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This report dealt with the change of body temperature (rectal temperature) in the newborn cynomolgus monkeys (Macaca fascicularis) with a view to take it as an index for their health conditions. The body temperatures of 183 newborn babies which were well cared for by their mothers was 33.0 to 37.7 degrees C about 10 hr after birth. On the other hand, the body temperatures of 21 newborn babies which were not well cared for by their mothers was very low, ranging from 24.1 to 34.8 degrees C. In five newborn monkeys which were well cared for, the body temperature averaged about 36 degrees C just after birth and then declined rapidly by 32 to 33 degrees C at 40 to 50 minutes after birth. Then it gradually began to rise, reaching 36 to 37 degrees C at 180 to 240 min after birth. In the other four newborn monkeys which were delivered by Caesarean section, the temperature was 37 to 38 degrees C just after birth. Then it decreased to 29 to 32 degrees C at 120 minutes after birth when the newborns remained singly in a cage without warming.

The classical righting reflexes have been well illustrated in the familiar example of a falling adult cat, which always lands deftly on all four feet. It, however, has never been clear when newborn animals come to turn themselves in the air after birth. In the present studies the newborn cats were dropped in the air with legs pointed upward from a height of about 30 approximately 40 cm, and the observations were continued for the period of 36 days. The results were as follows: 1. The newborn cats fell plump on their back when they were dropped with legs pointed upward in the air. 2. No righting reflexes were observed in the cats of 27 days and downward. 3. The eyelids (rima palpebrarum) of the cats came to be open on the 8th approximately 14th after birth. 4. The cats which were suggested to obtain full eyesight judged from the observations of their behaviours had no visual righting reflexes when dropped with legs pointed upward. 5. The walking pattern of the cats changed in association with their growth. For the period of 20 days after birth the type of locomotion was creeping, for the period of 21st approximately 26th plantigradation, and after the 26th approximately 27th digitigradation. 6. It has been concluded that the righting reflexes as compound reflexes are never observed in the experimental cats for about one month after birth even though the cats have obtained each postural reflex, i.e. tonic neck or labyrinthine reflex which constitutes righting reflexes.

Perinatal and postnatal study on netilmicin (NTL), a new aminoglycoside antibiotic, was carried out in Sprague-Dawley rats (Slc : SD). NTL was administered intramuscularly from day 17 of gestation throughout day 20 after delivery at the daily dose of 12.5, 25, 50 and 100 mg/kg. Water intake of pregnant and nursing dams was increased in the animals treated with 50 mg/kg or more of NTL. The increase of cecum weight was observed in F1 animals in all treated groups at 3 weeks of age. However, birth rate, suckling rate, weanling rate, body weight, postnatal development, behavior and reproductive function remained within normal ranges in all treated groups.

Guanabenz (WY-8678) was given to rats to examine its effects on dams and offspring in terms of influence on postnatal development emotion, learning and reproductive ability. The drug was administered orally to rats at 15, 8, 5, 2 and 1 mg/kg/day from the 17th day of gestation to the 21st post-partum day. The vehicle used was 5%-Arabic Gum at dose level of 5 ml/kg and a control experiment where only vehicle was administered was also conducted. The results obtained were as follows. 1. In observation of the dams, increase in body weight tended to be repressed after administration in the 8 mg/kg group, and in the 15 mg/kg group body weight decreased. Food consumption and water intake tended to be suppressed in the 15 mg/kg group. During nursing, changes of body weight, food consumption and water intake were not influenced by Guanabenz in each group. 2. The drug produced sedation, abnormal walking, decrease in a reflex test and lacrimation of red exudate in dams. 3. In the 15 mg/kg group, the length of gestation was prolonged. Furthermore, abnormal delivery and nursing were observed, and in one-third of dams in the 8 mg/kg group and in all dams of 15 mg/kg group, the still-birth of all offspring was observed. No difference was observed among groups as to the organ weights at weaning. 4. In observation of the offspring, differences were observed in the viability rate and the weaning rate. No difference was observed among groups as to the viability rate, changes of body weight, postnatal development, and behavioral development on the 7th day. No differences were observed in each group regarding emotion, motion, perception and learning. 5. No difference was observed among groups in the reproduction test. As to symptoms seen in gestation, the dams and fetuses were not influenced by dosage of Guanabenz. From these results, the safe dose level seems to be below 5 mg/kg/day.

Changes of serum concentrations of LH were measured in fetal and neonatal rats following castration. Intact fetal and neonatal male rats showed low levels of serum LH concentration. Though serum LH levels of male rats casterated on the 20th day of gestation did not significantly increase by the 22nd day of fetal age, serum levels of neonatal male rats increased 2-to 3-fold 3 days following castration at all ages studied. The increase was greater in 4-day-old male rats than in 1-day-old males. The increase of serum LH after castration was also found in 4-day-old male rats castrated on the 20th day of gestation. In contrast, serum levels of 1-day-old neonatal female rats did not increase 3-days after castration. These observations suggest sex differences in maturation of the gonadal-hypophyseal feedback mechanism.

The drugs used were pargyrine, methamphetamine, reserpine, norepinephrine, epinephrine, propranolol, chlorpromazine, 6-hydroxydopamine, haloperidol, pilocarpine, neostigmine and atropine. The body The weight gain of pups receiving reserpine, chlorpromazine, 6-hydroxydopamine and pilocarpine was significantly inhibited. The mortality of pups given reserpine was significantly increased. The behavioral development of righting reflex, cliff drop avoidance and negative geotaxis of rats given reserpine, propranolol, 6-hydroxydopamine and haloperidol was significantly retarded in comparison with that of control pups. Spontaneous motor activity measured by Animex was increased in pups receiving norepinephrine, epinephrine, chlorpromazine, reserpine, propranolol and atropine. Furthermore, pharmacological challenge by the injection of methamphetamine exhibited an accentuated response to an increase in spontaneous motor activity in pups exposed to chlorpromazine, reserpine, propranolol, 6-hydroxydopamine and atropine. These findings suggest that an increase in spontaneous motor activity may be induced by the developmental impairment of central catecholamine mechanisms, especially the noradrenaline nervous system. Delayed latency, decreased rearing and preening of pups receiving propranolol were observed on the open field test. The conditioned avoidance responses using the shuttle box revealed deficits in acquisition of avoidance learning of rats given haloperidol, 6-hydroxydopamine and propranolol, suggesting that the learning deficits may be due to the developmental impairment of catecholamine mechanisms, especially the dopamine nervous system.

The preference and physical dependence for morphine, changes in gross behaviors and growth were investigated in the offspring of pregnant rats treated with morphine. Six groups (A-F) of the pregnant rats were treated with morphine by DAF (drug-admixed food) method for the following periods. No morphine-treatment was received in group A, treatment form the beginning of pregnancy (day 0) to weaning in group B, from day 0 to day 14 in group C, from day 15 to day 21 in group D, from day 0 to weaning in group E (the same of B), and no treatment in group F. The pups of group E were fostered to maters of group F, and pups of group F, and pups of group F were to maters of group E. The preference rate for morphine in pregnant rats increased significantly in comparison with of non-pregnant rats. Weanling rates of group B, C, D and E decreased significantly when compared with that of group A. The pups of maternal rats treated with morphine showed hyperactivity and vocalization. These symptoms were considered to be resulted from the withdrawal signs. The withdrawal signs may produce the decrease in the weanling rates. There was no difference in body weight gains in the offspring between group A and B. Preference rate for morphine in the offspring of group B was lower than that of group A. It may be due to an enhanced susceptibility to morphine in group B. However, no marked change in intensity of physical dependence on morphine was detected in the offspring between group A and B.

Post-natal manifestation of circadian rhythms was examined in individual rats in order to clarify the manner in which pups' circadian oscillation entrained to the maternal circadian system. Ablation of the hypothalamic suprachiasmatic nucleus (SCN), a putative circadian pacemaker, completely eliminated the circadian rhythms of spontaneous locomotor activity and plasma corticosterone level in pregnant rats. However, all pups born to mothers whose SCN were lesioned at day 10 of gestation showed free-running circadian rhythms of plasma corticosterone level with similar phase angles after the 4th week of postnatal life. Strong positive correlations between the phases of circadian locomotor rhythm at the day of weaning and each free-running period (tau) were observed in blinded pups nursed under identical lighting schedule (LD). The fact suggests that the individual circadian oscillation was in phase on a certain day before the weaning. Mother-pups exchange under reversed lighting schedule (LD and DL) and nursing under 4-hourly restricted daily feeding (RF) indicated that nursing mother rat could essentially phase-set the circadian locomotor rhythm of blinded pups when the conditions during nursing were artificially modified. The weight of neonatal rats was measured every 4 hours from day 1 to day 3 and day 9 to day 10 after birth, and 4-hourly weight gains showed apparent circadian periodicity from day 2 of age. Under ad-lib feeding of mother rats, pups' weight mainly increased during daytime but the phase of weight rhythm shifted under RF corresponding to the feeding time of the mother. These findings suggest that the circadian oscillation underlying the spontaneous locomotor activity and plasma corticosterone level in rats has entrained to the maternal circadian system during fetal life, and nursing mother is capable of phase-setting the circadian oscillation of blinded pups probably through the rhythmicity of the lactation.