The regulation and packaging of synaptic vesicles as related to recruitment within glutamatergic synapses

Cooper, Robin L.

doi:10.1016/j.neuroscience.2012.08.037

Cited by 15 publications

(10 citation statements)

References 75 publications

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“…The amplitude of the 25th EJPs within the response train was used as an index for the effects of LPS and 5-HT ( Figure 1). The rationale for using 25th pulses in a train is that, by the 25th pulse, a plateau in the amplitude of the EJP is usually reached at room temperature for the opener NMJs [42].…”

Section: Resultsmentioning

confidence: 99%

“…Since the opener NMJ preparation is physiologically stable for hours with relatively low frequency stimulation or short stimulus trains with prolonged intervals of rest, there was little depression in synaptic efficacy [9,[42][43][44]. Also, the effects of LPS exposure over prolonged periods of time were previously addressed in this preparation [26].…”

Section: Discussionmentioning

confidence: 99%

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The Effect of Bacterial Endotoxin LPS on Serotonergic Modulation of Glutamatergic Synaptic Transmission

Bernard

Greenhalgh

Istas

et al. 2020

Biology

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The release of the endotoxin lipopolysaccharides (LPS) from gram-negative bacteria is key in the induction of the downstream cytokine release from cells targeting cells throughout the body. However, LPS itself has direct effects on cellular activity and can alter synaptic transmission. Animals experiencing septicemia are generally in a critical state and are often treated with various pharmacological agents. Since antidepressants related to the serotonergic system have been shown to have a positive outcome for septicemic conditions impacting the central nervous system, the actions of serotonin (5-HT) on neurons also exposed to LPS were investigated. At the model glutamatergic synapse of the crayfish neuromuscular junction (NMJ), 5-HT primarily acts through a 5-HT2A receptor subtype to enhance transmission to the motor neurons. LPS from Serratia marcescens also enhances transmission at the crayfish NMJ but by a currently unknown mechanism. LPS at 100 µg/mL had no significant effect on transmission or on altering the response to 5-HT. LPS at 500 µg/mL increased the amplitude of the evoked synaptic excitatory junction potential, and 5-HT in combination with 500 µg/mL LPS continued to promote enhanced transmission. The preparations maintained responsiveness to serotonin in the presence of low or high concentrations of LPS.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

The Effect of Bacterial Endotoxin LPS on Serotonergic Modulation of Glutamatergic Synaptic Transmission

Bernard

Greenhalgh

Istas

et al. 2020

Biology

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“…After an initial increase in Ca 2+ ‐dependent neurotransmitter release, inhibition of Ca 2+ /H + antiport results in fading of transmission, particularly when synapses are stimulated repetitively (Cordeiro et al . ; Wu and Cooper ), an effect probably involving desensitization of the release mechanism through mediatophores, consecutive to steady increase in sub‐threshold [Ca 2+ ] i (Adams et al . ; Israël et al .…”

Section: Discussionmentioning

confidence: 99%

Synaptotagmin 1 is required for vesicular Ca²⁺/H⁺‐antiport activity

Cordeiro

Boda

Gonçalves

et al. 2013

Journal of Neurochemistry

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A low-affinity Ca 2+ /H + -antiport was described in the membrane of mammalian brain synaptic vesicles. Electrophysiological studies showed that this antiport contributes to the extreme brevity of excitation-release coupling in rapid synapses. Synaptotagmin-1, a vesicular protein interacting with membranes upon low-affinity Ca 2+ -binding, plays a major role in excitation-release coupling, by synchronizing calcium entry with fast neurotransmitter release. Here, we report that synaptotagmin-1 is necessary for expression of the vesicular Ca /H + -antiport activity is detectable only in acidic organelles expressing functional synaptotagmin-1. In contrast, synaptotagmin-1-deficient cells -and cells where transgenically encoded synaptotagmin-1 was acutely photo-inactivated -were devoid of any Ca 2+ /H + -antiport activity. Therefore, in addition to its previously described functions, synaptotagmin-1 is involved in a rapid vesicular Ca 2+ sequestration through a Ca It has long been known that synaptic vesicles and other secretory granules take up Ca 2+ by ATP-dependent mechanisms (Isra€ el et al. 1980;Michaelson et al. 1980;Parekh 2008). Two distinct mechanisms contribute to transport calcium into vesicles: a high-affinity Ca 2+ -ATPase pump, and a low-affinity Ca 2+ /H + -antiport, which was extensively investigated using synaptic vesicles isolated from mammalian brain cortex. The vesicular Ca 2+ /H + -antiport is activated only at high Ca 2+ concentrations (K 0.5 = 217 lM; maximum velocity at~500-600 lM). Its activity depends on the DpH across the vesicle membrane, and therefore on the vacuolar H + -transporting ATPase (V-ATPase) (Gonc ßalves et al. 1998(Gonc ßalves et al. , 1999b(Gonc ßalves et al. , 2000.It is expected that the high-affinity Ca 2+ -pumps transport Ca 2+ ions into vesicles (and into other organelles) when the synapse is in resting state, keeping the cytosolic Ca 2+ concentration ([Ca 2+ ] i ) at the very low physiological level. As for the Ca 2+ /H + -antiport, it would operate only at brief instants following a presynaptic action potential, when [Ca 2+ ] i abruptly raises to sub-millimolar levels in discrete spots (nano-domains) close to the inner mouth of voltage-operated calcium channels (VOCCs) (Llinas et al. 1992 Searching for a molecular counterpart of the vesicular Ca 2+ /H + -antiport activity, we suspected that synaptotagmins might be involved. Synaptotagmins form a family of proteins associated with synaptic vesicles. Synaptotagmin-1 (SYT-1) has a conserved N-terminal inside the vesicle and two C2 domains facing the cytosol, which are able to bind Ca 2+ with low affinity (60 lM to 600 lM) (Takamori et al. 2006;Chapman 2008). SYT-1 also binds in a dynamic and Ca 2+ -dependent manner to the hetero-trimeric protein complex SNARE (VAMP/synaptobrevin + SNAP-25+ syntaxin), to other proteins (complexin, etc.), to VOCCs and to phospholipids. SYT-1 and the above proteins form between vesicles and the plasma membrane a multimolecular complex, which is important for efficient excitation-...

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“…Serotonin (5-HT) has been associated with aggressive behavior [88,[130][131][132][133]. In invertebrates, increased serotonin shows an increase in aggression [134] since infusion of 5-HT in the hemocoel cavity of the crayfish Astacus astacus caused the animal to fight longer in an encounter [6,135]. It is most likely that after aggressive interactions, further physiological changes are associated with energy metabolism in modifying the neuroendocrine system due to energy depletion and hormonal actions which may even alter synaptic communication [135,136].…”

Section: Discussionmentioning

confidence: 99%

Sensory Systems and Environmental Change on Behavior during Social Interactions

Bierbower

Nadolski

Cooper

2013

International Journal of Zoology

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The impact of environmental conditions for transmitting sensory cues and the ability of crayfish to utilize olfaction and vision were examined in regards to social interactive behavior. The duration and intensity of interactions were examined for conspecific crayfish with different sensory abilities. Normally, vision and chemosensory have roles in agonistic communication ofProcambarus clarkii; however, for the blind cave crayfish (Orconectes australis packardi), that lack visual capabilities, olfaction is assumed to be the primary sensory modality. To test this, we paired conspecifics in water and out of water in the presence and absence of white light to examine interactive behaviors when these various sensory modalities are altered. For sighted crayfish, in white light, interactions occurred and escalated; however, when the water was removed, interactions and aggressiveness decreased, but, there was an increase in visual displays out of the water. The loss of olfaction abilities for blind cave and sighted crayfish produced fewer social interactions. The importance of environmental conditions is illustrated for social interactions among sighted and blind crayfish. Importantly, this study shows the relevance in the ecological arena in nature for species survival and how environmental changes disrupt innate behaviors.

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The regulation and packaging of synaptic vesicles as related to recruitment within glutamatergic synapses

Cited by 15 publications

References 75 publications

The Effect of Bacterial Endotoxin LPS on Serotonergic Modulation of Glutamatergic Synaptic Transmission

The Effect of Bacterial Endotoxin LPS on Serotonergic Modulation of Glutamatergic Synaptic Transmission

Synaptotagmin 1 is required for vesicular Ca²⁺/H⁺‐antiport activity

Sensory Systems and Environmental Change on Behavior during Social Interactions

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The regulation and packaging of synaptic vesicles as related to recruitment within glutamatergic synapses

Cited by 15 publications

References 75 publications

The Effect of Bacterial Endotoxin LPS on Serotonergic Modulation of Glutamatergic Synaptic Transmission

The Effect of Bacterial Endotoxin LPS on Serotonergic Modulation of Glutamatergic Synaptic Transmission

Synaptotagmin 1 is required for vesicular Ca2+/H+‐antiport activity

Sensory Systems and Environmental Change on Behavior during Social Interactions

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Synaptotagmin 1 is required for vesicular Ca²⁺/H⁺‐antiport activity