb at early postnatal period. The study is based on serial semithin and ultrathin sections of material prepared for electron microscopy and antibodies to label radial glial cells, glial fibrillary acidic protein and Rat-401. Beginning on embryonic day 12, developing olfactory axons from the olfactory placode are accompanied by migratory cells, also derived from the olfactory placode, that reach the prospective olfactory bulb by embryonic day 13. The mass of migratory cells accumulate superficial to the telencephalic vesicle. The cells increase in number by mitotic divisions. The majority of these cells represent precursor elements that will later develop into the ensheathing cells of the olfactory nerves and olfactory nerve layer of the adult. Some migratory cells penetrate into the prospective olfactory bulb early during development. The first synaptic contacts of olfactory axons with dendritic processes in the olfactory bulb were observed at embryonic day 18. Glomerular formation is initiated by penetration of cells from the migratory mass into the prospective glomerular layer by embryonic day 20 to postnatal day 0. These cells form walls surrounding zones of high synaptic density forming protoglomeruli. Postnatally, the peripheral processes of radial glial cells branch profusely delimiting glomerular formations and transform into periglomerular astrocytes. Rat-401 stains radial glial cells from embryonic day 14. Immunoreactivity becomes restricted to the olfactory glomeruli during the first postnatal weeks and it virtually disappears by the end of the first postnatal month. We conclude that the early penetration of cells from the migratory mass into the prospective olfactory bulb, observed immediately after the first synaptic contacts were established, initiates the formation of olfactory glomeruli which becomes completed by the transformation of radial glial cells into periglomerular astrocytes.
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Development of the main efferent cells of the olfactory bulb and of the bulbar component of the anterior commissure. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1992; 65:75-83. [PMID: 1312914 DOI: 10.1016/0165-3806(92)90010-t] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The development of the efferent cells of the main olfactory bulb and the development of the bulbar part of the anterior commissure were studied in the rat from E16 to P7. DiI was used in fixed tissues as a neuronal tracer. From E16 onwards cells located in the olfactory bulb anlage were stained in a Golgi-like appearance. The morphological changes of these cells were: from E16 to P4, re-orientation from a tangential position to a radial position, elongation of the principal dendrite and spreading out of the secondary dendrites. From P4 onwards, there was a lack of migrating mitral cells in the inner part of the bulb. At E16 some fibers of the anterior commissure reached the midline, the number of fibers increased slowly until P0/P1. At P2 there was an explosive increase in the number of fibers crossing the midline and reaching the contralateral bulb. The development in two stages is hypothesized.
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Abstract
Carbocyanine DiI is described as a suitable fluorescent tracer to investigate the connectivity of cortical transplants. DiI was applied in 2 ways: in tissue previously fixed with aldehydes, and in vivo for labelling the donor tissue prior to transplantation. When applied in fixed tissue DiI travelled anterogradely, allowing the study of efferent connections from the transplant to the host. When DiI was applied in vivo, it travelled retrogradely showing the afferents to the transplant from the host.
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Transplant connectivity in the rat cerebral cortex. A carbocyanine study. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1990; 56:217-22. [PMID: 2261682 DOI: 10.1016/0165-3806(90)90085-d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Previous reports suggest that the specificity of connectivity between cortical areas and their related thalamic nuclei is established during development. We have used heterotopic E15, E17 and E19 transplants to determine at which embryonic age the cortex is mature enough to establish such specific connections. Carbocyanine DiI or Fluoro-Gold were used for labelling transplants. Efferent cortico-cortical, callosal and collicular connections were observed when DiI was applied in fixed tissue. Thalamic nuclei were labelled when DiI was used 'in vivo' or the transplants were labelled with Fluoro-Gold. The connections of the transplants were those corresponding to the area in which the transplants were placed. This suggests that up to E19 the embryonic cortex is too immature to define the specific thalamo-cortical connections.
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Development and differentiation of early generated cells of sublayer VIb in the somatosensory cortex of the rat: a correlated Golgi and autoradiographic study. J Comp Neurol 1989; 290:118-40. [PMID: 2480368 DOI: 10.1002/cne.902900108] [Citation(s) in RCA: 140] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Autoradiographic and Golgi techniques are used to study the origin, developmental characteristics, and adult morphology of the cells of sublayer VIb in the somatosensory cortex of the rat. In the adult rat, this sublayer forms a stratum of two to three rows of cells located immediately above the white matter. It is clearly separated from the remaining cortical layers by a light plexus of fibers. The cortical plate begins to appear in the lateral wall of the brain hemisphere at embryonic day 15 (E15). By using tritiated thymidine autoradiography, we can see that cells generated between E12 and E14 become located in layers I, V, and VI in the adult. After injections on E12, heavily labeled cells were found almost exclusively in layer I and in sublayer VIb, indicating that these are the earliest generated cells in the neocortex of the rat. No labeled cells were found in sublayer VIb after injection on E15. We describe the morphology of cells of layer VI from E15 to the adult using the Golgi technique. Our observations show the existence of different types of cells, among which we found horizontal bipolar cells very early during development. They transform into horizontal and inverted pyramidal cells, which are the predominant morphological types found in the adult. Horizontal cells lie at the lower part of sublayer VIb. Inverted pyramidal cells have descending apical dendrites penetrating the white matter. Their axons form ascending loops turning into projection fibers. A correlation with previous studies and some functional implications indicating the unique role of sublayer VIb in the rat during development and in the adult are discussed.
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