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Ontogenesis of the cerebellofugal projection in the rat
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ONTOGENY OF SUBSTANCE P IN THE MONKEY CEREBRAL CORTEX: AN IMMVNOHISTOCHEMICAT, AKIKO YAMASHITA , MOTOHARU HAYASHI, KEIKO SHIMIZU STUDY. AND KIYOSHI OSHIMA , Department of Physiology, Primate Research Institute, Kyoto University, Kanrin, Inuyama, Aichi 404, Japan. To investigate the role of neuropeptides in neural development, we studied the distribution pattern of substance P (SP)-immunoreactive structures in the macaque monkey cerebral cortex at embryonic day 120 (E120), newborn, E140, postnatal day 30 (P30), P60 and adult stages using an ABC immunohistochemical method. The SP-immunoreactive cells and fibers were observed throughout all stages. The number of immunoreactive cells increased until the newborn stage. At El40 and newborn stages, we observed intense concentrations of immunoreactive After those stages, the cell number decreased and cells in the lower layers. reached the adult level at P60. Among various areas, there existed slight differences in the distribution patterns of the immunoreactive cells. In the occipital cortex, the cell numbers were small and there were little changes during development. The largest number of immunoreactive cells were observed in the temporal cortex. In the previous study, we have also observed transient increases in concentration and in cell number of somatostatin at near-term period. Some neuropeptides, including substance P and somatostatin, may be involved in the development of monkey cerebral cortex.
ONTOGENESIS OF THE CEREBELLOFUGAL PROJECTION IN THE RAT. SABVRO KAWAGVCHI, MIYAHIKO MURATA*, AND YASUO KVRIMOTO*, Institute for Brain Research, Faculty of cedicine, Kyoto University, Kyoto 606, Japan. Ontogenesis of the cerebellofugal projection was studied in the rat by the tract tracing method and recording the cerebellar-induced cerebral response. At various ages ranging from embryo to adult, the projection was labeled anterogradely with wheat germ agglutinin-conjugated horseradish peroxidase that was injected into the cerebellum under deep anesthesia. was found to begin entering Thus, the projection thebrainstematembyonicday17 (E17) and to reach the most rostra1 part of the thalamus already by E18, distributing dense terminals to various brainstem and thalamic nuclei. The course and termination of this projection at El8 were largely similar to, but partly different from those in the adult. Terminals present in the interpeducular nucleus and basal ganglia at El8 regressed and disappeared during ontogenesis, whereas the recrossed ipsilateral projection to the thalamus which were absent at El8 developed postnatally. Then, the adult pattern of the projection was achieved by 3 to 4 weeks of age.Stimulationofthecerebellar nuclei under a moderate level of chloral hydrate anesthesia could induce a surface negative, depth positive wave in the cerebral cortex as early as 2 days postpartum. While the waveform of response remained unchanged during development, the latency from 50-60 msina Z-day-oldpupto 4-5 ms of responsedecreasedmarkedly withage, in adult rats.
ONTOGENY OF SUBSTANCE P IN THE MONKEY CEREBRAL CORTEX: AN IMMVNOHISTOCHEMICAT, AKIKO YAMASHITA , MOTOHARU HAYASHI, KEIKO SHIMIZU STUDY. AND KIYOSHI OSHIMA , Department of Physiology, Primate Research Institute, Kyoto University, Kanrin, Inuyama, Aichi 404, Japan. To investigate the role of neuropeptides in neural development, we studied the distribution pattern of substance P (SP)-immunoreactive structures in the macaque monkey cerebral cortex at embryonic day 120 (E120), newborn, E140, postnatal day 30 (P30), P60 and adult stages using an ABC immunohistochemical method. The SP-immunoreactive cells and fibers were observed throughout all stages. The number of immunoreactive cells increased until the newborn stage. At El40 and newborn stages, we observed intense concentrations of immunoreactive After those stages, the cell number decreased and cells in the lower layers. reached the adult level at P60. Among various areas, there existed slight differences in the distribution patterns of the immunoreactive cells. In the occipital cortex, the cell numbers were small and there were little changes during development. The largest number of immunoreactive cells were observed in the temporal cortex. In the previous study, we have also observed transient increases in concentration and in cell number of somatostatin at near-term period. Some neuropeptides, including substance P and somatostatin, may be involved in the development of monkey cerebral cortex.
ONTOGENESIS OF THE CEREBELLOFUGAL PROJECTION IN THE RAT. SABVRO KAWAGVCHI, MIYAHIKO MURATA*, AND YASUO KVRIMOTO*, Institute for Brain Research, Faculty of cedicine, Kyoto University, Kyoto 606, Japan. Ontogenesis of the cerebellofugal projection was studied in the rat by the tract tracing method and recording the cerebellar-induced cerebral response. At various ages ranging from embryo to adult, the projection was labeled anterogradely with wheat germ agglutinin-conjugated horseradish peroxidase that was injected into the cerebellum under deep anesthesia. was found to begin entering Thus, the projection thebrainstematembyonicday17 (E17) and to reach the most rostra1 part of the thalamus already by E18, distributing dense terminals to various brainstem and thalamic nuclei. The course and termination of this projection at El8 were largely similar to, but partly different from those in the adult. Terminals present in the interpeducular nucleus and basal ganglia at El8 regressed and disappeared during ontogenesis, whereas the recrossed ipsilateral projection to the thalamus which were absent at El8 developed postnatally. Then, the adult pattern of the projection was achieved by 3 to 4 weeks of age.Stimulationofthecerebellar nuclei under a moderate level of chloral hydrate anesthesia could induce a surface negative, depth positive wave in the cerebral cortex as early as 2 days postpartum. While the waveform of response remained unchanged during development, the latency from 50-60 msina Z-day-oldpupto 4-5 ms of responsedecreasedmarkedly withage, in adult rats.