scholarly journals Role of Nrp1 in controlling cortical interhemispheric circuits

2021 ◽  
Author(s):  
Fernando Martín Fernández ◽  
Carlos Garcia Briz ◽  
Marta Nieto

Callosal projections establish topographically organized maps between cortical areas. Neuropilin-1 (Nrp1) cortical gradient induces an early segregation of developing callosal axons. We investigated later roles of Nrp1 on the development of callosal projections from layer (L) 2/3 of the primary (S1) and secondary (S2) somatosensory (SS) areas, which express higher and lower levels of Nrp1, respectively. We used in utero electroporation to knock down or overexpress Nrp1 combined with retrograde tracers, to map connections at postnatal day 16 and 30. High levels of Nrp1 blocked contralateral S2 innervation while promoted the late postnatal growth of homotopic S1L2/3 and heterotopic S2L2/3 branches into S1. Conversely, knocking down Nrp1 increased the growth of heterotopic S1L2/3 projections into S2, and the overall refinement of S2L2/3 branches, thereby diminishing the number of P30 S2L2/3 callosally projecting neurons. Thus, the Nrp1 gradient determines homotopic SSL2/3 callosal connectivity by regulating late postnatal branching and refinement in a topographic manner.

2018 ◽  
Vol 29 (10) ◽  
pp. 4303-4311
Author(s):  
Kengo Saito ◽  
Keishi Mizuguchi ◽  
Toshihide Horiike ◽  
Tung Anh Dinh Duong ◽  
Yohei Shinmyo ◽  
...  

Abstract Changes in the cerebral cortex of mammals during evolution have been of great interest. Ferrets, monkeys, and humans have more developed cerebral cortices compared with mice. Although the features of progenitors in the developing cortices of these animals have been intensively investigated, those of the fiber layers are still largely elusive. By taking the advantage of our in utero electroporation technique for ferrets, here we systematically investigated the cellular origins and projection patterns of axonal fibers in the developing ferret cortex. We found that ferrets have 2 fiber layers in the developing cerebral cortex, as is the case in monkeys and humans. Axonal fibers in the inner fiber layer projected contralaterally and subcortically, whereas those in the outer fiber layer sent axons to neighboring cortical areas. Furthermore, we performed similar experiments using mice and found unexpected similarities between ferrets and mice. Our results shed light on the cellular origins, the projection patterns, the developmental processes, and the evolution of fiber layers in mammalian brains.


Neuroscience ◽  
2020 ◽  
Vol 441 ◽  
pp. 65-76
Author(s):  
Ramona Frida Moroni ◽  
Maria Cristina Regondi ◽  
Marco de Curtis ◽  
Carolina Frassoni ◽  
Laura Librizzi

2019 ◽  
Author(s):  
Russell J. Taylor ◽  
Justin Carrington ◽  
Kendra L. Taylor ◽  
Karl E. Richters ◽  
Leah R. Gerlach ◽  
...  

In Utero Electroporation is a powerful tool for testing the role of genes in neuronal migration, but this technique suffers from high degrees of variability due to multiple factors. Therefore, we developed Double UP, a novel approach that combines LoxP-flanked reporters and limiting Cre dosages to generate internal controls. This technique allows for more rigorous quantification of migration, while decreasing the number of animals, reagents and time to complete experiments.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael Lohse ◽  
Johannes C. Dahmen ◽  
Victoria M. Bajo ◽  
Andrew J. King

AbstractIntegration of information across the senses is critical for perception and is a common property of neurons in the cerebral cortex, where it is thought to arise primarily from corticocortical connections. Much less is known about the role of subcortical circuits in shaping the multisensory properties of cortical neurons. We show that stimulation of the whiskers causes widespread suppression of sound-evoked activity in mouse primary auditory cortex (A1). This suppression depends on the primary somatosensory cortex (S1), and is implemented through a descending circuit that links S1, via the auditory midbrain, with thalamic neurons that project to A1. Furthermore, a direct pathway from S1 has a facilitatory effect on auditory responses in higher-order thalamic nuclei that project to other brain areas. Crossmodal corticofugal projections to the auditory midbrain and thalamus therefore play a pivotal role in integrating multisensory signals and in enabling communication between different sensory cortical areas.


Author(s):  
Rachel L. Leon ◽  
Imran N. Mir ◽  
Christina L. Herrera ◽  
Kavita Sharma ◽  
Catherine Y. Spong ◽  
...  

Abstract Children with congenital heart disease (CHD) are living longer due to effective medical and surgical management. However, the majority have neurodevelopmental delays or disorders. The role of the placenta in fetal brain development is unclear and is the focus of an emerging field known as neuroplacentology. In this review, we summarize neurodevelopmental outcomes in CHD and their brain imaging correlates both in utero and postnatally. We review differences in the structure and function of the placenta in pregnancies complicated by fetal CHD and introduce the concept of a placental inefficiency phenotype that occurs in severe forms of fetal CHD, characterized by a myriad of pathologies. We propose that in CHD placental dysfunction contributes to decreased fetal cerebral oxygen delivery resulting in poor brain growth, brain abnormalities, and impaired neurodevelopment. We conclude the review with key areas for future research in neuroplacentology in the fetal CHD population, including (1) differences in structure and function of the CHD placenta, (2) modifiable and nonmodifiable factors that impact the hemodynamic balance between placental and cerebral circulations, (3) interventions to improve placental function and protect brain development in utero, and (4) the role of genetic and epigenetic influences on the placenta–heart–brain connection. Impact Neuroplacentology seeks to understand placental connections to fetal brain development. In fetuses with CHD, brain growth abnormalities begin in utero. Placental microstructure as well as perfusion and function are abnormal in fetal CHD.


2021 ◽  
Vol 22 (4) ◽  
pp. 1858
Author(s):  
Waheed Shabbir ◽  
Nermina Topcagic ◽  
Mohammed Aufy ◽  
Murat Oz

Tumor necrosis factor (TNF) is known to activate the epithelial Na+ channel (ENaC) in A549 cells. A549 cells are widely used model for ENaC research. The role of δ-ENaC subunit in TNF-induced activation has not been studied. In this study we hypothesized that δ-ENaC plays a major role in TNF-induced activation of ENaC channel in A549 cells which are widely used model for ENaC research. We used CRISPR/Cas 9 approach to knock down (KD) the δ-ENaC in A549 cells. Western blot and immunofluorescence assays were performed to analyze efficacy of δ-ENaC protein KD. Whole-cell patch clamp technique was used to analyze the TNF-induced activation of ENaC. Overexpression of wild type δ-ENaC in the δ-ENaC KD of A549 cells restored the TNF-induced activation of whole-cell Na+ current. Neither N-linked glycosylation sites nor carboxyl terminus domain of δ-ENaC was necessary for the TNF-induced activation of whole-cell Na+ current in δ-ENaC KD of A549 cells. Our data demonstrated that in A549 cells the δ-ENaC plays a major role in TNF-induced activation of ENaC.


1965 ◽  
Vol 43 (3) ◽  
pp. 431-436 ◽  
Author(s):  
M. Samel ◽  
A. Caputa

In newborn rats the mother provokes the emptying of the urinary bladder by stimulating the perineum with her tongue. The possibility that mothers may thereby ingest the urine of their young has been studied by means of 131I on nine litters of rats aged 10 to 29 days. The results indicate that a considerable quantity of 131I administered intraperitoneally to 10- and 18-day-old rats, which were then reunited with their mothers for 4 hours, reappears in the organism of uninjected nurslings after passing through the organism of the mother. The amount of 131I transferred from injected rats into the bodies of isolated uninjected rats of the same litter decreased during the period of weaning. The observed recirculation of 131I between immature rats and their mothers in both directions may represent a saving mechanism which might include several other substances and would compensate for their loss via the milk, and suggests a new aspect of maternal–neonatal interrelationship which appears as a continuation of the state existing in utero.


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