Here’s an old and difficult to access paper (Download: Commins & O’Mara Psychobiol) of ours from Psychobiology – from the days before all journals were online. Hard to remember those days now…
(This is the longest title on any paper I have ever published…)
Commins, S. & O’Mara, S.M. (2000). Interactions Between Paired-Pulse Facilitation, Low-Frequency Stimulation And Behavioral Stress In The Pathway From Hippocampal Area CA1 To The Subiculum: Dissociation Of Baseline Synaptic Transmission From Paired-Pulse Facilitation And Depression Of The Same Pathway. Psychobiology, 28, 1-11.
The interaction between low-frequency stimulation (LFS; 900 stimuli at 10 Hz) of field excitatory postsynaptic potentials (fEPSPs) and paired-pulse facilitation (PPF; 50 & 100msec inter-stimulus intervals) was investigated in the projection from hippocampal area CA1 to the subiculum. We also investigated if LTD can be obtained in the subiculum using a stress protocol (previously described to induce LTD effectively in vivo in area CA1 of the hippocampus; Xu et al., 1997a). Finally, we examined the interaction between the stress treatment and PPF. There was no significant difference between fEPSP amplitude measured at 30 mins post-LFS (10 Hz) when compared with baseline fEPSP peak amplitude; PPF, however, increased significantly 30 mins post-LFS when compared to PPF pre-LFS for both 50msec and 100msec intervals.‘ These results indicate that there is a dissociation between single-pulse stimulation and paired-pulse stimulation of the CA1-subiculum pathway. The combined effect of stress and LFS produced a depression in synaptic response of 56.99% at 5 mins post-LFS and 10.23% at 30 mins post-LFS. Behavioral stress combined with LFS caused a significant decrease in PPF at 30 mins post-stimulation. At 50msec ISI, facilitation is minimal and at 100msec paired-pulse depression occurs. These data suggest that there are possibly previously undescribed mechanisms regulating transmission in this pathway.
Key Words: Paired-pulse facilitation, low-frequency stimulation, subiculum, long-term depression, behavioral stress.