scholarly journals Environmental Enrichment Rescues Social Behavioral Deficits and Synaptic Abnormalities in Pten Haploinsufficient Mice

Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1366
Author(s):  
Amy E. Clipperton-Allen ◽  
Angela Zhang ◽  
Ori S. Cohen ◽  
Damon Theron Page
Keyword(s):  
Synaptic Plasticity ◽  
Environmental Enrichment ◽  
Repetitive Behavior ◽  
Synaptic Proteins ◽  
Protein Abundance ◽  
Synaptic Protein ◽  
Wild Type ◽  
Neuronal Connectivity ◽  
Behavioral Deficits ◽  
Adult Mice

Pten germline haploinsufficient (Pten+/−) mice, which model macrocephaly/autism syndrome, show social and repetitive behavior deficits, early brain overgrowth, and cortical–subcortical hyperconnectivity. Previous work indicated that altered neuronal connectivity may be a substrate for behavioral deficits. We hypothesized that exposing Pten+/− mice to environmental enrichment after brain overgrowth has occurred may facilitate adaptation to abnormal “hard-wired” connectivity through enhancing synaptic plasticity. Thus, we reared Pten+/− mice and their wild-type littermates from weaning under either standard (4–5 mice per standard-sized cage, containing only bedding and nestlet) or enriched (9–10 mice per large-sized cage, containing objects for exploration and a running wheel, plus bedding and nestlet) conditions. Adult mice were tested on social and non-social assays in which Pten+/− mice display deficits. Environmental enrichment rescued sex-specific deficits in social behavior in Pten+/− mice and partially rescued increased repetitive behavior in Pten+/− males. We found that Pten+/− mice show increased excitatory and decreased inhibitory pre-synaptic proteins; this phenotype was also rescued by environmental enrichment. Together, our results indicate that environmental enrichment can rescue social behavioral deficits in Pten+/− mice, possibly through normalizing the excitatory synaptic protein abundance.

scholarly journals Trem2 Y38C Mutation and Loss of Trem2 Impairs Neuronal Synapses in Adult Mice

2020 ◽  
Author(s):  
Vaishnavi S. Jadhav ◽  
Peter BC. Lin ◽  
Guixiang Xu ◽  
Taylor Pennington ◽  
Gonzalo Viana Di Prisco ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Synaptic Plasticity ◽  
Late Onset ◽  
Synaptic Proteins ◽  
Synaptic Protein ◽  
Presenile Dementia ◽  
Altered Expression ◽  
Protein Levels

Abstract Background:Triggering receptor expressed on myeloid cells 2 (TREM2) is expressed in the brain exclusively on microglia and genetic variants are linked to neurodegenerative diseases including Alzheimer’s disease (AD), frontotemporal dementia (FTD) and NasuHakola Disease (NHD). The Trem2 variantR47H, confers substantially elevated risk of developing late onset Alzheimer’s disease, while NHD-linkedTrem2 variants like Y38Care associated with development of early onset dementia with white matter pathology. However, it is not known how these Trem2species predispose individuals to presenile dementia.Methods:To investigate if Trem2 Y38C or loss of Trem2 alters neuronal function, we generated a novel mouse model to introduce the NHD Trem2 Y38C variant in murine Trem2 using CRISPR/Cas9 technology. Trem2Y38/Y38C and Trem2-/-mice were assessed for Trem2 expression, differentially expressed genes, synaptic protein levels and synaptic plasticity using biochemical, electrophysiological and transcriptomic approaches.Results:While mice harboring Trem2 Y38C exhibited normal expression levels of Trem2, the pathological outcomes phenocopied Trem2-/- miceat 6 months. Transcriptomic analysis revealed altered expression of neuronal and oligodendrocytes/myelin genes. We observed regional decreases in synaptic protein levels, with the most affected synapses in the hippocampus. These alterations were associated with reduced synaptic plasticity. Conclusion:Our findings provide in vivo evidence that Trem2 Y38C disrupts normal TREM2 functions. Trem2Y38C/Y38Cand Trem2-/- mice demonstrated altered gene expression, changes in microglia morphology, loss of synaptic proteins and reduced hippocampal synaptic plasticity at 6 months in absence of any pathological triggers like tau or amyloid. This suggests TREM2 impacts neuronal functions and providesmolecular insights on the predisposition of individuals with TREM2 variants resulting in presenile dementia.

scholarly journals Trem2 Y38C mutation and loss of Trem2 impairs neuronal synapses in adult mice

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Vaishnavi S. Jadhav ◽  
Peter B. C. Lin ◽  
Taylor Pennington ◽  
Gonzalo Viana Di Prisco ◽  
Asha Jacob Jannu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Synaptic Plasticity ◽  
Late Onset ◽  
Synaptic Proteins ◽  
Synaptic Protein ◽  
Presenile Dementia ◽  
Altered Expression ◽  
Protein Levels

Abstract Background Triggering receptor expressed on myeloid cells 2 (TREM2) is expressed in the brain exclusively on microglia and genetic variants are linked to neurodegenerative diseases including Alzheimer’s disease (AD), frontotemporal dementia (FTD) and Nasu Hakola Disease (NHD). The Trem2 variant R47H, confers substantially elevated risk of developing late onset Alzheimer’s disease, while NHD-linked Trem2 variants like Y38C, are associated with development of early onset dementia with white matter pathology. However, it is not known how these Trem2 species, predisposes individuals to presenile dementia. Methods To investigate if Trem2 Y38C or loss of Trem2 alters neuronal function we generated a novel mouse model to introduce the NHD Trem2 Y38C variant in murine Trem2 using CRISPR/Cas9 technology. Trem2Y38C/Y38C and Trem2−/− mice were assessed for Trem2 expression, differentially expressed genes, synaptic protein levels and synaptic plasticity using biochemical, electrophysiological and transcriptomic approaches. Results While mice harboring the Trem2 Y38C exhibited normal expression levels of TREM2, the pathological outcomes phenocopied Trem2−/− mice at 6 months. Transcriptomic analysis revealed altered expression of neuronal and oligodendrocytes/myelin genes. We observed regional decreases in synaptic protein levels, with the most affected synapses in the hippocampus. These alterations were associated with reduced synaptic plasticity. Conclusion Our findings provide in vivo evidence that Trem2 Y38C disrupts normal TREM2 functions. Trem2Y38C/Y38C and Trem2−/− mice demonstrated altered gene expression, changes in microglia morphology, loss of synaptic proteins and reduced hippocampal synaptic plasticity at 6 months in absence of any pathological triggers like amyloid. This suggests TREM2 impacts neuronal functions providing molecular insights on the predisposition of individuals with TREM2 variants resulting in presenile dementia.

scholarly journals Trem2 Y38C mutation and loss of Trem2 impairs neuronal synapses in adult mice

2020 ◽  
Author(s):  
Vaishnavi S. Jadhav ◽  
Peter BC. Lin ◽  
Taylor Pennington ◽  
Gonzalo Viana Di Prisco ◽  
Asha Jacob Jannu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Synaptic Plasticity ◽  
Late Onset ◽  
Synaptic Proteins ◽  
Synaptic Protein ◽  
Presenile Dementia ◽  
Altered Expression ◽  
Protein Levels

Abstract Background: Triggering receptor expressed on myeloid cells 2 (TREM2) is expressed in the brain exclusively on microglia and genetic variants are linked to neurodegenerative diseases including Alzheimer’s disease (AD), frontotemporal dementia (FTD) and Nasu Hakola Disease (NHD). The Trem2 variant R47H, confers substantially elevated risk of developing late onset Alzheimer’s disease, while NHD-linked Trem2 variants like Y38C, are associated with development of early onset dementia with white matter pathology. However, it is not known how these Trem2 species, predisposes individuals to presenile dementia.Methods: To investigate if Trem2 Y38C or loss of Trem2 alters neuronal function we generated a novel mouse model to introduce the NHD Trem2 Y38C variant in murine Trem2 using CRISPR/Cas9 technology. Trem2Y38C/Y38C and Trem2-/- mice were assessed for Trem2 expression, differentially expressed genes, synaptic protein levels and synaptic plasticity using biochemical, electrophysiological and transcriptomic approaches.Results: While mice harboring the Trem2 Y38C exhibited normal expression levels of TREM2, the pathological outcomes phenocopied Trem2-/- mice at 6 months. Transcriptomic analysis revealed altered expression of neuronal and oligodendrocytes/myelin genes. We observed regional decreases in synaptic protein levels, with the most affected synapses in the hippocampus. These alterations were associated with reduced synaptic plasticity. Conclusion: Our findings provide in vivo evidence that Trem2 Y38C disrupts normal TREM2 functions. Trem2Y38C/Y38C and Trem2-/- mice demonstrated altered gene expression, changes in microglia morphology, loss of synaptic proteins and reduced hippocampal synaptic plasticity at 6 months in absence of any pathological triggers like amyloid. This suggests TREM2 impacts neuronal functions providing molecular insights on the predisposition of individuals with TREM2 variants resulting in presenile dementia.

scholarly journals Caffeine acts through neuronal adenosine A2A receptors to prevent mood and memory dysfunction triggered by chronic stress

2015 ◽  
Vol 112 (25) ◽  
pp. 7833-7838 ◽  
Author(s):  
Manuella P. Kaster ◽  
Nuno J. Machado ◽  
Henrique B. Silva ◽  
Ana Nunes ◽  
Ana Paula Ardais ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Chronic Stress ◽  
Memory Performance ◽  
Glutamate Transporter ◽  
Synaptic Proteins ◽  
Adenosine Receptor Antagonist ◽  
A2a Receptors ◽  
Adult Mice ◽  
Reduced Density ◽  
Adenosine A2a

The consumption of caffeine (an adenosine receptor antagonist) correlates inversely with depression and memory deterioration, and adenosine A2A receptor (A2AR) antagonists emerge as candidate therapeutic targets because they control aberrant synaptic plasticity and afford neuroprotection. Therefore we tested the ability of A2AR to control the behavioral, electrophysiological, and neurochemical modifications caused by chronic unpredictable stress (CUS), which alters hippocampal circuits, dampens mood and memory performance, and enhances susceptibility to depression. CUS for 3 wk in adult mice induced anxiogenic and helpless-like behavior and decreased memory performance. These behavioral changes were accompanied by synaptic alterations, typified by a decrease in synaptic plasticity and a reduced density of synaptic proteins (synaptosomal-associated protein 25, syntaxin, and vesicular glutamate transporter type 1), together with an increased density of A2AR in glutamatergic terminals in the hippocampus. Except for anxiety, for which results were mixed, CUS-induced behavioral and synaptic alterations were prevented by (i) caffeine (1 g/L in the drinking water, starting 3 wk before and continued throughout CUS); (ii) the selective A2AR antagonist KW6002 (3 mg/kg, p.o.); (iii) global A2AR deletion; and (iv) selective A2AR deletion in forebrain neurons. Notably, A2AR blockade was not only prophylactic but also therapeutically efficacious, because a 3-wk treatment with the A2AR antagonist SCH58261 (0.1 mg/kg, i.p.) reversed the mood and synaptic dysfunction caused by CUS. These results herald a key role for synaptic A2AR in the control of chronic stress-induced modifications and suggest A2AR as candidate targets to alleviate the consequences of chronic stress on brain function.

scholarly journals VAMP-2 is a surrogate cerebrospinal fluid marker of Alzheimer-related cognitive impairment in adults with Down syndrome

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Alberto Lleó ◽  
Maria Carmona-Iragui ◽  
Laura Videla ◽  
Susana Fernández ◽  
Bessy Benejam ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Down Syndrome ◽  
Cognitive Impairment ◽  
Episodic Memory ◽  
Cognitive Performance ◽  
Synaptic Proteins ◽  
Selected Reaction Monitoring ◽  
Synaptic Protein ◽  
Csf Levels ◽  
Syntaxin 1B

Abstract Background There is an urgent need for objective markers of Alzheimer’s disease (AD)-related cognitive impairment in people with Down syndrome (DS) to improve diagnosis, monitor disease progression, and assess response to disease-modifying therapies. Previously, GluA4 and neuronal pentraxin 2 (NPTX2) showed limited potential as cerebrospinal fluid (CSF) markers of cognitive impairment in adults with DS. Here, we compare the CSF profile of a panel of synaptic proteins (Calsyntenin-1, Neuroligin-2, Neurexin-2A, Neurexin-3A, Syntaxin-1B, Thy-1, VAMP-2) to that of NPTX2 and GluA4 in a large cohort of subjects with DS across the preclinical and clinical AD continuum and explore their correlation with cognitive impairment. Methods We quantified the synaptic panel proteins by selected reaction monitoring in CSF from 20 non-trisomic cognitively normal controls (mean age 44) and 80 adults with DS grouped according to clinical AD diagnosis (asymptomatic, prodromal AD or AD dementia). We used regression analyses to determine CSF changes across the AD continuum and explored correlations with age, global cognitive performance (CAMCOG), episodic memory (modified cued-recall test; mCRT) and CSF biomarkers, CSF Aβ42:40 ratio, CSF Aβ1-42, CSF p-tau, and CSF NFL. P values were adjusted for multiple testing. Results In adults with DS, VAMP-2 was the only synaptic protein to correlate with episodic memory (delayed recall adj.p = .04) and age (adj.p = .0008) and was the best correlate of CSF Aβ42:40 (adj.p = .0001), p-tau (adj.p < .0001), and NFL (adj.p < .0001). Compared to controls, mean VAMP-2 levels were lower in asymptomatic adults with DS only (adj.p = .02). CSF levels of Neurexin-3A, Thy-1, Neurexin-2A, Calysntenin-1, Neuroligin-2, GluA4, and Syntaxin-1B all strongly correlated with NPTX2 (p < .0001), which was the only synaptic protein to show reduced CSF levels in DS at all AD stages compared to controls (adj.p < .002). Conclusion These data show proof-of-concept for CSF VAMP-2 as a potential marker of synapse degeneration that correlates with CSF AD and axonal degeneration markers and cognitive performance.

scholarly journals Protein synthesis in the dendrite

2002 ◽  
Vol 357 (1420) ◽  
pp. 521-529 ◽  
Author(s):  
Shao Jun Tang ◽  
Erin M. Schuman
Keyword(s):  
Protein Synthesis ◽  
Neural Plasticity ◽  
Messenger Rna ◽  
Mrna Translation ◽  
Synaptic Activity ◽  
Synaptic Proteins ◽  
Local Source ◽  
Synaptic Protein ◽  
Specific Proteins ◽  
Molecular Nature

In neurons, many proteins that are involved in the transduction of synaptic activity and the expression of neural plasticity are specifically localized at synapses. How these proteins are targeted is not clearly understood. One mechanism is synaptic protein synthesis. According to this idea, messenger RNA (mRNA) translation from the polyribosomes that are observed at the synaptic regions provides a local source of synaptic proteins. Although an increasing number of mRNA species has been detected in the dendrite, information about the synaptic synthesis of specific proteins in a physiological context is still limited. The physiological function of synaptic synthesis of specific proteins in synaptogenesis and neural plasticity expression remains to be shown. Experiments aimed at understanding the mechanisms and functions f synaptic protein synthesis might provide important information about the molecular nature of neural plasticity.

scholarly journals Radixin deficiency causes deafness associated with progressive degeneration of cochlear stereocilia

2004 ◽  
Vol 166 (4) ◽  
pp. 559-570 ◽  
Author(s):  
Shin-ichiro Kitajiri ◽  
Kanehisa Fukumoto ◽  
Masaki Hata ◽  
Hiroyuki Sasaki ◽  
Tatsuya Katsuno ◽  
...  
Keyword(s):  
Hair Cells ◽  
Plasma Membranes ◽  
Wild Type ◽  
Cross Link ◽  
Erm Proteins ◽  
Hearing Ability ◽  
Adult Mice ◽  
Progressive Degeneration ◽  
Sensory Hair Cells

Ezrin/radixin/moesin (ERM) proteins cross-link actin filaments to plasma membranes to integrate the function of cortical layers, especially microvilli. We found that in cochlear and vestibular sensory hair cells of adult wild-type mice, radixin was specifically enriched in stereocilia, specially developed giant microvilli, and that radixin-deficient (Rdx−/−) adult mice exhibited deafness but no obvious vestibular dysfunction. Before the age of hearing onset (∼2 wk), in the cochlea and vestibule of Rdx−/− mice, stereocilia developed normally in which ezrin was concentrated. As these Rdx−/− mice grew, ezrin-based cochlear stereocilia progressively degenerated, causing deafness, whereas ezrin-based vestibular stereocilia were maintained normally in adult Rdx−/− mice. Thus, we concluded that radixin is indispensable for the hearing ability in mice through the maintenance of cochlear stereocilia, once developed. In Rdx−/− mice, ezrin appeared to compensate for radixin deficiency in terms of the development of cochlear stereocilia and the development/maintenance of vestibular stereocilia. These findings indicated the existence of complicate functional redundancy in situ among ERM proteins.

Maternal care and environmental enrichment influences on serotonin knockout mice with implications for a gene x stress model of autism

2019 ◽  
Author(s):  
◽  
Briana M. Kille
Keyword(s):  
Serotonin Transporter ◽  
Maternal Care ◽  
Environmental Enrichment ◽  
Environmental Influence ◽  
Repetitive Behavior ◽  
Critical Time ◽  
University Of Missouri ◽  
Time Period ◽  
Maternal Genotype ◽  
The University

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Previous research has shown a genetic variant in the serotonin transporter gene (Slc6a4) can increase the severity of a person's reaction to stress. This variant interacts with environmental stressors resulting in poorer health outcomes. Previous studies have also found that stressing pregnant mothers who carry the variant can result in an increased likelihood of autism diagnosis for the child. This maternal genotype x prenatal stress interaction has been modeled in the serotonin transporter knockout (SERT KO) mouse--dams genetically modified to mimic humans carrying the short allele were stressed during pregnancy resulting in offspring showing altered social behavior, repetitive behavior, and anxiety behavior. The first study included in this dissertation attempted to replicate this model while using a foster dam paradigm to avoid potential maternal care confounds. Surprisingly, the results showed that equalizing maternal care equalized several group differences in behavior. It is theorized that this is due to elimination of the neonatal insult from poor maternal care that would correspond to a human prenatal insult during a previously identified critical time period. The second study explored the potential effects environmentally enriched home cages on anxiety like behaviors of SERT KO mice. The study showed that all animals, regardless of genotype, showed fewer anxiety like behaviors in the open field assay. Together, these studies expand on our understanding of environmental influence on SERT KO mice used in translational studies.

Impaired wound healing in embryonic and adult mice lacking vimentin

2000 ◽  
Vol 113 (13) ◽  
pp. 2455-2462 ◽  
Author(s):  
B. Eckes ◽  
E. Colucci-Guyon ◽  
H. Smola ◽  
S. Nodder ◽  
C. Babinet ◽  
...  
Keyword(s):  
Wound Healing ◽  
Healing Process ◽  
Wild Type ◽  
Impaired Wound Healing ◽  
Wound Site ◽  
Adult Mice ◽  
Tractional Forces ◽  
Filament Network ◽  
Vimentin Intermediate Filament

It is generally assumed that the vimentin intermediate filament network present in most mesenchymally-derived cells is in part responsible for the strength and integrity of these cells, and necessary for any tissue movements that require the generation of significant tractional forces. Surprisingly, we have shown that transgenic KO mice deficient for vimentin are apparently able to undergo embryonic development absolutely normally and go onto develop into adulthood and breed without showing any obvious phenotype. However, fibroblasts derived from these mice are mechanically weak and severely disabled in their capacity to migrate and to contract a 3-D collagen network. To assess whether these functions are necessary for more challenging tissue movements such as those driving in vivo tissue repair processes, we have analysed wound healing ability in wild-type versus vimentin-deficient embryos and adult mice. Wounds in vimentin-deficient adult animals showed delayed migration of fibroblasts into the wound site and subsequently retarded contraction that correlated with a delayed appearance of myofibroblasts at the wound site. Wounds made to vimentin-deficient embryos also failed to heal during the 24 hour culture period it takes for wild-type embryos to fully heal an equivalent wound. By DiI marking the wound mesenchyme and following its fate during the healing process we showed that this impaired healing is almost entirely due to a failure of mesenchymal contraction at the embryonic wound site. These observations reveal an in vivo phenotype for the vimentin-deficient mouse, and challenge the dogma that key morphogenetic events occurring during development require generation of significant tractional forces by mesenchymal cells.

Sign in / Sign up

Export Citation Format

Share Document