Theta activity during a long-term potentiation of the hippocampal field CA/sub 1/ and some model notions of the septo-hippocampal complex work

The organization of the septo-hippocampal complex and the functional role of its structures has become the topic of a large body of research. The investigation of the role of the CA/sub 1/ field in the organization of the theta activity is the aim of this work. The investigation was carried out on rats under the functional integrity of the septo-hippocampal system in the natural orienting behavior and that induced by the reticular stimulation. A long-term potentiation (LTP) of synaptic efficacy following high-frequency activation of the Schaffer collaterals formed a zone of an increased excitability in the CA/sub 1/ field. That changed its influence on the septum and the reticular system and was manifested in the modification of the theta activity. The method of the estimation of the signal dimension was used to analyze the theta activity. In contrast to the spectral method it gives an opportunity to take into account some features of its phase structure.