Studies On Histological And Electrophysiological Characteristics In Process Of Occurrence And Development Of Telencephalon Of Hynobius Leechii

ObjectiveIn order to probe into the occurrence and development of telencephalon of Hynobius leechii and to establish a dynamic pattern of telencephalon's development, methods of morphology and histology were applied. At the same time, the method of electrophysiology was applied to study the relationship between construction and function of telencephalon during the development phases of Hynobius leechii.MethodsThe appearances of telencephalon of Hynobius leechii were observed under an anatomical lens and were taken photos by Moticam1300 figures camera. Paraffin slices were made and were stained by Nissl and HE-staining methods. The system of RM6240 was used to collect and handle physiological signals in electrophysiology study.ResultsTelencephalon of Hynobius leechii can be divided into two parts, cerebral hemisphere and olfactory bulb. In the development phases of Hynobius leechii, cerebral hemisphere embryo shaped in heart palpitates phase. And then, the percentage of cerebral hemisphere increased gradually and was closed to the adult phase. The olfactory bulb developed lately. Its embryo form appeared in hind limb bud phase, and formed bunch in metamorphosis period, and maturated in adult phase.The appearance of nerve system of Hynobius leechii began from neural tube phase. Cerebral hemisphere embryo shaped in heart palpitates phase of Hynobius leechii. And then, the cells propagated and migrated gradually. They differentiated into different kinds of cells and formed cerebral cortex zone in forelimb bud phase, which was coated by membrane tissues. Primordial hippocampus and amygdale appeared in hind limb phase, which was not developed. Primordial hippocampus, primordial pallium, primordial piriform area, striatal complex and olfactory bulb appeared in metamorphosis period. Ventricles of the hemisphere stretched into rostra tip portion of cerebral hemisphere. Olfactory bulb was not developed. Cellular distribution was the densest in this phase. Through large numbers of cellular apoptosis, regiment of nucleus formed the end fixed position in telencephalon. During the first stage of development of telencephalon occurrence, amplitudes of recorded firings were only more than ten and tiny votes in vivo. Firing time was long. The quantity was little. Excitability of neurons was very low. From outside-gill phase to heart palpitates phase, amplitude of firings increased largely. Firing time became short and the category and quantity increased. Excitability of neurons increased. During the phases of telencephalon's development, firing time became shorter and the category and quantity increased again. Excitability of neurons increased gradually. To the adult phase, amplitude of firings attained the biggest value.ConclusionDuring the development of Hynobius leechii, the appearance of telencephalon shows marked gradually. Cerebral hemisphere embryo shapes in heart palpitates phase. Regiment of nucleus forms the fixed position in telencephalon in metamorphosis phase. Through a flood of cell apoptosis, telencephalon becomes mature. Following the occurrence and development of telencephalon, excitability of neurons increases gradually, the neuron's electricity movable form becomes diverse gradually. In a word, the process of occurrence and development of telencephalon of Hynobius leechii is from simple to complicate and from low to high level. Following the structure of telencephalon forms, the function of telencephalon consummates gradually.