It has previously been shown that medial fornical lesions can selectively disrupt the hippocampal theta rhythm in rats, whereas the major hippocampal input and output systems remain functionally intact. However, selective theta disruption did not affect the performance of well-trained jump avoidance responses that are usually accompanied by clear theta waves. Therefore, the main purpose of the present study was to investigate whether theta activity proves necessary for the acquisition of the jump task. In addition, it appeared of interest to test the potential effects of theta disruption on open-field behavior, since medial septal lesions that most likely destroy theta have been reported to cause decreased locomotor activity in the open field. The present results show that the occurrence of theta activity is not necessary for avoidance acquisition or normal open-field behavior. These findings give further support to the notion that the theta rhythm may be a correlate of internal hippocampal processes rather than of some overt behavior. © 1977 Academic Press, Inc.
Myhrer, T. (1977). Jump avoidance acquisition and locomotor behavior in rats with the hippocampal theta rhythm disrupted. Behavioral Biology, 19(3), 361–370. https://doi.org/10.1016/S0091-6773(77)91731-X