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Potassium channel subunit Kv3.2 and the water channel aquaporin-4 are selectively localized to cerebellar pinceau.
Brain Res. 2004 Nov 12; 1026(2):168-78.BR

Abstract

The pinceau is a cerebellar structure formed by descending GABA-ergic basket cell axonal terminals converging on the initial axonal segment of Purkinje cell. Although basket cells exert a powerful inhibitory influence on the output of the cerebellar cortex, the function and mode of action of the pinceau are not understood because the majority of basket cell axons fail to make identifiable synaptic contacts with the Purkinje cell axon. Several proteins were previously reported to cluster specifically in this area, including a number of voltage-activated potassium channel subunits. In this study, we used immunohistochemistry, electron microscopy, and electron tomography to examine the ultrastructural localization of a novel voltage-gated potassium channel subunit, Kv3.2, in the pinceau. We found strong, selective localization of Kv3.2 to basket cell axons. Additionally, because potassium buffering is often conducted through water channels, we studied the extent of a brain-specific water channel, aquaporin-4 (AQP4), using confocal and electron microscopy. As expected, we found AQP4 was heavily localized to astrocytic processes of the pinceau. The abundance of potassium channels and AQP4 in this area suggests rapid ionic dynamics in the pinceau, and the unusual, highly specialized morphology of this region implies that the structural features may combine with the molecular composition to regulate the microenvironment of the initial segment of the Purkinje cell axon.

Authors+Show Affiliations

Department of Neurosciences, National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093-0608, USA.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

15488478

Citation

Bobik, Marketta, et al. "Potassium Channel Subunit Kv3.2 and the Water Channel Aquaporin-4 Are Selectively Localized to Cerebellar Pinceau." Brain Research, vol. 1026, no. 2, 2004, pp. 168-78.
Bobik M, Ellisman MH, Rudy B, et al. Potassium channel subunit Kv3.2 and the water channel aquaporin-4 are selectively localized to cerebellar pinceau. Brain Res. 2004;1026(2):168-78.
Bobik, M., Ellisman, M. H., Rudy, B., & Martone, M. E. (2004). Potassium channel subunit Kv3.2 and the water channel aquaporin-4 are selectively localized to cerebellar pinceau. Brain Research, 1026(2), 168-78.
Bobik M, et al. Potassium Channel Subunit Kv3.2 and the Water Channel Aquaporin-4 Are Selectively Localized to Cerebellar Pinceau. Brain Res. 2004 Nov 12;1026(2):168-78. PubMed PMID: 15488478.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Potassium channel subunit Kv3.2 and the water channel aquaporin-4 are selectively localized to cerebellar pinceau. AU - Bobik,Marketta, AU - Ellisman,Mark H, AU - Rudy,Bernardo, AU - Martone,Maryann E, PY - 2004/07/31/accepted PY - 2004/10/19/pubmed PY - 2005/2/3/medline PY - 2004/10/19/entrez SP - 168 EP - 78 JF - Brain research JO - Brain Res. VL - 1026 IS - 2 N2 - The pinceau is a cerebellar structure formed by descending GABA-ergic basket cell axonal terminals converging on the initial axonal segment of Purkinje cell. Although basket cells exert a powerful inhibitory influence on the output of the cerebellar cortex, the function and mode of action of the pinceau are not understood because the majority of basket cell axons fail to make identifiable synaptic contacts with the Purkinje cell axon. Several proteins were previously reported to cluster specifically in this area, including a number of voltage-activated potassium channel subunits. In this study, we used immunohistochemistry, electron microscopy, and electron tomography to examine the ultrastructural localization of a novel voltage-gated potassium channel subunit, Kv3.2, in the pinceau. We found strong, selective localization of Kv3.2 to basket cell axons. Additionally, because potassium buffering is often conducted through water channels, we studied the extent of a brain-specific water channel, aquaporin-4 (AQP4), using confocal and electron microscopy. As expected, we found AQP4 was heavily localized to astrocytic processes of the pinceau. The abundance of potassium channels and AQP4 in this area suggests rapid ionic dynamics in the pinceau, and the unusual, highly specialized morphology of this region implies that the structural features may combine with the molecular composition to regulate the microenvironment of the initial segment of the Purkinje cell axon. SN - 0006-8993 UR - https://www.unboundmedicine.com/medline/citation/15488478/Potassium_channel_subunit_Kv3_2_and_the_water_channel_aquaporin_4_are_selectively_localized_to_cerebellar_pinceau_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0006-8993(04)01251-X DB - PRIME DP - Unbound Medicine ER -