Connexin expression in electrically coupled postnatal rat brain neurons

Connexin expression in electrically coupled postnatal rat brain neurons

^*Department of Clinical Neurobiology, University Hospital for Neurology, Im Neuenheimer Feld 364, and ^‡Max-Planck-Institut für Medizinische Forschung, Jahnstrasse 29, D-69120 Heidelberg, Germany

Edited by Michael V. L. Bennett, Albert Einstein College of Medicine, Bronx, NY, and approved June 16, 2000 (received for review January 28, 2000)

Abstract

Electrical coupling by gap junctions is an important form of cell-to-cell communication in early brain development. Whereas glial cells remain electrically coupled at postnatal stages, adult vertebrate neurons were thought to communicate mainly via chemical synapses. There is now accumulating evidence that in certain neuronal cell populations the capacity for electrical signaling by gap junction channels is still present in the adult. Here we identified electrically coupled pairs of neurons between postnatal days 12 and 18 in rat visual cortex, somatosensory cortex, and hippocampus. Notably, coupling was found both between pairs of inhibitory neurons and between inhibitory and excitatory neurons. Molecular analysis by single-cell reverse transcription–PCR revealed a differential expression pattern of connexins in these identified neurons.

Footnotes

↵ † Present address: Laboratoire de Neuropharmacologie INSERM U-114, College de France, 11 Place M. Berthelot, 75005 Paris, France.
↵ § To whom reprint requests should be addressed at: Max-Planck-Institut für Medizinische Forschung, Jahnstrasse 29, D-69120 Heidelberg, Germany. E-mail: monyer{at}mpimf-heidelberg.mpg.de.
This paper was submitted directly (Track II) to the PNAS office.
Article published online before print: Proc. Natl. Acad. Sci. USA, 10.1073/pnas.160037097.
Article and publication date are at www.pnas.org/cgi/doi/10.1073/pnas.160037097
Abbreviations:

Cx,

connexin(s);

RT-PCR,

reverse transcription–PCR;

Pn,

postnatal day n;

IR-DIC,

infrared-differential interference contrast;

GABA,

γ-aminobutyrate