scholarly journals MEF2C and HDAC5 regulate Egr1 and Arc genes to increase dendritic spine density and complexity in early enriched environment

2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Shu Juan Puang ◽  
Bavani Elanggovan ◽  
Tendy Ching ◽  
Judy C.G. Sng

Abstract We investigated the effects of environmental enrichment during critical period of early postnatal life and how it interplays with the epigenome to affect experience-dependent visual cortical plasticity. Mice raised in an EE from birth to during CP have increased spine density and dendritic complexity in the visual cortex. EE upregulates synaptic plasticity genes, Arc and Egr1, and a transcription factor MEF2C. We also observed an increase in MEF2C binding to the promoters of Arc and Egr1. In addition, pups raised in EE show a reduction in HDAC5 and its binding to promoters of Mef2c, Arc and Egr1 genes. With an overexpression of Mef2c, neurite outgrowth increased in complexity. Our results suggest a possible underlying molecular mechanism of EE, acting through MEF2C and HDAC5, which drive Arc and Egr1. This could lead to the observed increased dendritic spine density and complexity induced by early EE.

2011 ◽  
Vol 115 (2) ◽  
pp. 282-293 ◽  
Author(s):  
Adrian Briner ◽  
Irina Nikonenko ◽  
Mathias De Roo ◽  
Alexandre Dayer ◽  
Dominique Muller ◽  
...  

Background Recent observations demonstrate that anesthetics rapidly impair synaptogenesis during neuronal circuitry development. Whether these effects are lasting and depend on the developmental stage at which these drugs are administered remains, however, to be explored. Methods Wistar rats received propofol anesthesia at defined developmental stages during early postnatal life. The acute and long-term effects of these treatments on neuronal cytoarchitecture were evaluated by Neurolucida and confocal microscopy analysis after iontophoretic injections of Lucifer Yellow into layer 5 pyramidal neurons in the medial prefrontal cortex. Quantitative electron microscopy was applied to investigate synapse density. Results Layer 5 pyramidal neurons of the medial prefrontal cortex displayed intense dendritic growth and spinogenesis during the first postnatal month. Exposure of rat pups to propofol at postnatal days 5 and 10 significantly decreased dendritic spine density, whereas this drug induced a significant increase in spine density when administered at postnatal days 15, 20, or 30. Quantitative electron microscopy revealed that the propofol-induced increase in spine density was accompanied by a significant increase in the number of synapses. Importantly, the propofol-induced modifications in dendritic spine densities persisted up to postnatal day 90. Conclusion These new results demonstrate that propofol anesthesia can rapidly induce significant changes in dendritic spine density and that these effects are developmental stage-dependent, persist into adulthood, and are accompanied by alterations in synapse number. These data suggest that anesthesia in the early postnatal period might permanently impair circuit assembly in the developing brain.


2013 ◽  
Vol 241 ◽  
pp. 25-33 ◽  
Author(s):  
Joseane Jiménez Rojas ◽  
Bruna Ferrary Deniz ◽  
Patrícia Maidana Miguel ◽  
Ramiro Diaz ◽  
Érica do Espírito-Santo Hermel ◽  
...  

2019 ◽  
Author(s):  
Brendan B. McAllister ◽  
Sarah E. Thackray ◽  
Brenda Karina Garciá de la Orta ◽  
Elise Gosse ◽  
Purnoor Tak ◽  
...  

ABSTRACTIn the central nervous system, certain neurons store zinc within the synaptic vesicles of their axon terminals. This vesicular zinc can then be released in an activity-dependent fashion as an intercellular signal. The functions of vesicular zinc are not entirely understood, but evidence suggests that it is important for some forms of experience-dependent plasticity in the brain. The ability of neurons to store and release vesicular zinc is dependent on expression of the vesicular zinc transporter, ZnT3. Here, we examined the neuronal morphology of mice that lack ZnT3. Brains were collected from mice housed under standard laboratory conditions and from mice housed in enriched environments – large, multilevel enclosures with running wheels, numerous objects and tunnels, and a greater number of cage mates. Golgi-Cox staining was used to visualize neurons for analysis of dendritic length and dendritic spine density. Neurons were analyzed from the barrel cortex, striatum, basolateral amygdala, and hippocampus (CA1). ZnT3 knockout mice, relative to wild type mice, exhibited increased basal dendritic length in the layer 2/3 pyramidal neurons of barrel cortex, independently of housing condition. Environmental enrichment decreased apical dendritic length in these same neurons and increased dendritic spine density on striatal medium spiny neurons. Elimination of ZnT3 did not modulate any of the effects of enrichment. Our results provide no evidence that vesicular zinc is required for the experience-dependent changes that occur in response to environmental enrichment. They are consistent, however, with recent reports suggesting increased cortical volume in ZnT3 knockout mice.


2021 ◽  
pp. 105253
Author(s):  
Katherine M. Bland ◽  
Adam Aharon ◽  
Eden L. Widener ◽  
M. Irene Song ◽  
Zachary O. Casey ◽  
...  

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