Objective] The aim of this study was to investigate the electrophysiological characteristics of spontaneous electrical activities of olfactory bulb in Bufo gargarizans during postembryonic development. [Method] Microelectrode technique was used to record extracellular spontaneous electrical activities of olfactory bulb in B. gar-garizans. [Result] Along with the development of olfactory bulb, the discharge types increased gradual y. Single spontaneous firing enhanced gradual y and it reached the maximum in the metamorphosis phase. The intensity of consecutive single sponta-neous firing changed slightly at the middle of post-embryonic development, but it was stil higher than in the early phase and the adult phase. Consecutive burst spontaneous firing frequency went down over time. [Conclusion] Along with the de-velopment of olfactory bulb, the neuronal excitability increases step by step and the neuronal electrical activities diversify gradualy.
Objective To investigate the telencephalon developmental characteristics of Hynobius leehii, and enrich the research data of comparable neurobiology and nervous system development of amphibian. Methods HE staining and Nissl staining methods were used to study the telencephalon histological structure of Hynobius leechii at both the metamorphosis and the adult phases, and to explore the developmental phases of telencephalon. Results The olfactory bulb could be roughly divided into 6 layers from lateral to medial. The lateral cerebral ventricles at the metamorphosis phase were smaller than those at the adult phase, and there were no clear borderlines between the primordial pallium and the primordial hippocampus, or between the primordial pallium and the primordial piriform area. Moreover, the cells in the primordial piriform area were more closely distributed than those in the primordial hippocampus or the primordial pallium. Compared with those at the adult phase, cells in nucleuses at the metamorphosis phase were larger in number and more closely distributed. Conclusion The telencephalon of Hvnobius leehii at the metamorphosis phase has generally formed the adult structure, however, it is still at a transition state of differentiation to maturity during the development of Hynobius leehii.
[Objective] The aim was to probe into developing changes of spontaneous electrical activities of primordial hippocampus in Bufo bufo gargarizans in postembryonic phase. [Method] Microelectrode technique was used to record extracellularly spontaneous electrical activities of neurons in primordial hippocampus of B.bufo gargarizans in postembryonic phase. [Result] Single, consecutive single, burst, consecutive burst and anomalous spontaneous firing were recorded in primordial hippocampus, in which four kinds of spontaneous firings were recorded in forepart of postembryonic development except the anomalous spontaneous firing, and the burst spontaneous firing and consecutive burst spontaneous firing were predominant. The five kinds of spontaneous firings mentioned were recorded in anaphase of postembryonic development and the single and burst spontaneous firing were predominant.Following with the development of primordial hippocampus, the amplitudes of action potential of single firing and consecutive firing enhanced gradually, and it reaches the maximum in the metamorphosis phase; the differences of the frequencies of consecutive single firing and consecutive burst firing were not significant. [Conclusion] Following with the development of primordial hippocampus, the neuronal electrical activities showed diversification, the developmental degree of the primordial hippocampus in the metamorphosis phase was close to the subadult and adult.
