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 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 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 Borna Disease Virus Infection Impairs Synaptic Plasticity

2007 ◽  
Vol 81 (16) ◽  
pp. 8833-8837 ◽  
Author(s):  
Romain Volmer ◽  
Christine M. A. Prat ◽  
Gwendal Le Masson ◽  
André Garenne ◽  
Daniel Gonzalez-Dunia
Keyword(s):  
Synaptic Plasticity ◽  
Disease Virus ◽  
Network Activity ◽  
Multielectrode Arrays ◽  
Neuronal Function ◽  
Borna Disease Virus ◽  
Electrophysiological Properties ◽  
Neuronal Network Activity ◽  
Activity Dependent ◽  
Borna Disease

ABSTRACT The mechanisms whereby Borna disease virus (BDV) can impair neuronal function and lead to neurobehavioral disease are not well understood. To analyze the electrophysiological properties of neurons infected with BDV, we used cultures of neurons grown on multielectrode arrays, allowing a real-time monitoring of the electrical activity across the network shaped by synaptic transmission. Although infection did not affect spontaneous neuronal activity, it selectively blocked activity-dependent enhancement of neuronal network activity, one form of synaptic plasticity thought to be important for learning and memory. These findings highlight the original mechanism of the neuronal dysfunction caused by noncytolytic infection with BDV.

scholarly journals Intrinsic physiological properties of the five types of mouse ganglion-cell photoreceptors

2013 ◽  
Vol 109 (7) ◽  
pp. 1876-1889 ◽  
Author(s):  
Caiping Hu ◽  
DiJon D. Hill ◽  
Kwoon Y. Wong
Keyword(s):  
Ganglion Cells ◽  
Membrane Resistance ◽  
The Other ◽  
Functional Roles ◽  
Electrophysiological Properties ◽  
Voltage Gated ◽  
Physiological Diversity ◽  
Physiological Properties ◽  
Comprehensive Survey ◽  
And Function

In the mammalian retina, some ganglion cells express the photopigment melanopsin and function as photoreceptors. Five morphological types of these intrinsically photosensitive retinal ganglion cells (ipRGCs), M1–M5, have been identified in mice. Whereas M1 specializes in non-image-forming visual functions and drives such behaviors as the pupillary light reflex and circadian photoentrainment, the other types appear to contribute to image-forming as well as non-image-forming vision. Recent work has begun to reveal physiological diversity among some of the ipRGC types, including differences in photosensitivity, firing rate, and membrane resistance. To gain further insights into these neurons' functional differences, we conducted a comprehensive survey of the electrophysiological properties of all five morphological types. Compared with the other types, M1 had the highest membrane resistance, longest membrane time constant, lowest spike frequencies, widest action potentials, most positive spike thresholds, smallest hyperpolarization-activated inwardly-rectifying current-induced “sagging” responses to hyperpolarizing currents, and the largest effects of voltage-gated K+ currents on membrane potentials. M4 and M5 were at the other end of the spectrum for most of these measures, while M2 and M3 tended to be in the middle of this spectrum. Additionally, M1 and M2 cells generated more diverse voltage-gated Ca2+ currents than M3–M5. In conclusion, M1 cells are significantly different from all other ipRGCs in most respects, possibly reflecting the unique physiological requirements of non-image-forming vision. Furthermore, the non-M1 ipRGCs are electrophysiologically heterogeneous, implicating these cells' diverse functional roles in both non-image-forming vision and pattern vision.

scholarly journals Ion Channels and Electrophysiological Properties of Astrocytes: Implications for Emergent Stimulation Technologies

2021 ◽  
Vol 15 ◽  
Author(s):  
Jessica McNeill ◽  
Christopher Rudyk ◽  
Michael E. Hildebrand ◽  
Natalina Salmaso
Keyword(s):  
Membrane Resistance ◽  
Synaptic Activity ◽  
Signaling Cascades ◽  
Ion Regulation ◽  
Electrophysiological Properties ◽  
Physiological Properties ◽  
Different Types ◽  
Voltage Dependent ◽  
Intracellular Ca ◽  
And Function

Astrocytes comprise a heterogeneous cell population characterized by distinct morphologies, protein expression and function. Unlike neurons, astrocytes do not generate action potentials, however, they are electrically dynamic cells with extensive electrophysiological heterogeneity and diversity. Astrocytes are hyperpolarized cells with low membrane resistance. They are heavily involved in the modulation of K+ and express an array of different voltage-dependent and voltage-independent channels to help with this ion regulation. In addition to these K+ channels, astrocytes also express several different types of Na+ channels; intracellular Na+ signaling in astrocytes has been linked to some of their functional properties. The physiological hallmark of astrocytes is their extensive intracellular Ca2+ signaling cascades, which vary at the regional, subregional, and cellular levels. In this review article, we highlight the physiological properties of astrocytes and the implications for their function and influence of network and synaptic activity. Furthermore, we discuss the implications of these differences in the context of optogenetic and DREADD experiments and consider whether these tools represent physiologically relevant techniques for the interrogation of astrocyte function.

scholarly journals Physiological changes throughout the ear due to age and noise - a longitudinal study

2021 ◽  
Author(s):  
Alix Blockley ◽  
Daisy Ogle ◽  
Charlie Woodrow ◽  
Fernando Montealegre-Zapata ◽  
Ben Warren
Keyword(s):  
Hearing Loss ◽  
Auditory Nerve ◽  
Noise Exposure ◽  
Schistocerca Gregaria ◽  
Membrane Resistance ◽  
Resting Potential ◽  
Auditory Neurons ◽  
Electrophysiological Properties ◽  
Age Related ◽  
Transduction Current

Biological and mechanical systems, whether by their overuse or their aging, will inevitably fail. Hearing provides a poignant example of this with noise-induced and age-related hearing loss. Hearing loss is not unique to humans, however, and is experienced by all animals in the face of wild and eclectic differences in ear morphology and operation. Here we exploited the high throughput and accessible tympanal ear of the desert locust, Schistocerca gregaria (mixed sex) to rigorously quantify changes in the auditory system due to noise exposure (3 kHz pure tone at 126 dB SPL) and age. We analysed tympanal dispalcements, morphology of the auditory Mullers organ and measured activity of the auditory nerve, the transduction current and electrophysiological properties of individual auditory receptors. We found that noise mildly and transiently changes tympanal displacements, decreases both the width of the auditory nerve and the transduction current recorded from individual auditory neurons. Whereas age, but not noise, decreases the number of auditory neurons and increases their resting potential. Multiple other properties of Mullers organ were unaffected by either age or noise including: the number of supporting cells in Mullers organ or the nerve, membrane resistance and capacitance of the auditory neurons. The sound-evoked activity of the auditory nerve decreased as a function of age and this decrease was exacerbated by noise, with the largest difference during the middle of their life span. This middle-aged deafness pattern of hearing loss mirrors that found for humans exposed to noise early in their life.

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.

Sign in / Sign up

Export Citation Format

Share Document