β-Adrenergic receptor activation has a central role in the enhancement of memory formation that occurs during heightened states of emotional arousal. Although β-adrenergic receptor activation may enhance memory formation by modulating long-term potentiation (LTP), a candidate synaptic mechanism involved in memory formation, the cellular basis of this modulation is not fully understood. Here, we report that, in the CA1 region of the hippocampus, β-adrenergic receptor activation selectively enables the induction of LTP during long trains of 5 Hz synaptic stimulation. Protein phosphatase inhibitors mimic the effects of β-adrenergic receptor activation on 5 Hz stimulation-induced LTP, suggesting that activation of noradrenergic systems during emotional arousal may enhance memory formation by inhibiting protein phosphatases that normally oppose the induction of LTP.
Bibliographical noteFunding Information:
Correspondence should be addressed to T. J. O. This work was supported in part by a grant from the National Institute of Mental Health (MH52876) and by an Esther A. and Joseph Klingenstein Fellowship in the Neurosciences to T. J. O.; T. D. M. was supported by the Achievement Rewards for College Scientists program. We are grateful to Drs. David Glanzman, Eric Kandel, and Frank Krasne for comments on an earlier version of the manuscript.