Kamondi A, Horváth Z, Bors L, Buzsáki G
Department of Physiology, University Medical School, Pécs, Hungary.
Acta Physiol Hung. 1988;71(1):19-29.
Spatial distribution of field responses evoked by perforant path stimulation were studied in the hippocampus of both anaesthetized and drug-free rats. Simultaneous recordings with an array of 4 electrodes allowed us to construct a 2-dimensional map of the evoked field potentials. In addition, we examined the effects of atropine-SO4 and urethane on the amplitude of the dentate response. Trisynaptic activation of the CA1 region occurred regularly in the drug-free rat while CA1 population spikes were rarely seen in the anaesthetized animal. The latency of the CA1 population spike was shortest at the fimbrial side and increased gradually towards the subicular side. In the dentate gyrus atropine increased the amplitude of the population spike. We suggest that atropine may interfere with the septo-hippocampal feed-forward inhibition, and urethane may decrease the effectiveness of the perforant path-granule cell synapse, as well as the intrahippocampal excitatory circuit.
在麻醉和未用药的大鼠海马体中，研究了穿通通路刺激诱发的场反应的空间分布。使用由4个电极组成的阵列进行同步记录，使我们能够构建诱发场电位的二维图谱。此外，我们研究了硫酸阿托品和乌拉坦对齿状回反应幅度的影响。在未用药的大鼠中，CA1区的三突触激活有规律地发生，而在麻醉动物中很少见到CA1群体峰电位。CA1群体峰电位的潜伏期在海马伞侧最短，并向海马下脚侧逐渐增加。在齿状回中，阿托品增加了群体峰电位的幅度。我们认为，阿托品可能干扰隔海马前馈抑制，而乌拉坦可能降低穿通通路-颗粒细胞突触以及海马内兴奋性回路的有效性。
