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Updated: May 8, 2026

Study of the Functions and Activities of Neuronal K-Cl Co-Transporter KCC2 Using Western Blotting
Published on: December 9, 2022
Organic cation transporter 2 (SLC22A2), a low-affinity and high-capacity choline transporter, is preferentially
T Nakata1, T Matsui, K Kobayashi
1Department of Health Science, Ishikawa Prefectural Nursing University, 1-1 Gakuendai, Kahoku, Ishikawa 929-1210, Japan; Department of Anatomy and Neurobiology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan.
Abstract:
Organic cation transporters (OCTs) are expressed mainly in the kidney and liver. OCTs transport intrinsic organic cations, including monoamine, dopamine, serotonine and choline, across the plasma membrane. Here, we demonstrate that OCT2 (SLC22A2) is expressed in cholinergic neurons, motoneurons in the anterior horn of the spinal cord, and is implicated in acetylcholine (Ach) recycling in presynaptic terminals. Application of rabbit anti-peptide antibody revealed that OCT2 was expressed in the anterior horn of the spinal cord. Double immunostaining of muscle sections with anti-OCT2 and alpha-bungarotoxin (BTX) revealed that OCT2 was localized in the neuromuscular junctions (NMJs). Immunoelectron microscopy revealed that OCT2 was localized both in synaptic vesicles (SVs) in presynaptic terminals around the motoneurons (C-terminals) and in SVs in nerve terminals in NMJs. The similarity in the distribution of OCT2 in cholinergic neurons and that of vesicular acetyl choline transporter (VAchT), and the fact that OCT2 can transport choline suggest that OCT2 could work as a low-affinity and high-capacity choline transporter at presynaptic terminals in cholinergic neurons in a firing-dependent manner.
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