On Theta Waves and LTP

Theta waves are low-frequency large-amplitude oscillations (6-7/s) recorded in and around the hippocampus in a variety of mammals, notably rodents, rabbits, and marsupials. Theta rhythms appear to correlate with motor activity, such that their timing coincides with whisker movement and sniffing. These waves are typically investigated with respect to their ostensible involvement in memory, as their power correlates with impairments in memory-related tasks (e.g. spatial alternation, spatial reversal) in lesion studies of the fornix and septum.

Source