scholarly journals Cellular and molecular mechanisms in the long-term action of antidepressants

2008 ◽  
Vol 10 (4) ◽  
pp. 385-400 ◽  
Keyword(s):  
Gene Expression ◽  
Synaptic Transmission ◽  
Mood Disorders ◽  
Molecular Mechanisms ◽  
Final Section ◽  
Therapeutic Action ◽  
Temporal Delay ◽  
Current Version ◽  
Lines Of Evidence

The hypotheses on the pathophysiology of depression/mood disorders and on antidepressant mechanisms have greatly changed in recent years. The classical monoamine hypothesis was revealed to be simplistic, in that it could not explain the temporal delay in the therapeutic action of antidepressants. Converging lines of evidence have shown that adaptive changes in the several mechanisms of neuroplasticity are likely to be the cellular and molecular correlates of therapeutic effect. In this article, several mechanisms of neuroplasticity are analyzed in relation to the mechanism of antidepressants, ranging from changes in gene expression (including neurotrophic mechanisms), to synaptic transmission and plasticity, and neurogenesis. We propose that the current version of the hypothesis of antidepressant mechanism simply be called the "hypothesis of neuroplasticity". In the final section, we also briefly review the main current novel strategies in the pharmacology of depression and the new putative targets for antidepressants, with particular emphasis on nonmonoaminergic mechanisms.

scholarly journals Transcriptome-wide gene expression plasticity in Stipa grandis in response to grazing intensity differences

2020 ◽  
Author(s):  
Zhenhua Dang ◽  
Yuanyuan Jia ◽  
Yunyun Tian ◽  
Jiabin Li ◽  
Yanan Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Metabolic Pathways ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Grazing Intensity ◽  
Glycolate Oxidase ◽  
Bisphosphate Carboxylase ◽  
Grazing Intensities

Organisms have evolved effective and distinct adaptive strategies to survive. Stipa grandis is one of the widespread dominant species on the typical steppe of the Inner Mongolian Plateau, and is regarded as a suitable species for studying the effects of grazing in this region. Although phenotypic (morphological and physiological) variations in S. grandis in response to long-term grazing have been identified, the molecular mechanisms underlying adaptations and plastic responses remain largely unknown. Accordingly, we performed a transcriptomic analysis to investigate changes in gene expression of S. grandis under four different grazing intensities. A total of 2,357 differentially expressed genes (DEGs) were identified among the tested grazing intensities, suggesting long-term grazing resulted in gene expression plasticity that affected diverse biological processes and metabolic pathways in S. grandis. DEGs were identified that indicated modulation of Calvin–Benson cycle and photorespiration metabolic pathways. The key gene´expression profiles encoding various proteins (e.g., Ribulose-1,5-bisphosphate carboxylase/oxygenase, fructose-1,6-bisphosphate aldolase, glycolate oxidase etc.) involved in these pathways suggest that they may synergistically respond to grazing to increase the resilience and stress tolerance of S. grandis. Our findings provide scientific clues for improving grassland use and protection, and identify important questions to address in future transcriptome studies.

scholarly journals Transcriptional signatures throughout development: the effects of mouse embryo manipulation in vitro

Reproduction ◽  
2017 ◽  
Vol 153 (1) ◽  
pp. 107-122 ◽  
Author(s):  
Sky K Feuer ◽  
Xiaowei Liu ◽  
Annemarie Donjacour ◽  
Rhodel Simbulan ◽  
Emin Maltepe ◽  
...  
Keyword(s):  
Gene Expression ◽  
Molecular Mechanisms ◽  
Preimplantation Embryo ◽  
Environmental Exposures ◽  
Developmental Time ◽  
Transcriptional Responses ◽  
Transcriptional Changes ◽  
Specific Impact

Stressful environmental exposures incurred early in development can affect postnatal metabolic health and susceptibility to non-communicable diseases in adulthood, although the molecular mechanisms by which this occurs have yet to be elucidated. Here, we use a mouse model to investigate how assortedin vitroexposures restricted exclusively to the preimplantation period affect transcription both acutely in embryos and long term in subsequent offspring adult tissues, to determine if reliable transcriptional markers ofin vitrostress are present at specific developmental time points and throughout development. Eachin vitrofertilization or embryo culture environment led to a specific and unique blastocyst transcriptional profile, but we identified a common 18-gene and 9-pathway signature of preimplantation embryo manipulation that was present in allin vitroembryos irrespective of culture condition or method of fertilization. This fingerprint did not persist throughout development, and there was no clear transcriptional cohesion between adult IVF offspring tissues or compared to their preceding embryos, indicating a tissue-specific impact ofin vitrostress on gene expression. However, the transcriptional changes present in each IVF tissue were targeted by the same upstream transcriptional regulators, which provide insight as to how acute transcriptional responses to stressful environmental exposures might be preserved throughout development to influence adult gene expression.

scholarly journals Potentiation of amyloid beta phagocytosis and amelioration of synaptic dysfunction upon FAAH deletion in a mouse model of Alzheimer's disease

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Gonzalo Ruiz-Pérez ◽  
Samuel Ruiz de Martín Esteban ◽  
Sharai Marqués ◽  
Noelia Aparicio ◽  
M. Teresa Grande ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Model ◽  
Synaptic Transmission ◽  
Amyloid Beta ◽  
Molecular Mechanisms ◽  
Long Term Potentiation ◽  
Genetic Inactivation ◽  
5Xfad Mouse

Abstract Background The complex pathophysiology of Alzheimer’s disease (AD) hampers the development of effective treatments. Attempts to prevent neurodegeneration in AD have failed so far, highlighting the need for further clarification of the underlying cellular and molecular mechanisms. Neuroinflammation seems to play a crucial role in disease progression, although its specific contribution to AD pathogenesis remains elusive. We have previously shown that the modulation of the endocannabinoid system (ECS) renders beneficial effects in a context of amyloidosis, which triggers neuroinflammation. In the 5xFAD model, the genetic inactivation of the enzyme that degrades anandamide (AEA), the fatty acid amide hydrolase (FAAH), was associated with a significant amelioration of the memory deficit. Methods In this work, we use electrophysiology, flow cytometry and molecular analysis to evaluate the cellular and molecular mechanisms underlying the improvement associated to the increased endocannabinoid tone in the 5xFAD mouse− model. Results We demonstrate that the chronic enhancement of the endocannabinoid tone rescues hippocampal synaptic plasticity in the 5xFAD mouse model. At the CA3–CA1 synapse, both basal synaptic transmission and long-term potentiation (LTP) of synaptic transmission are normalized upon FAAH genetic inactivation, in a CB1 receptor (CB1R)- and TRPV1 receptor-independent manner. Dendritic spine density in CA1 pyramidal neurons, which is notably decreased in 6-month-old 5xFAD animals, is also restored. Importantly, we reveal that the expression of microglial factors linked to phagocytic activity, such as TREM2 and CTSD, and other factors related to amyloid beta clearance and involved in neuron–glia crosstalk, such as complement component C3 and complement receptor C3AR, are specifically upregulated in 5xFAD/FAAH−/− animals. Conclusion In summary, our findings support the therapeutic potential of modulating, rather than suppressing, neuroinflammation in Alzheimer’s disease. In our model, the long-term enhancement of the endocannabinoid tone triggered augmented microglial activation and amyloid beta phagocytosis, and a consequent reversal in the neuronal phenotype associated to the disease.

scholarly journals Comparative Transcriptome Analysis Provides Insights into The Response of Ulva Compressa to The Fluctuating Salinity Conditions

2020 ◽  
Author(s):  
Qikun Xing ◽  
Guiqi Bi ◽  
Min Cao ◽  
Arnaud Belcour ◽  
Méziane Aite ◽  
...  
Keyword(s):  
Gene Expression ◽  
Salinity Stress ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Green Tide ◽  
Saline Stress ◽  
Ulva Compressa ◽  
A Genome ◽  
Differently Expressed Genes

Abstract Background: Ulva compressa, known as the green tide forming species, was reported that can adapt to hypo-salinity conditions such as estuaries and brackish lakes. To understand the underlying molecular mechanisms of hypo-salinity stress tolerance, a genome-wide gene expression profiles in U. compressa was performed using digital gene expression profile (DGE). Results: The RNA-seq data were analyzed based on the comparison of differently expressed genes involved in specific pathways under hypo-salinity and recovery conditions. Under the long-term hypo-salinity stress, the recovery of photosynthesis and energy metabolism could provide sufficient energy for the tolerance under long-term hypo-saline stress. Multiple strategies were performed to maintain the osmotic homeostasis. Additionally, several long non-coding RNA were detected as differently expressed genes during the stress, which could play important roles in the osmotolerance. Conclusions: Our work will serve as an essential foundation for the understanding of the tolerance mechanism of U. compressa under the fluctuating salinity conditions.

scholarly journals Inhibition of RANKL and Sema4d Improves Residual Ridge Resorption in Mice.

2022 ◽  
Author(s):  
Meri Hisamoto ◽  
Shunsuke Kimura ◽  
Kai Iwata ◽  
Toshihiko Iwanaga ◽  
Atsuro Yokoyama
Keyword(s):  
Gene Expression ◽  
Bone Loss ◽  
Molecular Mechanisms ◽  
Alveolar Bone ◽  
Alveolar Bone Loss ◽  
Period Gene ◽  
Semaphorin 4D ◽  
Long Time ◽  
Extraction Model

Abstract Residual ridge resorption (RRR) is a chronic and progressive bone resorption following tooth loss. It causes deterioration of the oral environments and leads to the pathogenesis of various systemic diseases. However, the molecular mechanisms and risk factors for RRR progression are still unclear and controversial. In this study, we developed a tooth extraction model using mice for analyzing long-term morphological and gene expression changes in the alveolar bone. We further applied ovariectomy to this model to elucidate the effects of osteoporosis on RRR progression. As a result, the alveolar bone loss was biphasic and consisted of rapid loss in the early stages and subsequently slow and sustained bone loss over a long period. Gene expression analysis indicated that ovariectomy increased the expression of pro-inflammatory cytokines in the alveolar bone and prolonged the activation of osteoclasts same as histological analysis. Furthermore, the expressions of Tnfsf11 and Sema4d kept increasing for a long time in OVX mice. Administration of neutralization antibodies for receptor activator of NF-κB ligand (RANKL) effectively suppressed RRR. Similarly, inhibition of Semaphorin 4d (Sema4d) also improved alveolar bone loss. This study demonstrated that osteoporosis is a risk factor for RRR and that RANKL and Sema4d suppression are potential treatments.

scholarly journals Specific nanoscale synaptic reshuffling and control of short-term plasticity following NMDAR- and P2XR-dependent Long-Term Depression

2019 ◽  
Author(s):  
Benjamin Compans ◽  
Magalie Martineau ◽  
Remco V. Klaassen ◽  
Thomas M. Bartol ◽  
Corey Butler ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Molecular Mechanisms ◽  
Super Resolution ◽  
Long Term Potentiation ◽  
Global Changes ◽  
Short Term ◽  
Long Term Depression ◽  
Term Potentiation ◽  
And Control

Long-Term Potentiation (LTP) and Long-Term Depression (LTD) of excitatory synaptic transmission are considered as cellular basis of learning and memory. These two forms of synaptic plasticity have been mainly attributed to global changes in the number of synaptic AMPA-type glutamate receptor (AMPAR) through a regulation of the diffusion/trapping balance at the PSD, exocytosis and endocytosis. While the precise molecular mechanisms at the base of LTP have been intensively investigated, the ones involved in LTD remains elusive. Here we combined super-resolution imaging technique, electrophysiology and modeling to describe the various modifications of AMPAR nanoscale organization and their effect on synaptic transmission in response to two different LTD protocols, based on the activation of either NMDA receptors or P2X receptors. While both type of LTD are associated with a decrease in synaptic AMPAR clustering, only NMDAR-dependent LTD is associated with a reorganization of PSD-95 at the nanoscale. This change increases the pool of diffusive AMPAR improving synaptic short-term facilitation through a post-synaptic mechanism. These results demonstrate that specific dynamic reorganization of synapses at the nanoscale during specific LTD paradigm allows to improve the responsiveness of depressed synapses.

Effects of general anesthetics on synaptic transmission and plasticity

2021 ◽  
Vol 19 ◽  
Author(s):  
Jimcy Platholi ◽  
Hugh C. Hemmings Jr
Keyword(s):  
Synaptic Transmission ◽  
Molecular Mechanisms ◽  
Anesthetic Agent ◽  
General Anesthetics ◽  
General Anesthetic ◽  
Synaptic Structure ◽  
Gabaergic Synapses ◽  
Voltage Gated Ion Channels ◽  
Higher Order Functions

: General anesthetics depress excitatory and/or enhance inhibitory synaptic transmission principally by modulating the function of glutamatergic or GABAergic synapses, respectively, with relative anesthetic agent-specific mechanisms. Synaptic signaling proteins, including ligand- and voltage-gated ion channels, are targeted by general anesthetics to modulate various synaptic mechanisms including presynaptic neurotransmitter release, postsynaptic receptor signaling, and dendritic spine dynamics to produce their characteristic acute neurophysiological effects. As synaptic structure and plasticity mediate higher-order functions such as learning and memory, long-term synaptic dysfunction following anesthesia may lead to undesirable neurocognitive consequences depending on specific anesthetic agent and the vulnerability of population. Here we review the cellular and molecular mechanisms of transient and persistent general anesthetic alterations of synaptic transmission and plasticity.

scholarly journals Contrasting growth, physiological and gene expression responses of Clematis crassifolia and Clematis cadmia to different irradiance conditions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiaohua Ma ◽  
Renjuan Qian ◽  
Xule Zhang ◽  
Qingdi Hu ◽  
Hongjian Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Superoxide Dismutase ◽  
Molecular Mechanisms ◽  
High Irradiance ◽  
Soluble Protein Content ◽  
Term Evolution ◽  
Catalase Peroxidase ◽  
Contrasting Habitats ◽  
Different Levels

AbstractClematis crassifolia and Clematis cadmia Buch.-Ham. ex Hook.f. & Thomson are herbaceous vine plants native to China. C. crassifolia is distributed in shaded areas, while C. cadmia mostly grows in bright, sunny conditions in mountainous and hilly landscapes. To understand the potential mechanisms involved in the irradiance responses of C. crassifolia and C. cadmia, we conducted a pot experiment under three irradiance treatments with natural irradiation and two different levels of shading. Various growth, photosynthetic, oxidative and antioxidative parameters and the relative expression of irradiance-related genes were examined. In total, 15 unigenes were selected for the analysis of gene expression. The exposure of C. crassifolia to high irradiance resulted in growth inhibition coupled with increased levels of chlorophyll, increased catalase, peroxidase, and superoxide dismutase activity and increased expression of c144262_g2, c138393_g1 and c131300_g2. In contrast, under high irradiance conditions, C. cadmia showed an increase in growth and soluble protein content accompanied by a decrease in the expression of c144262_g2, c133872_g1, and c142530_g1, suggesting their role in the acclimation of C. cadmia to a high-irradiance environment. The 15 unigenes were differentially expressed in C. crassifolia and C. cadmia under different irradiance conditions. Thus, our study revealed that there are essential differences in the irradiance adaptations of C. crassifolia and C. cadmia due to the differential physiological and molecular mechanisms underlying their irradiance responses, which result from their long-term evolution in contrasting habitats.

Genes to remember

1999 ◽  
Vol 202 (21) ◽  
pp. 2887-2891
Author(s):  
C.M. Alberini
Keyword(s):  
Gene Expression ◽  
Molecular Mechanisms ◽  
Camp Response Element Binding ◽  
Long Term Memory ◽  
Biological Mechanisms ◽  
Camp Response Element ◽  
Term Memory ◽  
Molecular Approaches ◽  
Complex Forms

It has been known for several decades that the formation of long-term memory requires gene expression. In recent years, the use of genetic and molecular approaches has led to the identification and characterization of genes and molecules that play a fundamental role in the biological mechanisms underlying learning and memory. From these studies, it appears that molecules and molecular mechanisms essential for the process of memory have been conserved throughout evolution. The cyclic AMP (cAMP)-dependent activation pathway and a cAMP-dependent cascade of gene expression have been shown to be essential for memory formation in Aplysia californica, Drosophila melanogaster and rodents. Moreover, members of the transcription factor family cAMP response element binding proteins (CREBs) seem to represent key molecules for transforming incoming information into long-term memory. Here, we review the studies showing that conserved molecules and biological mechanisms are engaged in simple and complex forms of memory.

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