scholarly journals Neuroligin 1 regulates spines and synaptic plasticity via LIMK1/cofilin-mediated actin reorganization

2016 ◽  
Vol 212 (4) ◽  
pp. 449-463 ◽  
Author(s):  
An Liu ◽  
Zikai Zhou ◽  
Rui Dang ◽  
Yuehua Zhu ◽  
Junxia Qi ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Synapse Development ◽  
Lim Domain ◽  
Actin Reorganization ◽  
Synaptic Regulation ◽  
Subsequent Activation ◽  
Guanosine Triphosphatase ◽  
Underlying Mechanisms ◽  
And Function ◽  
Activity Dependent

Neuroligin (NLG) 1 is important for synapse development and function, but the underlying mechanisms remain unclear. It is known that at least some aspects of NLG1 function are independent of the presynaptic neurexin, suggesting that the C-terminal domain (CTD) of NLG1 may be sufficient for synaptic regulation. In addition, NLG1 is subjected to activity-dependent proteolytic cleavage, generating a cytosolic CTD fragment, but the significance of this process remains unknown. In this study, we show that the CTD of NLG1 is sufficient to (a) enhance spine and synapse number, (b) modulate synaptic plasticity, and (c) exert these effects via its interaction with spine-associated Rap guanosine triphosphatase–activating protein and subsequent activation of LIM-domain protein kinase 1/cofilin–mediated actin reorganization. Our results provide a novel postsynaptic mechanism by which NLG1 regulates synapse development and function.

scholarly journals Regulation and Function of Activity-Dependent Homer in Synaptic Plasticity

2019 ◽  
Vol 5 (3) ◽  
pp. 147-161 ◽  
Author(s):  
Nicholas E. Clifton ◽  
Simon Trent ◽  
Kerrie L. Thomas ◽  
Jeremy Hall
Keyword(s):  
Synaptic Plasticity ◽  
And Function ◽  
Activity Dependent

scholarly journals Spindle Activity Orchestrates Plasticity during Development and Sleep

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Christoph Lindemann ◽  
Joachim Ahlbeck ◽  
Sebastian H. Bitzenhofer ◽  
Ileana L. Hanganu-Opatz
Keyword(s):  
Synaptic Plasticity ◽  
Present Knowledge ◽  
Adult Brain ◽  
Future Research ◽  
Brain Areas ◽  
Functional Differences ◽  
Spindle Activity ◽  
Early Brain Development ◽  
Underlying Mechanisms ◽  
And Function

Spindle oscillations have been described during early brain development and in the adult brain. Besides similarities in temporal patterns and involved brain areas, neonatal spindle bursts (NSBs) and adult sleep spindles (ASSs) show differences in their occurrence, spatial distribution, and underlying mechanisms. While NSBs have been proposed to coordinate the refinement of the maturating neuronal network, ASSs are associated with the implementation of acquired information within existing networks. Along with these functional differences, separate synaptic plasticity mechanisms seem to be recruited. Here, we review the generation of spindle oscillations in the developing and adult brain and discuss possible implications of their differences for synaptic plasticity. The first part of the review is dedicated to the generation and function of ASSs with a particular focus on their role in healthy and impaired neuronal networks. The second part overviews the present knowledge of spindle activity during development and the ability of NSBs to organize immature circuits. Studies linking abnormal maturation of brain wiring with neurological and neuropsychiatric disorders highlight the importance to better elucidate neonatal plasticity rules in future research.

scholarly journals Modulation of Synaptic Plasticity by Glutamatergic Gliotransmission: A Modeling Study

2016 ◽  
Vol 2016 ◽  
pp. 1-30 ◽  
Author(s):  
Maurizio De Pittà ◽  
Nicolas Brunel
Keyword(s):  
Synaptic Plasticity ◽  
Glutamate Release ◽  
Spike Timing ◽  
Biophysical Model ◽  
Dependent Manner ◽  
Inward Currents ◽  
Functional Relevance ◽  
And Function ◽  
Activity Dependent

Glutamatergic gliotransmission, that is, the release of glutamate from perisynaptic astrocyte processes in an activity-dependent manner, has emerged as a potentially crucial signaling pathway for regulation of synaptic plasticity, yet its modes of expression and function in vivo remain unclear. Here, we focus on two experimentally well-identified gliotransmitter pathways, (i) modulations of synaptic release and (ii) postsynaptic slow inward currents mediated by glutamate released from astrocytes, and investigate their possible functional relevance on synaptic plasticity in a biophysical model of an astrocyte-regulated synapse. Our model predicts that both pathways could profoundly affect both short- and long-term plasticity. In particular, activity-dependent glutamate release from astrocytes could dramatically change spike-timing-dependent plasticity, turning potentiation into depression (and vice versa) for the same induction protocol.

scholarly journals Role of MicroRNA in Governing Synaptic Plasticity

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Yuqin Ye ◽  
Hongyu Xu ◽  
Xinhong Su ◽  
Xiaosheng He
Keyword(s):  
Synaptic Plasticity ◽  
Neurological Disorders ◽  
Therapeutic Strategy ◽  
Target Gene ◽  
Synaptic Function ◽  
The Novel ◽  
Individual Mirnas ◽  
Underlying Mechanisms ◽  
And Function

Although synaptic plasticity in neural circuits is orchestrated by an ocean of genes, molecules, and proteins, the underlying mechanisms remain poorly understood. Recently, it is well acknowledged that miRNA exerts widespread regulation over the translation and degradation of target gene in nervous system. Increasing evidence suggests that quite a few specific miRNAs play important roles in various respects of synaptic plasticity including synaptogenesis, synaptic morphology alteration, and synaptic function modification. More importantly, the miRNA-mediated regulation of synaptic plasticity is not only responsible for synapse development and function but also involved in the pathophysiology of plasticity-related diseases. A review is made here on the function of miRNAs in governing synaptic plasticity, emphasizing the emerging regulatory role of individual miRNAs in synaptic morphological and functional plasticity, as well as their implications in neurological disorders. Understanding of the way in which miRNAs contribute to synaptic plasticity provides rational clues in establishing the novel therapeutic strategy for plasticity-related diseases.

scholarly journals A comparison of three different methods of eliciting rapid activity-dependent synaptic plasticity at the Drosophila NMJ

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260553
Author(s):  
Carolina Maldonado-Díaz ◽  
Mariam Vazquez ◽  
Bruno Marie
Keyword(s):  
Synaptic Plasticity ◽  
Red Light ◽  
Membrane Resistance ◽  
Resting Potential ◽  
Electrophysiological Properties ◽  
Electrophysiological Studies ◽  
Rich Solution ◽  
And Function ◽  
Synaptic Structures ◽  
Activity Dependent

The Drosophila NMJ is a system of choice for investigating the mechanisms underlying the structural and functional modifications evoked during activity-dependent synaptic plasticity. Because fly genetics allows considerable versatility, many strategies can be employed to elicit this activity. Here, we compare three different stimulation methods for eliciting activity-dependent changes in structure and function at the Drosophila NMJ. We find that the method using patterned stimulations driven by a K+-rich solution creates robust structural modifications but reduces muscle viability, as assessed by resting potential and membrane resistance. We argue that, using this method, electrophysiological studies that consider the frequency of events, rather than their amplitude, are the only reliable studies. We contrast these results with the expression of CsChrimson channels and red-light stimulation at the NMJ, as well as with the expression of TRPA channels and temperature stimulation. With both these methods we observed reliable modifications of synaptic structures and consistent changes in electrophysiological properties. Indeed, we observed a rapid appearance of immature boutons that lack postsynaptic differentiation, and a potentiation of spontaneous neurotransmission frequency. Surprisingly, a patterned application of temperature changes alone is sufficient to provoke both structural and functional plasticity. In this context, temperature-dependent TRPA channel activation induces additional structural plasticity but no further increase in the frequency of spontaneous neurotransmission, suggesting an uncoupling of these mechanisms.

scholarly journals Synaptic plasticity induced by differential manipulation of tonic and phasic motoneurons in Drosophila

2020 ◽  
Author(s):  
Nicole A. Aponte-Santiago ◽  
Kiel G. Ormerod ◽  
Yulia Akbergenova ◽  
J. Troy Littleton
Keyword(s):  
Synaptic Plasticity ◽  
Structural Changes ◽  
Neuromuscular Junctions ◽  
Target Display ◽  
Nervous Systems ◽  
Genetic Manipulations ◽  
Muscle Innervation ◽  
Synaptic Boutons ◽  
Underlying Mechanisms ◽  
And Function

AbstractStructural and functional plasticity induced by neuronal competition is a common feature of developing nervous systems. However, the rules governing how postsynaptic cells differentiate between presynaptic inputs are unclear. In this study we characterized synaptic interactions following manipulations of Ib tonic or Is phasic glutamatergic motoneurons that co-innervate postsynaptic muscles at Drosophila neuromuscular junctions (NMJs). After identifying drivers for each neuronal subtype, we performed ablation or genetic manipulations to alter neuronal activity and examined the effects on synaptic innervation and function. Ablation of either Ib or Is resulted in decreased muscle response, with some functional compensation occurring in the tonic Ib input when Is was missing. In contrast, the phasic Is terminal failed to show functional or structural changes following loss of the co-innervating Ib input. Decreasing the activity of the Ib or Is neuron with tetanus toxin light chain resulted in structural changes in muscle innervation. Decreased Ib activity resulted in reduced active zone (AZ) number and decreased postsynaptic subsynaptic reticulum (SSR) volume, with the emergence of filopodial-like protrusions from synaptic boutons of the Ib input. Decreased Is activity did not induce structural changes at its own synapses, but the co-innervating Ib motoneuron increased the number of synaptic boutons and AZs it formed. These findings indicate tonic and phasic neurons respond independently to changes in activity, with either functional or structural alterations in the tonic motoneuron occurring following ablation or reduced activity of the co-innervating phasic input, respectively.Significance StatementBoth invertebrate and vertebrate nervous systems display synaptic plasticity in response to behavioral experiences, indicating underlying mechanisms emerged early in evolution. How specific neuronal classes innervating the same postsynaptic target display distinct types of plasticity is unclear. Here, we examined if Drosophila tonic Ib and phasic Is motoneurons display competitive or cooperative interactions during innervation of the same muscle, or compensatory changes when the output of one motoneuron is altered. We established a system to differentially manipulate the motoneurons and examined the effects of cell-type specific changes to one of the inputs. Our findings indicate Ib and Is motoneurons respond differently to activity mismatch or loss of the co-innervating input, with the tonic subclass responding robustly compared to phasic motoneurons.

Spatial Organisation in Small Flocks of Domestic Fowl

Behaviour ◽  
1968 ◽  
Vol 32 (4) ◽  
pp. 258-290 ◽  
Author(s):  
Alan Lill
Keyword(s):  
Aggressive Behaviour ◽  
Domestic Fowl ◽  
Sexual Difference ◽  
Agonistic Interaction ◽  
Spatial Organisation ◽  
Individual Distance ◽  
Specific Activities ◽  
Underlying Mechanisms ◽  
And Function ◽  
Activity Dependent

Abstract(i) Spatial organisation was studied in small flocks of domestic fowl to elucidate its underlying mechanisms and provide a basis for future comparative analyses. (ii) Approach-tolerance distance values were obtained in a non-competitive feeding and a roosting situation. (iii) A zone of variable width across which the likelihood of approach eliciting agonistic response increased centripetally was observed around feeding birds. No sexual difference in zone width was noted, and tolerance of approach was great. (iv) No indication of constant Individual Distance in roosting birds was obtained, though spatial adjustment following agonistic interaction was observed. Clumping was common. (v) Activity-dependent variability in spatial organisation was described and correlated with the distribution of aggressive behaviour. (vi) It was postulated that the state of dispersion during specific activities was explicable in terms of the interaction of the opposed tendencies to congregate and aggregate and to react aggressively when approached. (vii) The nature and distribution of clumping and allopreening responses were described, and their causation and function discussed.

scholarly journals Intranasal insulin rescues repeated anesthesia-induced deficits in synaptic plasticity and memory and prevents apoptosis in neonatal mice via mTORC1

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Patricia Soriano Roque ◽  
Mehdi Hooshmandi ◽  
Laura Neagu-Lund ◽  
Shelly Yin ◽  
Noosha Yousefpour ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Synaptic Plasticity ◽  
General Anesthesia ◽  
Preventive Treatment ◽  
Intranasal Insulin ◽  
Translational Repressor ◽  
Beneficial Effects ◽  
Underlying Mechanisms ◽  
Induced Apoptosis ◽  
Preclinical And Clinical Studies

AbstractLong-lasting cognitive impairment in juveniles undergoing repeated general anesthesia has been observed in numerous preclinical and clinical studies, yet, the underlying mechanisms remain unknown and no preventive treatment is available. We found that daily intranasal insulin administration to juvenile mice for 7 days prior to repeated isoflurane anesthesia rescues deficits in hippocampus-dependent memory and synaptic plasticity in adulthood. Moreover, intranasal insulin prevented anesthesia-induced apoptosis of hippocampal cells, which is thought to underlie cognitive impairment. Inhibition of the mechanistic target of rapamycin complex 1 (mTORC1), a major intracellular effector of insulin receptor, blocked the beneficial effects of intranasal insulin on anesthesia-induced apoptosis. Consistent with this finding, mice lacking mTORC1 downstream translational repressor 4E-BP2 showed no induction of repeated anesthesia-induced apoptosis. Our study demonstrates that intranasal insulin prevents general anesthesia-induced apoptosis of hippocampal cells, and deficits in synaptic plasticity and memory, and suggests that the rescue effect is mediated via mTORC1/4E-BP2 signaling.

scholarly journals Targeting Pin1 for Modulation of Cell Motility and Cancer Therapy

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 359
Author(s):  
Hsiang-Hao Chuang ◽  
Yen-Yi Zhen ◽  
Yu-Chen Tsai ◽  
Cheng-Hao Chuang ◽  
Ming-Shyan Huang ◽  
...  
Keyword(s):  
Cancer Therapy ◽  
Tumor Suppressors ◽  
Protein Conformation ◽  
Genome Stability ◽  
Recent Progress ◽  
Multiple Roles ◽  
Cancer Development ◽  
Cancer Hallmarks ◽  
Underlying Mechanisms ◽  
And Function

Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) specifically binds and isomerizes the phosphorylated serine/threonine-proline (pSer/Thr-Pro) motif, which leads to changes in protein conformation and function. Pin1 is widely overexpressed in cancers and plays an important role in tumorigenesis. Mounting evidence has revealed that targeting Pin1 is a potential therapeutic approach for various cancers by inhibiting cell proliferation, reducing metastasis, and maintaining genome stability. In this review, we summarize the underlying mechanisms of Pin1-mediated upregulation of oncogenes and downregulation of tumor suppressors in cancer development. Furthermore, we also discuss the multiple roles of Pin1 in cancer hallmarks and examine Pin1 as a desirable pharmaceutical target for cancer therapy. We also summarize the recent progress of Pin1-targeted small-molecule compounds for anticancer activity.

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