Postnatal maturation of glutamatergic inputs onto rat jaw-closing and jaw-opening motoneurons

Author(s):  
Shiro Nakamura ◽  
Risa Kajiwara ◽  
Tsuyoshi Noguchi ◽  
Kiyomi Nakayama ◽  
Ayako Mochizuki ◽  
...  
1990 ◽  
Vol 44 (2) ◽  
pp. 440-453 ◽  
Author(s):  
Kazuo Saeki ◽  
Masahiro Ohta ◽  
Satoru Ishizuka ◽  
Makoto Iwasaki

Endocrinology ◽  
2013 ◽  
Vol 154 (3) ◽  
pp. 1321-1336 ◽  
Author(s):  
Francisco Gaytan ◽  
Susana Sangiao-Alvarellos ◽  
María Manfredi-Lozano ◽  
David García-Galiano ◽  
Francisco Ruiz-Pino ◽  
...  

Abstract Lin28 (also termed Lin28a) and Lin28b are related RNA-binding proteins, involved in the control of microRNA synthesis, especially of the let-7 family, with putative functions in early (embryo) development. However, their roles during postnatal maturation remain ill defined. Despite the general assumption that Lin28 and Lin28b share similar targets and functions, conclusive demonstration of such redundancy is still missing. In addition, recent observations suggest a role of Lin28 proteins in mammalian reproduction, which is yet to be defined. We document herein the patterns of RNA expression and protein distribution of Lin28 and Lin28b in mouse testis during postnatal development and in a model of hypogonadotropic hypogonadism as a result of inactivation of the kisspeptin receptor, Gpr54. Lin28 and Lin28b mRNAs were expressed in mouse testis across postnatal maturation, but their levels disparately varied between neonatal and pubertal periods, with peak Lin28 levels in infantile testes and sustained elevation of Lin28b mRNA in young adult male gonads, where relative levels of let-7a and let-7b miRNAs were significantly suppressed. In addition, Lin28 peptides displayed totally different patterns of cellular distribution in mouse testis: Lin28 was located in undifferentiated and type-A1 spermatogonia, whereas Lin28b was confined to spermatids and interstitial Leydig cells. These profiles were perturbed in Gpr54 null mouse testis, which showed preserved but irregular Lin28 signal and absence of Lin28b peptide, which was rescued by administration of gonadotropins, mainly hCG (as super-agonist of LH). In addition, increased relative levels of Lin28, but not Lin28b, mRNA and of let-7a/let-7b miRNAs were observed in Gpr54 KO mouse testes. Altogether, our data are the first to document the divergent patterns of cellular distribution and mRNA expression of Lin28 and Lin28b in the mouse testis along postnatal maturation and their alteration in a model of congenital hypogonadotropic hypogonadism. Our findings suggest distinct functional roles of these two related, but not overlapping, miRNA-binding proteins in the male gonad.


2021 ◽  
pp. 190-199
Author(s):  
Samra Hamzic ◽  
Patrick Schramm ◽  
Hassan Khilan ◽  
Tibo Gerriets ◽  
Martin Juenemann

Medial medullary infarction (MMI) is a vascular occlusion in the medulla oblongata leading to certain constellations of neurological symptoms and seriously affecting the patient. Effective evidence-based treatment of severe dysphagia as sole symptom of MMI has not yet been reported. This case study aims to report successful effects of evidence-based therapy based on findings of dysphagia symptoms and pathophysiology of swallowing by flexible endoscopic evaluation of swallowing (FEES) in severe isolated dysphagia after MMI. FEES was performed to evaluate swallowing pathophysiology and dysphagia symptoms in a 57-year-old male with severe dysphagia after MMI. On the basis of FEES findings, simple and high-frequent evidence-based exercises for improvement of swallowing were implemented: thermal stimulation of faucial arches, Jaw Opening Exercise, and Jaw Opening Against Resistance. After 7 weeks of high-frequent evidence-based therapy and regular FEES evaluation the patient was set on full oral diet with no evidence of aspiration risk. In a first case report of isolated dysphagia in MMI our case illustrates that high-frequent evidence-based dysphagia therapy in combination with FEES as the method to evaluate and monitor swallowing pathophysiology can lead to successful and quick rehabilitation of severely affected dysphagic patients.


Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1686
Author(s):  
Adelaida M. Celaya ◽  
Lourdes Rodríguez-de la Rosa ◽  
Jose M. Bermúdez-Muñoz ◽  
José M. Zubeldia ◽  
Carlos Romá-Mateo ◽  
...  

Insulin-like growth factor 1 (IGF-1) deficiency is an ultrarare syndromic human sensorineural deafness. Accordingly, IGF-1 is essential for the postnatal maturation of the cochlea and the correct wiring of hearing in mice. Less severe decreases in human IGF-1 levels have been associated with other hearing loss rare genetic syndromes, as well as with age-related hearing loss (ARHL). However, the underlying mechanisms linking IGF-1 haploinsufficiency with auditory pathology and ARHL have not been studied. Igf1-heterozygous mice express less Igf1 transcription and have 40% lower IGF-1 serum levels than wild-type mice. Along with ageing, IGF-1 levels decreased concomitantly with the increased expression of inflammatory cytokines, Tgfb1 and Il1b, but there was no associated hearing loss. However, noise exposure of these mice caused increased injury to sensory hair cells and irreversible hearing loss. Concomitantly, there was a significant alteration in the expression ratio of pro- and anti-inflammatory cytokines in Igf1+/− mice. Unbalanced inflammation led to the activation of the stress kinase JNK and the failure to activate AKT. Our data show that IGF-1 haploinsufficiency causes a chronic subclinical proinflammatory age-associated state and, consequently, greater susceptibility to stressors. This work provides the molecular bases to further understand hearing disorders linked to IGF-1 deficiency.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alyssa Maxwell ◽  
Iris Adam ◽  
Pernille S. Larsen ◽  
Peter G. Sørensen ◽  
Coen P. H. Elemans

AbstractVocal behavior can be dramatically changed by both neural circuit development and postnatal maturation of the body. During song learning in songbirds, both the song system and syringeal muscles are functionally changing, but it is unknown if maturation of sound generators within the syrinx contributes to vocal development. Here we densely sample the respiratory pressure control space of the zebra finch syrinx in vitro. We show that the syrinx produces sound very efficiently and that key acoustic parameters, minimal fundamental frequency, entropy and source level, do not change over development in both sexes. Thus, our data suggest that the observed acoustic changes in vocal development must be attributed to changes in the motor control pathway, from song system circuitry to muscle force, and not by material property changes in the avian analog of the vocal folds. We propose that in songbirds, muscle use and training driven by the sexually dimorphic song system are the crucial drivers that lead to sexual dimorphism of the syringeal skeleton and musculature. The size and properties of the instrument are thus not changing, while its player is.


2021 ◽  
Vol 22 (7) ◽  
pp. 3616
Author(s):  
Ewelina Jozefczuk ◽  
Piotr Szczepaniak ◽  
Tomasz Jan Guzik ◽  
Mateusz Siedlinski

Sphingosine kinase-1 (Sphk1) and its product, sphingosine-1-phosphate (S1P) are important regulators of cardiac growth and function. Numerous studies have reported that Sphk1/S1P signaling is essential for embryonic cardiac development and promotes pathological cardiac hypertrophy in adulthood. However, no studies have addressed the role of Sphk1 in postnatal cardiomyocyte (CM) development so far. The present study aimed to assess the molecular mechanism(s) by which Sphk1 silencing might influence CMs development and hypertrophy in vitro. Neonatal mouse CMs were transfected with siRNA against Sphk1 or negative control, and subsequently treated with 1 µM angiotensin II (AngII) or a control buffer for 24 h. The results of RNASeq analysis revealed that diminished expression of Sphk1 significantly accelerated neonatal CM maturation by inhibiting cell proliferation and inducing developmental pathways in the stress (AngII-induced) conditions. Importantly, similar effects were observed in the control conditions. Enhanced maturation of Sphk1-lacking CMs was further confirmed by the upregulation of the physiological hypertrophy-related signaling pathway involving Akt and downstream glycogen synthase kinase 3 beta (Gsk3β) downregulation. In summary, we demonstrated that the Sphk1 silencing in neonatal mouse CMs facilitated their postnatal maturation in both physiological and stress conditions.


2011 ◽  
Vol 115 (2) ◽  
pp. 273-281 ◽  
Author(s):  
Masato Kobayashi ◽  
Takao Ayuse ◽  
Yuko Hoshino ◽  
Shinji Kurata ◽  
Shunji Moromugi ◽  
...  

Background Head elevation can restore airway patency during anesthesia, although its effect may be offset by concomitant bite opening or accidental neck flexion. The aim of this study is to examine the effect of head elevation on the passive upper airway collapsibility during propofol anesthesia. Method Twenty male subjects were studied, randomized to one of two experimental groups: fixed-jaw or free-jaw. Propofol infusion was used for induction and to maintain blood at a constant target concentration between 1.5 and 2.0 μg/ml. Nasal mask pressure (PN) was intermittently reduced to evaluate the upper airway collapsibility (passive PCRIT) and upstream resistance (RUS) at each level of head elevation (0, 3, 6, and 9 cm). The authors measured the Frankfort plane (head flexion) and the mandible plane (jaw opening) angles at each level of head elevation. Analysis of variance was used to determine the effect of head elevation on PCRIT, head flexion, and jaw opening within each group. Results In both groups the Frankfort plane and mandible plane angles increased with head elevation (P < 0.05), although the mandible plane angle was smaller in the free-jaw group (i.e., increased jaw opening). In the fixed-jaw group, head elevation decreased upper airway collapsibility (PCRIT ~ -7 cm H₂O at greater than 6 cm elevation) compared with the baseline position (PCRIT ~ -3 cm H₂O at 0 cm elevation; P < 0.05). Conclusion : Elevating the head position by 6 cm while ensuring mouth closure (centric occlusion) produces substantial decreases in upper airway collapsibility and maintains upper airway patency during anesthesia.


1989 ◽  
Vol 257 (4) ◽  
pp. R765-R770 ◽  
Author(s):  
K. T. Nakamura ◽  
J. M. Klinkefus ◽  
F. G. Smith ◽  
T. Sato ◽  
J. E. Robillard

The role of renal nerves and norepinephrine release on renin secretion during fetal and postnatal maturation has not been studied. Experiments were performed to determine the effect of veratridine, a substance known to promote norepinephrine release from nerve terminals, on active and inactive renin secretion from renal cortical slices of fetal (134-138 days gestation; term is 145 days), newborn (4-9 days of age), and adult nonpregnant sheep. Veratridine (10-300 microM) significantly increased active renin secretion and produced a small but nonsignificant rise in inactive renin secretion in all three groups of animals (P less than 0.05). The percent rise in active renin secretion during veratridine stimulation was similar among all groups. Veratridine-stimulated (300 microM) active renin secretion was antagonized by tetrodotoxin (0.5 and 5.0 microM) and DL-propranolol (1 microM) in fetal renal cortical slices. However, neither tetrodotoxin nor propranolol completely inhibited the stimulatory effect of veratridine on active renin secretion. These results suggest that 1) norepinephrine released from nerve terminals may regulate active renin secretion early during development; 2) the effect of veratridine on active renin secretion was similar in fetal, newborn, and adult sheep; 3) veratridine had no significant effect on inactive renin secretion; and 4) active renin secretion due to depolarization of nerve terminals in fetal sheep is dependent on activation of beta-adrenoceptors as it is in adults.


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