The Role of Extracellular Adenosine in Regulating Mossy Fiber Synaptic Plasticity
Reads0
Chats0
TLDR
A reduction of the basal release probability by ambient adenosine does not underlie presynaptic forms of plasticity at mossy fiber synapses in mouse and rat hippocampal slices.Abstract:
Hippocampal mossy fiber synapses show unique molecular features and dynamic range of plasticity. A recent paper proposed that the defining features of mossy fiber synaptic plasticity are caused by a local buildup of extracellular adenosine ([Moore et al., 2003][1]). In this study, we reassessed the role of ambient adenosine in regulating mossy fiber synaptic plasticity in mouse and rat hippocampal slices. Synaptic transmission was highly sensitive to activation of presynaptic adenosine A1 receptors (A1Rs), which reduced transmitter release by >75%. However, most of A1Rs were not activated by ambient adenosine. Field potentials increased only by 20-30% when A1Rs were fully blocked with the A1R antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) (1 μm). Moreover, blocking A1Rs hardly altered paired-pulse facilitation, frequency facilitation, or posttetanic potentiation. Frequency facilitation was similar in A1R -/- mice and when measured with NMDA receptor-mediated EPSCs in CA3 pyramidal cells in the presence of DPCPX. Additional experiments suggested that the results obtained by Moore et al. ([2003][1]) can partially be explained by their usage of a submerged recording chamber and elevated divalent cation concentrations. In conclusion, a reduction of the basal release probability by ambient adenosine does not underlie presynaptic forms of plasticity at mossy fiber synapses.
[1]: #ref-23read more
Citations
More filters
Journal ArticleDOI
Physiology and Pathophysiology of Purinergic Neurotransmission
TL;DR: This review is focused on purinergic neurotransmission, i.e., ATP released from nerves as a transmitter or cotransmitter to act as an extracellular signaling molecule on both pre- and postjunctional membranes at neuroeffector junctions and synapses, as well as acting as a trophic factor during development and regeneration.
Journal ArticleDOI
Astrocytic purinergic signaling coordinates synaptic networks.
Olivier Pascual,Kristen B. Casper,Cathryn Kubera,Jing Zhang,Raquel Revilla-Sanchez,Jai Yoon Sul,Hajime Takano,Stephen J. Moss,Ken D. McCarthy,Philip G. Haydon +9 more
TL;DR: The results indicate that astrocytes are intricately linked in the regulation of synaptic strength and plasticity and provide a pathway for synaptic cross-talk.
Journal ArticleDOI
Purinergic signalling in neuron–glia interactions
TL;DR: The involvement of ATP and adenosine receptors in neuron–glia signalling, including the release and hydrolysis of ATP, how the receptors signal, the pharmacological tools used to study them, and their functional significance are reviewed.
Journal ArticleDOI
Synaptic plasticity at hippocampal mossy fibre synapses
Roger A. Nicoll,Dietmar Schmitz +1 more
TL;DR: Recent work from several laboratories on the various forms of synaptic plasticity at hippocampal mossy fibre synapses conclude that these contacts have just begun to reveal their many secrets.
Journal ArticleDOI
Adenosine A2A receptors are essential for long-term potentiation of NMDA-EPSCs at hippocampal mossy fiber synapses.
TL;DR: It is shown that A2A receptors are localized postsynaptically at synapses between mossy fibers and CA3 pyramidal cells and are essential for a form of long-term potentiation of NMDA-EPSCs induced by short bursts of mossy fiber stimulation.
References
More filters
Journal ArticleDOI
Short-Term Synaptic Plasticity
Robert S. Zucker,Wade G. Regehr +1 more
TL;DR: The evidence for this hypothesis, and the origins of the different kinetic phases of synaptic enhancement, as well as the interpretation of statistical changes in transmitter release and roles played by other factors such as alterations in presynaptic Ca(2+) influx or postsynaptic levels of [Ca(2+)]i are discussed.
Journal ArticleDOI
The Role and Regulation of Adenosine in the Central Nervous System
TL;DR: A role for adenosine in a diverse array of neural phenomena, which include regulation of sleep and the level of arousal, neuroprotection, regulation of seizure susceptibility, locomotor effects, analgesia, mediation of the effects of ethanol, and chronic drug use, is established.
Journal ArticleDOI
Adenosine in the central nervous system: release mechanisms and extracellular concentrations.
Serena Latini,Felicita Pedata +1 more
TL;DR: Key characteristics of adenosine release in the brain in response to different stimuli will be summarized, and studies performed to evaluateadenosine concentrations under physiological and hypoxic/ischemic conditions will be described to evaluate the degree of adenoine receptor activation.
Journal ArticleDOI
Dynamic Control of Presynaptic Ca2+ Inflow by Fast-Inactivating K+ Channels in Hippocampal Mossy Fiber Boutons
Jörg R. P. Geiger,Peter Jonas +1 more
TL;DR: Patch-clamp recordings from mossy fiber boutons (MFBs) in rat hippocampal slices show that inactivation of presynaptic K(+) channels contributes to the control of efficacy of a glutamatergic synapse in the cortex.