Abstract
The Bergmann glia is equipped with Ca2+-permeable AMPA receptors for glutamate, indispensable for structural and functional relations between the Bergmann glia and parallel/climbing fibers-Purkinje cell synapses. To better understand roles for the Bergmann AMPA receptors, herein we investigate on gliotransmitter release and Ca2+ signals in isolated Bergmann glia processes obtained from adult rat cerebellum. We found that: 1) the rat cerebellar purified astrocyte processes (gliosomes) expressed astrocytic and Bergmann markers and exhibited negligible contamination by nerve terminals, microglia, or oligodendrocytes; 2) activation of Ca2+-permeable AMPA receptors caused Ca2+ signals in the processes, and the release of glutamate from the processes; 3) effectiveness of rose bengal, trypan blue or bafilomycin A1, indicated that activation of the AMPA receptors evoked vesicular glutamate release. Cerebellar purified nerve terminals appeared devoid of glutamate-releasing Ca2+-permeable AMPA receptors, indicating that neuronal contamination may not be the source of the signals detected. Ultrastructural analysis indicated the presence of vesicles in the cytoplasm of the processes; confocal imaging confirmed the presence of vesicular glutamate transporters in Bergmann glia processes. We conclude that: a vesicular mechanism for release of the gliotransmitter glutamate is present in mature Bergmann processes; entry of Ca2+ through the AMPA receptors located on Bergmann processes is coupled with vesicular glutamate release. The findings would add a new role for a well-known Bergmann target for glutamate (the Ca2+-permeable AMPA receptors) and a new actor (the gliotransmitter glutamate) at the cerebellar excitatory synapses onto Purkinje cells.
| Original language | English |
|---|---|
| Article number | 5957 |
| Pages (from-to) | 396-407 |
| Number of pages | 12 |
| Journal | Neuropharmacology |
| Volume | 99 |
| DOIs | |
| Publication status | Published - Dec 1 2015 |
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Keywords
- Cerebellum
- Gliosomes
- Gliotransmitter release
- GluA2-lacking AMPA receptor
- Neuroglia
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience
- Pharmacology
Cite this
Calcium-permeable AMPA receptors trigger vesicular glutamate release from Bergmann gliosomes. / Cervetto, Chiara; Frattaroli, Daniela; Venturini, Arianna; Passalacqua, Mario; Nobile, Mario; Alloisio, Susanna; Tacchetti, Carlo; Maura, Guido; Agnati, Luigi Francesco; Marcoli, Manuela.
In: Neuropharmacology, Vol. 99, 5957, 01.12.2015, p. 396-407.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Calcium-permeable AMPA receptors trigger vesicular glutamate release from Bergmann gliosomes
AU - Cervetto, Chiara
AU - Frattaroli, Daniela
AU - Venturini, Arianna
AU - Passalacqua, Mario
AU - Nobile, Mario
AU - Alloisio, Susanna
AU - Tacchetti, Carlo
AU - Maura, Guido
AU - Agnati, Luigi Francesco
AU - Marcoli, Manuela
PY - 2015/12/1
Y1 - 2015/12/1
N2 - The Bergmann glia is equipped with Ca2+-permeable AMPA receptors for glutamate, indispensable for structural and functional relations between the Bergmann glia and parallel/climbing fibers-Purkinje cell synapses. To better understand roles for the Bergmann AMPA receptors, herein we investigate on gliotransmitter release and Ca2+ signals in isolated Bergmann glia processes obtained from adult rat cerebellum. We found that: 1) the rat cerebellar purified astrocyte processes (gliosomes) expressed astrocytic and Bergmann markers and exhibited negligible contamination by nerve terminals, microglia, or oligodendrocytes; 2) activation of Ca2+-permeable AMPA receptors caused Ca2+ signals in the processes, and the release of glutamate from the processes; 3) effectiveness of rose bengal, trypan blue or bafilomycin A1, indicated that activation of the AMPA receptors evoked vesicular glutamate release. Cerebellar purified nerve terminals appeared devoid of glutamate-releasing Ca2+-permeable AMPA receptors, indicating that neuronal contamination may not be the source of the signals detected. Ultrastructural analysis indicated the presence of vesicles in the cytoplasm of the processes; confocal imaging confirmed the presence of vesicular glutamate transporters in Bergmann glia processes. We conclude that: a vesicular mechanism for release of the gliotransmitter glutamate is present in mature Bergmann processes; entry of Ca2+ through the AMPA receptors located on Bergmann processes is coupled with vesicular glutamate release. The findings would add a new role for a well-known Bergmann target for glutamate (the Ca2+-permeable AMPA receptors) and a new actor (the gliotransmitter glutamate) at the cerebellar excitatory synapses onto Purkinje cells.
AB - The Bergmann glia is equipped with Ca2+-permeable AMPA receptors for glutamate, indispensable for structural and functional relations between the Bergmann glia and parallel/climbing fibers-Purkinje cell synapses. To better understand roles for the Bergmann AMPA receptors, herein we investigate on gliotransmitter release and Ca2+ signals in isolated Bergmann glia processes obtained from adult rat cerebellum. We found that: 1) the rat cerebellar purified astrocyte processes (gliosomes) expressed astrocytic and Bergmann markers and exhibited negligible contamination by nerve terminals, microglia, or oligodendrocytes; 2) activation of Ca2+-permeable AMPA receptors caused Ca2+ signals in the processes, and the release of glutamate from the processes; 3) effectiveness of rose bengal, trypan blue or bafilomycin A1, indicated that activation of the AMPA receptors evoked vesicular glutamate release. Cerebellar purified nerve terminals appeared devoid of glutamate-releasing Ca2+-permeable AMPA receptors, indicating that neuronal contamination may not be the source of the signals detected. Ultrastructural analysis indicated the presence of vesicles in the cytoplasm of the processes; confocal imaging confirmed the presence of vesicular glutamate transporters in Bergmann glia processes. We conclude that: a vesicular mechanism for release of the gliotransmitter glutamate is present in mature Bergmann processes; entry of Ca2+ through the AMPA receptors located on Bergmann processes is coupled with vesicular glutamate release. The findings would add a new role for a well-known Bergmann target for glutamate (the Ca2+-permeable AMPA receptors) and a new actor (the gliotransmitter glutamate) at the cerebellar excitatory synapses onto Purkinje cells.
KW - Cerebellum
KW - Gliosomes
KW - Gliotransmitter release
KW - GluA2-lacking AMPA receptor
KW - Neuroglia
UR - http://www.scopus.com/inward/record.url?scp=84939802786&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84939802786&partnerID=8YFLogxK
U2 - 10.1016/j.neuropharm.2015.08.011
DO - 10.1016/j.neuropharm.2015.08.011
M3 - Article
VL - 99
SP - 396
EP - 407
JO - Neuropharmacology
JF - Neuropharmacology
SN - 0028-3908
M1 - 5957
ER -