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GIRK2 Expression in Dopamine Neurons of the Substantia Nigra and Ventral Tegmental Area

Reyes, Stefanie; Fu, Yuhong; Double, Kay; Thompson, Lachlan; Kirik, Deniz LU ; Paxinos, George and Halliday, Glenda M. (2012) In Journal of Comparative Neurology 520(12). p.2591-2607
Abstract
G-protein-regulated inward-rectifier potassium channel 2 (GIRK2) is reported to be expressed only within certain dopamine neurons of the substantia nigra (SN), although very limited data are available in humans. We examined the localization of GIRK2 in the SN and adjacent ventral tegmental area (VTA) of humans and mice by using either neuromelanin pigment or immunolabeling with tyrosine hydroxylase (TH) or calbindin. GIRK2 immunoreactivity was found in nearly every human pigmented neuron or mouse TH-immunoreactive neuron in both the SN and VTA, although considerable variability in the intensity of GIRK2 staining was observed. The relative intensity of GIRK2 immunoreactivity in TH-immunoreactive neurons was determined; in both species... (More)
G-protein-regulated inward-rectifier potassium channel 2 (GIRK2) is reported to be expressed only within certain dopamine neurons of the substantia nigra (SN), although very limited data are available in humans. We examined the localization of GIRK2 in the SN and adjacent ventral tegmental area (VTA) of humans and mice by using either neuromelanin pigment or immunolabeling with tyrosine hydroxylase (TH) or calbindin. GIRK2 immunoreactivity was found in nearly every human pigmented neuron or mouse TH-immunoreactive neuron in both the SN and VTA, although considerable variability in the intensity of GIRK2 staining was observed. The relative intensity of GIRK2 immunoreactivity in TH-immunoreactive neurons was determined; in both species nearly all SN TH-immunoreactive neurons had strong GIRK2 immunoreactivity compared with only 50-60% of VTA neurons. Most paranigral VTA neurons also contained calbindin immunoreactivity, and approximately 25% of these and nearby VTA neurons also had strong GIRK2 immunoreactivity. These data show that high amounts of GIRK2 protein are found in most SN neurons as well as in a proportion of nearby VTA neurons. The single previous human study may have been compromised by the fixation method used and the postmortem delay of their controls, whereas other studies suggesting that GIRK2 is located only in limited neuronal groups within the SN have erroneously included VTA regions as part of the SN. In particular, the dorsal layer of dopamine neurons directly underneath the red nucleus is considered a VTA region in humans but is commonly considered the dorsal tier of the SN in laboratory species. J. Comp. Neurol. 520: 2591-2607, 2012. (C) 2012 Wiley Periodicals, Inc. (Less)
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author
organization
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type
Contribution to journal
publication status
published
subject
keywords
GIRK2, human, mouse, substantia nigra
in
Journal of Comparative Neurology
volume
520
issue
12
pages
2591 - 2607
publisher
John Wiley & Sons
external identifiers
  • wos:000306129400004
  • scopus:84862118786
ISSN
1096-9861
DOI
10.1002/cne.23051
language
English
LU publication?
yes
id
04296cc8-f9dc-41e5-b4f3-2d05943ed430 (old id 2994831)
date added to LUP
2012-09-03 07:17:45
date last changed
2017-10-01 03:05:43
@article{04296cc8-f9dc-41e5-b4f3-2d05943ed430,
  abstract     = {G-protein-regulated inward-rectifier potassium channel 2 (GIRK2) is reported to be expressed only within certain dopamine neurons of the substantia nigra (SN), although very limited data are available in humans. We examined the localization of GIRK2 in the SN and adjacent ventral tegmental area (VTA) of humans and mice by using either neuromelanin pigment or immunolabeling with tyrosine hydroxylase (TH) or calbindin. GIRK2 immunoreactivity was found in nearly every human pigmented neuron or mouse TH-immunoreactive neuron in both the SN and VTA, although considerable variability in the intensity of GIRK2 staining was observed. The relative intensity of GIRK2 immunoreactivity in TH-immunoreactive neurons was determined; in both species nearly all SN TH-immunoreactive neurons had strong GIRK2 immunoreactivity compared with only 50-60% of VTA neurons. Most paranigral VTA neurons also contained calbindin immunoreactivity, and approximately 25% of these and nearby VTA neurons also had strong GIRK2 immunoreactivity. These data show that high amounts of GIRK2 protein are found in most SN neurons as well as in a proportion of nearby VTA neurons. The single previous human study may have been compromised by the fixation method used and the postmortem delay of their controls, whereas other studies suggesting that GIRK2 is located only in limited neuronal groups within the SN have erroneously included VTA regions as part of the SN. In particular, the dorsal layer of dopamine neurons directly underneath the red nucleus is considered a VTA region in humans but is commonly considered the dorsal tier of the SN in laboratory species. J. Comp. Neurol. 520: 2591-2607, 2012. (C) 2012 Wiley Periodicals, Inc.},
  author       = {Reyes, Stefanie and Fu, Yuhong and Double, Kay and Thompson, Lachlan and Kirik, Deniz and Paxinos, George and Halliday, Glenda M.},
  issn         = {1096-9861},
  keyword      = {GIRK2,human,mouse,substantia nigra},
  language     = {eng},
  number       = {12},
  pages        = {2591--2607},
  publisher    = {John Wiley & Sons},
  series       = {Journal of Comparative Neurology},
  title        = {GIRK2 Expression in Dopamine Neurons of the Substantia Nigra and Ventral Tegmental Area},
  url          = {http://dx.doi.org/10.1002/cne.23051},
  volume       = {520},
  year         = {2012},
}