Neuronal sources of theta rhythm in the entorhinal cortex of the rat
Neuronal sources of theta rhythm in the entorhinal cortex of the rat
复制标题
大鼠内嗅皮层θ节律的神经元来源
作者：
A. Alonso;E. Garcı́a
摘要对麻痹大鼠和局部麻醉大鼠注射毒豆碱诱导θ (θ)节律的放电模式和内嗅皮质（EC）单元的层状分布进行了研究。用同一微管同时记录内嗅单位活性和场电位。以海马CA1 θ节律为参照。统计分析包括自相关、互相关和间隔直方图。结果表明：a.有节奏细胞和无节奏细胞的存在，均倾向于与θ节奏呈恒定相位关系；b.在所有EC细分中，大多数节律细胞位于细胞表层（II-III）；c.平均而言，来自内侧脑脊液的节律细胞同步放电；D.非节律性细胞也倾向于同步放电，但与节律性神经元具有相反的相位关系。虽然揭示了电浆单元节律性的复杂组织，但结论是电浆中θ活动的神经元来源位于浅表细胞层，并强烈建议通过穿孔路径输出的电浆可能有节律地调节海马锥体和齿状颗粒细胞的放电模式。
SummaryThe discharge patterns and layer distribution of entorhinal cortex (EC) units were investigated in paralysed and locally anesthetized rats injected with physostigmine in order to induce theta (θ) rhythm. Entorhinal unit activity and field potentials were recorded simultaneously with the same micropipette. Hippocampal CA1 θ rhythm was used as reference. Statistical analysis included auto- and cross-correlations and interval histograms. Results showed: a. the existence of rhythmic and non-rhythmic cells, both tending to fire in a constant phase relationship with θ rhythm; b. in all EC subdivisions, most rhythmic cells were located in superficial cell layers (II–III); c. on the average, rhythmic cells from the medial EC fired synchronously; d. non-rhythmic cells tended also to fire synchronously but with an opposite phase relationship with respect to rhythmic neurons. Although a complex organization in the rhythmicity of EC units is revealed, it is concluded that the neuronal sources of θ activity in the EC are located in superficial cell layers, and it is strongly suggested that the EC output through the perforant path may rhythmically modulate the discharge pattern of hippocampal pyramidal and dentate granule cells.