A single subcutaneous injection of 30 mmole/kg of monosodium glutamate was given to pregnant mice on day 16, 17 or 18 of pregnancy. The brains of fetuses were examined microscopically 3, 6 and 24 hours after treatment. Offspring of the treated mothers were weighed weekly, their tail length measured and the reproductive function examined. Brain lesions characterized by cellular pyknosis and intracellular edema were found in the medial preoptic area, hypothalamic arcuate and ventromedial nucleus. But, these changes seemed to disappear 24 hours after treatment. Offspring in the group treated on day 18 were heavier in mean body weight and shorter in mean tail length than controls.

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1. Toad larvae were reared at a high temperature of 33 ± 1℃ after the limb bud stage. 2. These larvae frequently showed anomalies in their feet, such as fusion or contiguousness of toes I and II, hypophalangism in toes III-V and outward protrusion in the middle part of the metatarsus produced by inward flexion of metatarsale V. 3. Syndactylism was usually by means of the soft tissue only, with one exception. In a single osseous syndactylia, phalanges of toes I and II were fused while metatarsalia I and II were separated. 4. The cause of these malformations was discussed.

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Functional and behavioral studies were carried out in male adult Wistar rats born from the mothers which had been treated by phenylhydrazine hydrochloride (i.p.) during pregnancy. Experimental subjects having had neonatal severe jaundice and anemia showed the followings: 1) On general reflexes no systematic significant difference was found although a few individual abnormal deviations were observed. 2) On the spontaneous motility no between-group difference was found. However, in individual cases was found a certain degree of hyper- or hypoactivity. 3) Conditioned avoidance learning (one-way active avoidance) was found to be significantly retarded in acquisition and disappeared faster in extinction. This work was supported in part by Japanese Ministry of Health and Welfare Grant on the Cause and Prevention of the Developmental Disabilities. We thank ex-Professor U. Murakami, director of our Institute, for his kindly reading the manuscript and Misses Ohta, Hasui, Takasu and Seo for their technical assistance. (Received on, May 25, 1974)

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Suckling mice were injected subcutaneously with cytosine arabinoside (ara-C), a drug known to interfere with DNA synthesis. The animals were divided into three experimental groups. Group I received a dosage of 30 mg/kg, group 2, a dosage of 50mg/kg and group 3, a dosage of 100 mg/kg. The animals belonging to three groups were injected subcutaneously with this chemical on postnatal days 2, 3 and 4 successively. Subsequently these animals and control animals were sacrificed on postnatal days 5, 7, 15, 20 and 30, and their cerebella were examined microscopically. The results were summarized as follows. 1. On postnatal day 5, the external granular layer of treated animals was sellectively damaged and almost completly disappeared. The Purkinje cells, however, remained normal. 2. In groups 1 and 2, repair of the external granular layer was noticed on postnatal day 10 and 15, respectively. Repair of the external granular layer was prominent in the posterior lobes. 3. Sizes of cerebe lum of 30-day-old treated animals were smaller than those of age-matched controls. 4. Cytoarchitecture of cerebella of 20- and 30-day-old treated animals differed greatly from that of control. In the anterior lobes of the treated cerebellum, the Purkinje cells were dispersed throughout the molecular layer and granule cells were few in the granular layer. In the middle and posterior lobes, the Purkinje cells were arranged irregularly and granule cells were numerous in the granular layer. However, some cells were remained in the molecular layer, thus forming heterotopic granule cell mass. 5. Most animals belonging to groups 2 and 3 showed ataxic gait and tremor.

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