scholarly journals Cirbp-PSD95 axis protects against hypobaric hypoxia-induced aberrant morphology of hippocampal dendritic spines and cognitive deficits

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yang Zhou ◽  
Huanyu Lu ◽  
Ying Liu ◽  
Zaihua Zhao ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Cognitive Deficits ◽  
Dendritic Spine ◽  
Hippocampal Neurons ◽  
Hypobaric Hypoxia ◽  
Rna Binding ◽  
Spine Injury ◽  
Spine Density ◽  
Hypoxia Exposure ◽  
Ca1 Region ◽  
Hippocampal Ca1 Region

AbstractHypobaric hypoxia (HH) is a typical characteristic of high altitude environment and causes a spectrum of pathophysiological effects, including headaches, gliovascular dysfunction and cognitive retardation. Here, we sought to understand the mechanisms underlying cognitive deficits under HH exposure. Our results showed that hypobaric hypoxia exposure impaired cognitive function and suppressed dendritic spine density accompanied with increased neck length in both basal and apical hippocampal CA1 region neurons in mice. The expression of PSD95, a vital synaptic scaffolding molecule, is down-regulated by hypobaric hypoxia exposure and post-transcriptionally regulated by cold-inducible RNA-binding protein (Cirbp) through 3′-UTR region binding. PSD95 expressing alleviates hypoxia-induced dendritic spine morphology changes of hippocampal neurons and memory deterioration. Moreover, overexpressed Cirbp in hippocampus rescues HH-induced abnormal expression of PSD95 and attenuates hypoxia-induced dendritic spine injury and cognitive retardation. Thus, our findings reveal a novel mechanism that Cirbp-PSD-95 axis appears to play an essential role in HH-induced cognitive dysfunction in mice.

scholarly journals Cirbp-PSD95 Axis Protects Against Hypobaric Hypoxia-Induced Aberrant Morphology of Hippocampal Dendritic Spines and Cognitive Deficits

2020 ◽  
Author(s):  
Yang Zhou ◽  
Huanyu Lu ◽  
Ying Liu ◽  
Zaihua Zhao ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Cognitive Deficits ◽  
Dendritic Spine ◽  
Cognitive Abilities ◽  
Hypobaric Hypoxia ◽  
Rna Binding ◽  
Cognitive Outcomes ◽  
Spine Injury ◽  
Spine Density ◽  
Hypoxia Exposure ◽  
Ca1 Region

Abstract Hypobaric hypoxia (HH) is a typical characteristic of high altitude environment and causes a spectrum of pathophysiological effects, including headaches, gliovascular dysfunction and cognitive slowing. Here, we sought to understand the mechanisms underlying cognitive deficits under HH exposure. Our results showed that HH exposure impaired cognitive function and suppressed dendritic spine density accompanied with increased neck length in both basal and apical hippocampal CA1 region neurons. The expression of PSD95, a critical synaptic scaffolding molecule, is down-regulated by hypoxia exposure and post-transcriptionally controlled by cold-inducible RNA-binding protein (Cirbp) through 3’-UTR region binding. PSD95 expressing alleviates hypoxia-induced neuron dendritic spine plasticity abnormality and memory impairment. Moreover, overexpressed Cirbp in hippocampus rescues hypoxia-induced loss of PSD95 and attenuates hypoxia-induced dendritic spine injury and cognitive outcomes. Thus, our findings reveal a novel mechanism where Cirbp-PSD-95 axis appears to play a key role in hypoxia-induced cognitive abilities impairment in brain.

scholarly journals The Polyadenosine RNA Binding Protein ZC3H14 is Required in Mice for Proper Dendritic Spine Density

2020 ◽  
Author(s):  
Stephanie K. Jones ◽  
Jennifer Rha ◽  
Sarah Kim ◽  
Kevin J. Morris ◽  
Omotola F. Omotade ◽  
...  
Keyword(s):  
Dendritic Spine ◽  
Hippocampal Neurons ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Spine Density ◽  
Dendritic Spine Density

AbstractZC3H14 (Zinc finger CysCysCysHis domain-containing protein 14), an evolutionarily conserved member of a class of tandem zinc finger (CCCH) polyadenosine (polyA) RNA binding proteins, is associated with a form of heritable, nonsyndromic autosomal recessive intellectual disability. Previous studies of a loss of function mouse model, Zc3h14Δex13/Δex13, provide evidence that ZC3H14 is essential for proper brain function, specifically for working memory. To expand on these findings, we analyzed the dendrites and dendritic spines of hippocampal neurons from Zc3h14Δex13/Δex13 mice, both in situ and in vitro. These studies reveal that loss of ZC3H14 is associated with a decrease in total spine density in hippocampal neurons in vitro as well as in the dentate gyrus of 5-month old mice analyzed in situ. This reduction in spine density in vitro results from a decrease in the number of mushroom-shaped spines, which is rescued by exogenous expression of ZC3H14. We next performed biochemical analyses of synaptosomes prepared from whole wild-type and Zc3h14Δex13/Δex13 mouse brains to determine if there are changes in steady state levels of postsynaptic proteins upon loss of ZC3H14. We found that ZC3H14 is present within synaptosomes and that a crucial postsynaptic protein, CaMKIIα, is significantly increased in these synaptosomal fractions upon loss of ZC3H14. Together, these results demonstrate that ZC3H14 is necessary for proper dendritic spine density in cultured hippocampal neurons and in some regions of the mouse brain. These findings provide insight into how a ubiquitously expressed RNA binding protein leads to neuronal-specific defects that result in brain dysfunction.

scholarly journals P3-380: Dendritic spine density deficits in the hippocampal CA1 region of young Tg2576 mice are ameliorated with the PDE9A inhibitor PF-04447943

2010 ◽  
Vol 6 ◽  
pp. S563-S564 ◽  
Author(s):  
Robin J. Kleiman ◽  
Thomas A. Lanz ◽  
James E. Finley ◽  
Susan E. Bove ◽  
Mark J. Majchrzak ◽  
...  
Keyword(s):  
Dendritic Spine ◽  
Spine Density ◽  
Ca1 Region ◽  
Hippocampal Ca1 Region ◽  
Dendritic Spine Density ◽  
Hippocampal Ca1 ◽  
Tg2576 Mice

scholarly journals Caspase-6-cleaved Tau fails to induce Tau hyperphosphorylation and aggregation, neurodegeneration, glial inflammation, and cognitive deficits

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Anastasia Noël ◽  
Bénédicte Foveau ◽  
Andréa C. LeBlanc
Keyword(s):  
Cognitive Deficits ◽  
Tau Hyperphosphorylation ◽  
Spine Density ◽  
Tau Pathology ◽  
Ca1 Region ◽  
Hippocampal Ca1 Region ◽  
Hippocampal Ca1 ◽  
Age Dependent ◽  
Cornu Ammonis ◽  
Caspase 6

AbstractActive Caspase-6 (Casp6) and Tau cleaved by Casp6 at amino acids 402 (Tau∆D402) and 421 (Tau∆D421) are present in early Alzheimer disease intraneuronal neurofibrillary tangles, which are made primarily of filamentous Tau aggregates. To assess whether Casp6 cleavage of Tau contributes to Tau pathology and Casp6-mediated age-dependent cognitive impairment, we generated transgenic knock-in mouse models that conditionally express full-length human Tau (hTau) 0N4R only (CTO) or together with human Casp6 (hCasp6) (CTC). Region-specific hippocampal and cortical hCasp6 and hTau expression were confirmed with western blot and immunohistochemistry in 2–25-month-old brains. Casp6 activity was confirmed with Tau∆D421 and Tubulin cleaved by Casp6 immunopositivity in 3–25-month-old CTC, but not in CTO, brains. Immunoprecipitated Tau∆D402 was detected in both CTC and CTO brains, but was more abundant in CTC brains. Intraneuronal hippocampal Tau hyperphosphorylation at S202/T205, S422, and T231, and Tau conformational change were absent in both CTC and CTO brains. A slight accumulation of Tau phosphorylated at S396/404 and S202 was observed in Cornu Ammonis 1 (CA1) hippocampal neuron soma of CTC compared to CTO brains. Eighteen-month-old CTC brains showed rare argentophilic deposits that increased by 25 months, whereas CTO brains only displayed them sparsely at 25 months. Tau microtubule binding was equivalent in CTC and CTO hippocampi. Episodic and spatial memory measured with novel object recognition and Barnes maze, respectively, remained normal in 3–25-month-old CTC and CTO mice, in contrast to previously observed impairments in ACL mice expressing equivalent levels of hCasp6 only. Consistently, the CTC and CTO hippocampal CA1 region displayed equivalent dendritic spine density and no glial inflammation. Together, these results reveal that active hCasp6 co-expression with hTau generates Tau cleavage and rare age-dependent argentophilic deposits but fails to induce cognitive deficits, neuroinflammation, and Tau pathology.

scholarly journals TheGαoActivator Mastoparan-7 Promotes Dendritic Spine Formation in Hippocampal Neurons

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Valerie T. Ramírez ◽  
Eva Ramos-Fernández ◽  
Nibaldo C. Inestrosa
Keyword(s):  
Protein Kinase ◽  
Dendritic Spine ◽  
Hippocampal Neurons ◽  
Biological Effects ◽  
Critical Role ◽  
Head Width ◽  
Dependent Manner ◽  
Spine Density ◽  
Dendritic Spine Density

Mastoparan-7 (Mas-7), an analogue of the peptide mastoparan, which is derived from wasp venom, is a direct activator ofPertussis toxin-(PTX-) sensitive G proteins. Mas-7 produces several biological effects in different cell types; however, little is known about how Mas-7 influences mature hippocampal neurons. We examined the specific role of Mas-7 in the development of dendritic spines, the sites of excitatory synaptic contact that are crucial for synaptic plasticity. We report here that exposure of hippocampal neurons to a low dose of Mas-7 increases dendritic spine density and spine head width in a time-dependent manner. Additionally, Mas-7 enhances postsynaptic density protein-95 (PSD-95) clustering in neurites and activatesGαosignaling, increasing the intracellular Ca2+concentration. To define the role of signaling intermediates, we measured the levels of phosphorylated protein kinase C (PKC), c-Jun N-terminal kinase (JNK), and calcium-calmodulin dependent protein kinase IIα(CaMKIIα) after Mas-7 treatment and determined that CaMKII activation is necessary for the Mas-7-dependent increase in dendritic spine density. Our results demonstrate a critical role forGαosubunit signaling in the regulation of synapse formation.

scholarly journals Endocannabinoid- and mGluR5-Dependent Short-Term Synaptic Depression in an Isolated Neuron/Bouton Preparation From the Hippocampal CA1 Region

2008 ◽  
Vol 100 (2) ◽  
pp. 1041-1052 ◽  
Author(s):  
Anton Sheinin ◽  
Giuseppe Talani ◽  
Margaret I. Davis ◽  
David M. Lovinger
Keyword(s):  
Hippocampal Neurons ◽  
Basolateral Amygdala ◽  
Pyramidal Neurons ◽  
Metabotropic Glutamate Receptor ◽  
Hippocampal Slices ◽  
Neuronal Membrane ◽  
Short Term ◽  
Ca1 Region ◽  
Hippocampal Ca1 Region ◽  
Isolated Neuron

Endocannabinoids released from the postsynaptic neuronal membrane can activate presynaptic CB1 receptors and inhibit neurotransmitter release. In hippocampal slices, depolarization of the CA1 pyramidal neurons elicits an endocannabinoid-mediated inhibition of γ-aminobutyric acid release known as depolarization-induced suppression of inhibition (DSI). Using the highly reduced neuron/synaptic bouton preparation from the CA1 region of hippocampus, we have begun to examine endocannabinoid-dependent short-term depression (STD) of inhibitory synaptic transmission under well-controlled physiological and pharmacological conditions in an environment free of other cells. Application of the CB1 synthetic agonist WIN55212 -2 and endogenous cannabinoids 2-AG and anandamide produced a decrease in spontaneous inhibitory postsynaptic current (sIPSC) frequency and amplitude, indicating the presence of CB1 receptors at synapses in this preparation. Endocannabinoid-dependent STD is different from DSI found in hippocampal slices and the neuron/bouton preparation from basolateral amygdala (BLA) since depolarization alone was not sufficient to induce suppression of sIPSCs. However, concurrent application of the metabotropic glutamate receptor (mGluR) agonist ( RS)-3,5-dihydroxyphenylglycine (DHPG) and postsynaptic depolarization resulted in a transient (30–50 s) decrease in sIPSC frequency and amplitude. Application of DHPG alone had no effect on sIPSCs. The depolarization/DHPG-induced STD was blocked by the CB1 antagonist SR141716A and the mGluR5 antagonist MPEP and was sensitive to intracellular calcium concentration. Comparing the present findings with earlier work in hippocampal slices and BLA, it appears that endocannabinoid release is less robust in isolated hippocampal neurons.

Rapid Effects of Estradiol on Dendritic Spines and Synaptic Plasticity in the Male and Female Hippocampus

2020 ◽  
pp. 38-47
Author(s):  
Asami Kato ◽  
Gen Murakami ◽  
Yasushi Hojo ◽  
Sigeo Horie ◽  
Suguru Kawato
Keyword(s):  
Synaptic Plasticity ◽  
Dendritic Spine ◽  
Hippocampal Neurons ◽  
Molecular Mechanisms ◽  
Hippocampal Slices ◽  
Spine Density ◽  
Male And Female ◽  
Dendritic Spine Density ◽  
Male And Female Rats ◽  
Rapid Modulation

Although the potent estrogen, 17β‎-estradiol (E2), has long been known to regulate the hippocampal dendritic spine density and synaptic plasticity, the molecular mechanisms through which it does so are less well understood. This chapter discusses the rapid modulation of hippocampal dendritic spine density and synaptic plasticity in male and female rats, with particular attention to studies in hippocampal slices from male rats. Among the mechanisms described are the roles of specific cell-signaling kinases and estrogen receptors in mediating the effects of E2 and progesterone on hippocampal neurons. In addition, dynamic changes of spine structures over time and sex differences in spine regulation are also considered. Finally, the chapter ends by discussing the importance of local hippocampal synthesis of E2 and androgens to hippocampal spine morphology and plasticity.

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