Intracellular polyamines enhance astrocytic coupling.
Spermine (SPM) and spermidine, endogenous polyamines with the ability to modulate various ion channels and receptors in the brain, exert neuroprotective, antidepressant, antioxidant, and other effects in vivo such as increasing longevity. These polyamines are preferably accumulated in astrocytes, and we hypothesized that SPM increases glial intercellular communication by interacting with glial gap junctions. The results obtained in situ, using Lucifer yellow propagation in the astrocytic syncitium of 21-25-day-old rat CA1 hippocampal slices, showed reduced coupling when astrocytes were dialyzed with standard intracellular solutions without SPM. However, there was a robust increase in the spreading of Lucifer yellow through gap junctions to neighboring astrocytes when the cells were patched with intracellular solutions containing 1 mM SPM, a physiological concentration in glia. Lucifer yellow propagation was inhibited by gap junction blockers. Our findings show that the glial syncitium propagates SPM through gap junctions and further indicate a new role of polyamines in the regulation of the astroglial network under both normal and pathological conditions.
Department of Physiology, Universidad Central del Caribe, School of Medicine, Bayamón, Puerto Rico 00960-6032, USA.
Jan
J
Benedikt
Mikhail
M
Inyushin
Yuriy V
YV
Kucheryavykh
Yomarie
Y
Rivera
Lilia Y
LY
Kucheryavykh
Colin G
CG
Nichols
Misty J
MJ
Eaton
Serguei N
SN
Skatchkov
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000254:growth & development; D002229:Carbenoxolone / Q000494:pharmacology; D002450:Cell Communication / Q000187:drug effects*; D018031:Connexin 43 / Q000502:physiology; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism; D017629:Gap Junctions / Q000187:drug effects / Q000378:metabolism; D015726:Giant Cells / Q000187:drug effects / Q000378:metabolism; D007424:Intracellular Fluid / Q000378:metabolism; D007546:Isoquinolines / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013095:Spermidine / Q000494:pharmacology / Q000502:physiology*; D013096:Spermine / Q000494:pharmacology / Q000502:physiology*
D018031:Connexin 43; D005456:Fluorescent Dyes; D007546:Isoquinolines; D013096:Spermine; C017475:lucifer yellow; D002229:Carbenoxolone; D013095:Spermidine