Early Corticostriatal Projections and Development of Striatal Patch/Matrix Organization

AbstractAnimals exhibit innate defense behaviors in response to approaching threats cued by the dynamics of sensory inputs of various modalities. The underlying neural circuits have been mostly studied in the visual system, but remain unclear for other modalities. Here, by utilizing sounds with increasing (vs. decreasing) loudness to mimic looming (vs. receding) objects, we find that looming sounds elicit stereotypical sequential defensive reactions: freezing followed by flight. Both behaviors require the activity of auditory cortex, in particular the sustained type of responses, but are differentially mediated by corticostriatal projections primarily innervating D2 neurons in the tail of the striatum and corticocollicular projections to the superior colliculus, respectively. The behavioral transition from freezing to flight can be attributed to the differential temporal dynamics of the striatal and collicular neurons in their responses to looming sound stimuli. Our results reveal an essential role of the striatum in the innate defense control.

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Transcription Landscape of the Early Developmental Biology in Pigs

Animals ◽

10.3390/ani11051443 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1443

Author(s):

Susana A. Teixeira ◽

Daniele B. D. Marques ◽

Thaís C. Costa ◽

Haniel C. Oliveira ◽

Karine A. Costa ◽

...

Keyword(s):

Transcriptional Control ◽

Muscle Development ◽

Neuronal Development ◽

Striated Muscle ◽

Prenatal Development ◽

Sequencing Analysis ◽

Neuronal System ◽

Matrix Organization ◽

Early Developmental ◽

Transcriptional Landscape

Since pre- and postnatal development are programmed during early prenatal life, studies addressing the complete transcriptional landscape during organogenesis are needed. Therefore, we aimed to disentangle differentially expressed (DE) genes between fetuses (at 35 days old) and embryos (at 25 days old) through RNA-sequencing analysis using the pig as model. In total, 1705 genes were DE, including the top DE IBSP, COL6A6, HBE1, HBZ, HBB, and NEUROD6 genes, which are associated with developmental transition from embryos to fetuses, such as ossification, skeletal muscle development, extracellular matrix organization, cardiovascular system, erythrocyte differentiation, and neuronal system. In pathway analysis, embryonic development highlighted those mainly related to morphogenic signaling and cell interactions, which are crucial for transcriptional control during the establishment of the main organs in early prenatal development, while pathways related to myogenesis, neuronal development, and cardiac and striated muscle contraction were enriched for fetal development, according to the greater complexity of organs and body structures at this developmental stage. Our findings provide an exploratory and informative transcriptional landscape of pig organogenesis, which might contribute to further studies addressing specific developmental events in pigs and in other mammals.

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Effect of Uniaxial Tensile Cyclic Loading Regimes on Matrix Organization and Tenogenic Differentiation of Adipose-Derived Stem Cells Encapsulated within 3D Collagen Scaffolds

Stem Cells International ◽

10.1155/2017/6072406 ◽

2017 ◽

Vol 2017 ◽

pp. 1-16 ◽

Cited By ~ 5

Author(s):

Gayathri Subramanian ◽

Alexander Stasuk ◽

Mostafa Elsaadany ◽

Eda Yildirim-Ayan

Keyword(s):

Gene Expression ◽

Stem Cells ◽

Expression Profiles ◽

Three Dimensional ◽

Uniaxial Tensile ◽

Adipose Derived Stem Cells ◽

Collagen Scaffolds ◽

Differentiation Potential ◽

Tenogenic Differentiation ◽

Matrix Organization

Adipose-derived mesenchymal stem cells have become a popular cell choice for tendon repair strategies due to their relative abundance, ease of isolation, and ability to differentiate into tenocytes. In this study, we investigated the solo effect of different uniaxial tensile strains and loading frequencies on the matrix directionality and tenogenic differentiation of adipose-derived stem cells encapsulated within three-dimensional collagen scaffolds. Samples loaded at 0%, 2%, 4%, and 6% strains and 0.1 Hz and 1 Hz frequencies for 2 hours/day over a 7-day period using a custom-built uniaxial tensile strain bioreactor were characterized in terms of matrix organization, cell viability, and musculoskeletal gene expression profiles. The results displayed that the collagen fibers of the loaded samples exhibited increased matrix directionality with an increase in strain values. Gene expression analyses demonstrated that ASC-encapsulated collagen scaffolds loaded at 2% strain and 0.1 Hz frequency showed significant increases in extracellular matrix genes and tenogenic differentiation markers. Importantly, no cross-differentiation potential to osteogenic, chondrogenic, and myogenic lineages was observed at 2% strain and 0.1 Hz frequency loading condition. Thus, 2% strain and 0.1 Hz frequency were identified as the appropriate mechanical loading regime to induce tenogenic differentiation of adipose-derived stem cells cultured in a three-dimensional environment.

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