Impaired neurotransmission caused by overexpression of α-synuclein in nigral dopamine neurons.
Lundblad, Martin LU ; Decressac, Mickael LU ; Mattsson, Bengt LU and Björklund, Anders LU
(2012)
In Proceedings of the National Academy of Sciences
109(9).
p.3213-3219
- Abstract
- We used in vivo amperometry to monitor changes in synaptic dopamine (DA) release in the striatum induced by overexpression of human wild-type α-synuclein in nigral DA neurons, induced by injection of an adeno-associated virus type 6 (AAV6)-α-synuclein vector unilaterally into the substantia nigra in adult rats. Impairments in DA release evolved in parallel with the development of degenerative changes in the nigrostriatal axons and terminals. The earliest change, seen 10 d after vector injection, was a marked, ≈50%, reduction in DA reuptake, consistent with an early dysfunction of the DA transporter that developed before any overt signs of axonal damage. At 3 wk, when the first signs of axonal damage were observed, the amount of DA released... (More)
- We used in vivo amperometry to monitor changes in synaptic dopamine (DA) release in the striatum induced by overexpression of human wild-type α-synuclein in nigral DA neurons, induced by injection of an adeno-associated virus type 6 (AAV6)-α-synuclein vector unilaterally into the substantia nigra in adult rats. Impairments in DA release evolved in parallel with the development of degenerative changes in the nigrostriatal axons and terminals. The earliest change, seen 10 d after vector injection, was a marked, ≈50%, reduction in DA reuptake, consistent with an early dysfunction of the DA transporter that developed before any overt signs of axonal damage. At 3 wk, when the first signs of axonal damage were observed, the amount of DA released after a KCl pulse was reduced by 70-80%, and peak DA concentration was delayed, indicating an impaired release mechanism. At later time points, 8-16 wk, overall striatal innervation density was reduced by 60-80% and accompanied by abundant signs of axonal damage in the form of α-synuclein aggregates, axonal swellings, and dystrophic axonal profiles. At this stage DA release and reuptake were profoundly reduced, by 80-90%. The early changes in synaptic DA release induced by overexpression of human α-synuclein support the idea that early predegenerative changes in the handling of DA may initiate, and drive, a progressive degenerative process that hits the axons and terminals first. Synaptic dysfunction and axonopathy would thus be the hallmark of presymptomatic and early-stage Parkinson disease, followed by neuronal degeneration and cell loss, characteristic of more advanced stages of the disease. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/2367155
- author
- Lundblad, Martin
LU
; Decressac, Mickael
LU
; Mattsson, Bengt
LU
and Björklund, Anders
LU
- organization
- publishing date
- 2012
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- synaptic transmission, neurodegeneration
- in
- Proceedings of the National Academy of Sciences
- volume
- 109
- issue
- 9
- pages
- 3213 - 3219
- publisher
- National Academy of Sciences
- external identifiers
-
- wos:000300828200013
- pmid:22315428
- scopus:84857716290
- ISSN
- 1091-6490
- DOI
- 10.1073/pnas.1200575109
- language
- English
- LU publication?
- yes
- id
- 57127f6b-91b5-4e22-b085-0d74d934d250 (old id 2367155)
- alternative location
- http://www.ncbi.nlm.nih.gov/pubmed/22315428?dopt=Abstract
- date added to LUP
- 2016-04-01 11:14:13
- date last changed
- 2022-05-18 17:16:03
@article{57127f6b-91b5-4e22-b085-0d74d934d250,
abstract = {{We used in vivo amperometry to monitor changes in synaptic dopamine (DA) release in the striatum induced by overexpression of human wild-type α-synuclein in nigral DA neurons, induced by injection of an adeno-associated virus type 6 (AAV6)-α-synuclein vector unilaterally into the substantia nigra in adult rats. Impairments in DA release evolved in parallel with the development of degenerative changes in the nigrostriatal axons and terminals. The earliest change, seen 10 d after vector injection, was a marked, ≈50%, reduction in DA reuptake, consistent with an early dysfunction of the DA transporter that developed before any overt signs of axonal damage. At 3 wk, when the first signs of axonal damage were observed, the amount of DA released after a KCl pulse was reduced by 70-80%, and peak DA concentration was delayed, indicating an impaired release mechanism. At later time points, 8-16 wk, overall striatal innervation density was reduced by 60-80% and accompanied by abundant signs of axonal damage in the form of α-synuclein aggregates, axonal swellings, and dystrophic axonal profiles. At this stage DA release and reuptake were profoundly reduced, by 80-90%. The early changes in synaptic DA release induced by overexpression of human α-synuclein support the idea that early predegenerative changes in the handling of DA may initiate, and drive, a progressive degenerative process that hits the axons and terminals first. Synaptic dysfunction and axonopathy would thus be the hallmark of presymptomatic and early-stage Parkinson disease, followed by neuronal degeneration and cell loss, characteristic of more advanced stages of the disease.}},
author = {{Lundblad, Martin and Decressac, Mickael and Mattsson, Bengt and Björklund, Anders}},
issn = {{1091-6490}},
keywords = {{synaptic transmission; neurodegeneration}},
language = {{eng}},
number = {{9}},
pages = {{3213--3219}},
publisher = {{National Academy of Sciences}},
series = {{Proceedings of the National Academy of Sciences}},
title = {{Impaired neurotransmission caused by overexpression of α-synuclein in nigral dopamine neurons.}},
url = {{http://dx.doi.org/10.1073/pnas.1200575109}},
doi = {{10.1073/pnas.1200575109}},
volume = {{109}},
year = {{2012}},
}