抄録
Single unit activity was recorded from the hippocampi (Ammon's horn and fascia dentata) of rats placed in the open-field with a start-box. The units recorded were classified into theta cells (N=6) and complex spike cells (N=9) according to their firing patterns. To detect possible behavioral correlates of activity of these units, the relationships between firing rates (or ratio) and behavioral categories were examined in every I s period. Most of the theta cells (5 out of 6) increased their firing rates during locomotion and sniffing, this activity also being accompanied by theta rhythms in the hippocampal EEG. The remaining theta cell showed a high firing rate also during slow-wave sleep unaccompanied by theta rhythms. Statistically significant differences in firing ratio across behavioral categories were found in 6 out of 9 complex spike cells. In contrast to the theta cells, they exhibited individual patterns which varied from one to another. In addition to these behavioral correlates, place correlates of firing ratios were found in some complex spike cells.
