FAD-Linked Autofluorescence and Chemically-Evoked Zinc Changes at Hippocampal Mossy Fiber-CA3 Synapses
(2021)- Abstract
- Glutamatergic vesicles in hippocampal mossy fiber presynaptic boutons release zinc, which plays a modulatory role in synaptic activity and LTP. In this work, a fluorescence microscopy technique and the fluorescent probe for cytosolic zinc, Newport Green (NG), were applied, in a combined study of autofluorescence and zinc changes at the hippocampal mossy fiber-CA3 synaptic system. In particular, the dynamics of flavoprotein (FAD) autofluorescence signals, was compared to that of postsynaptic zinc signals, elicited both by high K+ (20 mM) and by tetraethylammonium (TEA, 25 mM). The real zinc signals were obtained subtracting autofluorescence values, from corresponding total NG-fluorescence data. Both autofluorescence and zinc-related... (More)
- Glutamatergic vesicles in hippocampal mossy fiber presynaptic boutons release zinc, which plays a modulatory role in synaptic activity and LTP. In this work, a fluorescence microscopy technique and the fluorescent probe for cytosolic zinc, Newport Green (NG), were applied, in a combined study of autofluorescence and zinc changes at the hippocampal mossy fiber-CA3 synaptic system. In particular, the dynamics of flavoprotein (FAD) autofluorescence signals, was compared to that of postsynaptic zinc signals, elicited both by high K+ (20 mM) and by tetraethylammonium (TEA, 25 mM). The real zinc signals were obtained subtracting autofluorescence values, from corresponding total NG-fluorescence data. Both autofluorescence and zinc-related fluorescence were raised by high K+. In contrast, the same signals were reduced during TEA exposure. It is suggested that the initial outburst of TEA-evoked zinc release might activate ATP-sensitive K+ (KATP) channels, as part of a safeguard mechanism against excessive glutamatergic action. This would cause sustained inhibition of zinc signals and a more reduced mitochondrial state. In favor of the “KATP channel hypothesis”, the KATP channel blocker tolbutamide (250 μM) nearly suppressed the TEA-evoked fluorescence changes. It is concluded that recording autofluorescence from brain slices is essential for the accurate assessment of zinc signals and actions. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/f573775e-5c82-4c28-b737-01f3d0ab8997
- author
- Bastos, Fatima M.C. ; Matias, Carlos M. ; Lopes, Ines O. ; Vieira, João P. LU ; Santos, Rosa M. ; Rosario, Luis M. ; Quinta-Ferreira, Rosa M. and Quinta-Ferreira, Maria Emília
- publishing date
- 2021-11-03
- type
- Chapter in Book/Report/Conference proceeding
- publication status
- published
- subject
- host publication
- Hippocampus - New Advances [Working Title]
- editor
- Zhang, Prof. Xinhua
- publisher
- IntechOpen
- DOI
- 10.5772/intechopen.100898
- language
- English
- LU publication?
- no
- id
- f573775e-5c82-4c28-b737-01f3d0ab8997
- date added to LUP
- 2021-11-09 10:22:48
- date last changed
- 2021-11-15 13:08:29
@inbook{f573775e-5c82-4c28-b737-01f3d0ab8997, abstract = {{Glutamatergic vesicles in hippocampal mossy fiber presynaptic boutons release zinc, which plays a modulatory role in synaptic activity and LTP. In this work, a fluorescence microscopy technique and the fluorescent probe for cytosolic zinc, Newport Green (NG), were applied, in a combined study of autofluorescence and zinc changes at the hippocampal mossy fiber-CA3 synaptic system. In particular, the dynamics of flavoprotein (FAD) autofluorescence signals, was compared to that of postsynaptic zinc signals, elicited both by high K+ (20 mM) and by tetraethylammonium (TEA, 25 mM). The real zinc signals were obtained subtracting autofluorescence values, from corresponding total NG-fluorescence data. Both autofluorescence and zinc-related fluorescence were raised by high K+. In contrast, the same signals were reduced during TEA exposure. It is suggested that the initial outburst of TEA-evoked zinc release might activate ATP-sensitive K+ (KATP) channels, as part of a safeguard mechanism against excessive glutamatergic action. This would cause sustained inhibition of zinc signals and a more reduced mitochondrial state. In favor of the “KATP channel hypothesis”, the KATP channel blocker tolbutamide (250 μM) nearly suppressed the TEA-evoked fluorescence changes. It is concluded that recording autofluorescence from brain slices is essential for the accurate assessment of zinc signals and actions.}}, author = {{Bastos, Fatima M.C. and Matias, Carlos M. and Lopes, Ines O. and Vieira, João P. and Santos, Rosa M. and Rosario, Luis M. and Quinta-Ferreira, Rosa M. and Quinta-Ferreira, Maria Emília}}, booktitle = {{Hippocampus - New Advances [Working Title]}}, editor = {{Zhang, Prof. Xinhua}}, language = {{eng}}, month = {{11}}, publisher = {{IntechOpen}}, title = {{FAD-Linked Autofluorescence and Chemically-Evoked Zinc Changes at Hippocampal Mossy Fiber-CA3 Synapses}}, url = {{http://dx.doi.org/10.5772/intechopen.100898}}, doi = {{10.5772/intechopen.100898}}, year = {{2021}}, }