Subscribe to thousands of academic journals for just $40/month
Read and share the articles you need for your research, all in one place.

Combined β-adrenergic and corticosteroid receptor activation regulates AMPA receptor function in hippocampal neurons

Journal of Psychopharmacology , Volume 26 (4): 516 – Apr 1, 2012


Sage Publications
Copyright © 2012 by SAGE Publications
Publisher site
See Article on Publisher Site

Preview Only

Expand Tray Hide Tray

Combined β-adrenergic and corticosteroid receptor activation regulates AMPA receptor function in hippocampal neurons


Shortly after stress, limbic neurons are exposed to high levels of noradrenaline and corticosterone. These hormones are necessary for optimal behavioural adaptation. Behavioural effects critically depend on noradrenaline acting via β-adrenergic receptors, but these effects are strongly modulated by corticosterone, indicating putative interactions between the two hormones. Since both noradrenaline and corticosterone are known to quickly affect properties of AMPA-type glutamate receptors (AMPAR), we here examined – in hippocampal neurons – three parameters which give insight in the functionality of AMPARs: phosphorylation, surface expression and spontaneous synaptic transmission. In homogenates of adult hippocampal slices, application of corticosterone (30 nM for 15 min) by itself did not affect phosphorylation of the AMPAR GluA1 subunit at S845 or S831. Co-application of the β-adrenergic receptor agonist isoproterenol (10 µM) largely increased S845 (but not S831) phosphorylation. Corticosterone also did not change GluA1 and GluA2 surface expression in hippocampal primary cultures. However, combined administration of corticosterone and 1 µM isoproterenol – which by itself was ineffective – enhanced surface expression. Interestingly, 10 µM isoproterenol alone enhanced GluA1 surface expression, but this was decreased by corticosterone. Finally, in hippocampal primary cultures, the inter-event interval of miniature excitatory postsynaptic currents (mEPSCs) was decreased by the combination of 1 µM isoproterenol and corticosterone (which were ineffective by themselves) while the same combination did not affect the amplitude. We conclude that AMPAR phosphorylation, surface expression and mEPSC inter-event interval respond most strongly to a combination of corticosterone and β-adrenergic receptors. These combined hormonal effects on glutamate transmission might contribute to their memory-enhancing effects.
Loading next page...

Preview Only. This article cannot be rented because we do not currently have permission from the publisher.