(A ) DA applied immediately after the pairing protocol with Δt = −20 ms converted t-LTD into t-LTP, whereas delayed application of DA failed to convert t-LTD into t-LTP and either (B ) resulted in a reversal of t-LTD back to baseline (10 min after pairing) or (C ) failed to affect t-LTD altogether (30 min after pairing).
We found that delayed application of DA (10 or 30 min after t-LTD pairing protocol) failed to convert t-LTD into t-LTP.
A third, intriguing explanation arises from findings that LTD-like stimuli (low frequency electrical stimulation or bath application of NMDA) markedly increase actin filament stability in spines (Star et al., 2002).
A third, intriguing explanation, which we favor, arises from a prior report that LTD-like stimulation (low frequency electrical stimulation or bath application of NMDA) markedly increases actin filament stability in spines (Star et al., 2002, Nat Neurosci).
A third, intriguing explanation, which we favor, arises from a prior report that LTD-like stimuli (low frequency electrical stimulation or bath application of NMDA) markedly increase actin filament stability in spines (Star et al., 2002, Nat Neurosci).
Furthermore, application of a D1/D5 receptor agonist facilitates LC-induced CA1 E-LTD into L-LTD that lasts for over 24 h (Lemon and Manahan-Vaughan 2011; Table 1B).
Source data for Figure 2. DOI: http://dx.doi.org/10.7554/eLife.09685.006 Subsequently, we wanted to determine whether the observed DA-induced conversion of t-LTD into t-LTP depends on the timing of DA application following the post-before-pre protocol.
Plasmid DNA was propagated in DH5-α Escherichia coli and was purified using a standard Plasmid Mega Kit (Qiagen Ltd., Crawley, West Sussex, UK); when DNA was prepared for in vivo application, the EndoFree™ Plasmid Mega Kit (Qiagen Ltd).
They found that dopamine application within 10 minutes after STDP pairing could retroactively convert t-LTD into t-LTP.
This effect requires NMDA receptors as application of d -AP5 1 min before the DA application partially blocked the conversion of t-LTD into t-LTP (blue), whereas application of d -AP5 alone failed to influence the development of t-LTD (black).
