Summary
- We present preliminary experimental evidence for three cholinergically-induced oscillatory regimes in the hippocampal slice observed using field recordings in CA1. Frequencies are within the delta (.5-2Hz), theta (5-10Hz) and gamma (50-90Hz) bands, and depend on the concentration of the neuromodulator (carbachol). We show that these oscillations can occur in a superimposed manner. Moreover, theta can be initiated terminated and phase-reset by afferent stimulations.
- We also show that these oscillations occur with markedly different patterns in the longitudinal slice, in CA3.
- We suggest that the hippocampal circuitry is capable of ‘resonating’ at three frequencies, in the same neuromodulatory conditions. This system offers a framework for the computational modeling of the neuromodulation of a single circuit yielding multiple oscillatory modes.