Two Types of Cl Transporters Contribute to the Regulation of Intracellular Cl Concentrations in ON- and OFF-type Bipolar Cells in the Mouse Retina.
Neuroscience
; 440: 267-276, 2020 08 01.
Article
em En
| MEDLINE
| ID: mdl-32531472
ABSTRACT
In the retina, ON- and OFF-type bipolar cells are classified by subtype-specific center responses, which are attributed to differences in glutamate receptor subtypes. However, the mechanisms by which ON- and OFF-type bipolar cells generate subtype-specific surround responses remain unclear. One hypothesis for surround responses is that intracellular Cl concentrations ([Cl-]i) are set at different levels to achieve opposite polarities for GABA responses in ON- and OFF-type bipolar cells. Although this hypothesis is supported by previous findings obtained from rod (ON-) type bipolar cells, there is currently no information on OFF-type bipolar cells. In the present study, we examined the distribution and function of the Cl transporters, the Na-K-Cl co-transporter (NKCC1) and K-Cl co-transporter (KCC2), in rod (ON-) and OFF-type bipolar cells using immunohistochemical, in situ hybridization, and electrophysiological methods. Rod (ON-) and OFF-type bipolar cells both expressed NKCC1 and KCC2. However, the functional contribution of NKCC1 and KCC2 to the regulation of [Cl-]i differed between rod (ON-) and OFF-type bipolar cells. Strong NKCC1 activity increased [Cl-]i in rod (ON-) type bipolar cells, while that of KCC2 decreased [Cl-]i in OFF-type bipolar cells. We also confirmed the presence of a [Cl-]i gradient between dendrites and axon terminals in rod (ON-type) bipolar cells. Thus, the subtype-specific control of [Cl-]i is achieved by the activity of NKCC1 relative to that of KCC2 and appears to influence the polarity of surround responses.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Simportadores
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Simportadores de Cloreto de Sódio-Potássio
Limite:
Animals
Idioma:
En
Revista:
Neuroscience
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Japão