Laminar distribution of hippocampal rhythmic slow activity (RSA) in the behaving rat: current-source density analysis, effects of urethane and atropine.

摘要: Abstract This study investigated the laminar distribution of rhythmic slow wave activity (RSA) in dorsal hippocampus rat during running. Depth analyses field EEG were performed by stepping recording electrode 82.5 μm increments and sampling RSA at each depth. One-dimensional current-source density (CSD) was calculated from profiles to enhance spatial resolution current sources sinks. Laminar analysis power, coherence, phase with respect a stationary stratum oriens CA1 spectral methods. waves CA1-dentate axis had power maxima about hippocampal fissures, hilus, outer molecular layer endal leaf dentate gyrus CA1, that order. A gradual shift occurred radiatum CA1. Large phase-shifts found both ectal leaves fascia dentata. null zone associated sudden phase-reversal observed lucidum CA3. Multiunit showed phase-locked modulation granule cell dendate pyramidal CA3, subiculum. CSD revealed multiple source-link pairs. The sinks cyclic changes RSA, attributed rhythmic, but time-shifted, afferents septum entorhinal cortex. phase-shift configurational depth, are explained summation extracellular currents produced time-delayed sink-source pairs (RSA dipoles). When cholinergic septohippocampal path blocked atropine middle became steeper. Under urethane anesthesis present inner RSA. Urethane reduced hilus decreased firing rate cells. It is suggested several rhythmical dipoles along somadendritic surface cells spatiotemporal relations individuals determine actually