Phencyclidine: effects of chronic administration in the female mouse on gestation, maternal behavior, and the neonates

The ontogeny of phencyclidine-induced wall climbing and locomotor activity

Wall climbing behavior is an age-specific behavior that is elicited during postnatal Days 7 through 17 by various stimuli that include heat, odors, shock, and the catecholaminergic agonists apomorphine, amphetamine, and clonidine. In a previous study, a significant amount of wall climbing behavior was observed during ataxia and activity testing following phencyclidine (PCP) administration in Day 19 but not Day 40 rat pups. The present study describes the ontogeny of PCP-induced wall climbing behavior and locomotor activity. Frequency and duration of wall climbing bouts and locomotor activity were recorded on Days 5, 12, 19, 26, 33, or 40 following PCP treatment. On Day 12, all doses of PCP induced significant amounts of wall climbing behavior. A similar pattern of results was observed on Day 5 although these effects were not statistically significant. After Day 12, PCP-induced wall climbing behavior declined precipitously. PCP increased locomotor activity at all ages tested with maximum activities observed on Day 19. These results demonstrate that PCP-elicited wall climbing behavior follows an ontogenetic profile similar to that previously reported for other stimuli and that there are robust ontogenetic differences in the locomotor response to PCP.

Prenatal phencyclidine in rats: effects on apomorphine-induced climbing

Either 5 or 10 mg/kg of phencyclidine (PCP) in saline was administered by subcutaneous injection to gravid dams during the last two weeks of gestation. A pair-fed control group was administered the vehicle alone and allowed to eat and drink only the amount consumed by the 10 mg/kg group on the same gestation days. A nontreated control group was left undisturbed during pregnancy. All treated and control litters were fostered at birth to untreated dams. Among the dams receiving 10 mg/kg of PCP, food and water intake was initially reduced to 33-43% of nontreated controls, but then returned to control levels. Surprisingly, after 3 days of drug administration, water intake of PCP-treated dams exceeded that of the nontreated dams by approximately 15%. Compared with the nontreated dams, both PCP groups and pair-fed control dams gained significantly less body weight from conception to term. PCP had no significant effect on number of implantation sites or number of live births, however, PCP produced an apparent selective embryolethal effect on males and body weight reduction in all groups at birth. Prenatal PCP did not alter the sensitivity to apomorphine-induced climbing behavior during the second postnatal week. These results are discussed with respect to published animal and clinical studies of PCP exposure during pregnancy.

Effects of prenatal phencyclidine on 3H-PCP binding and PCP-induced motor activity and ataxia

Either phencyclidine hydrochloride (PCP) (5, 10, or 20 mg/kg) or saline was administered by subcutaneous injection to gravid CF-1 mice during either Mid (E6-15) or Late (E12-18) gestation. A nontreated control group (UTC) was left undisturbed during pregnancy. All treated and control litters were fostered at birth to untreated dams. Although postnatal challenge of PCP increased motor activity and ataxia in a dose-related manner, prenatal PCP had no effect on postnatal motor activity, ataxia or 3H-PCP binding. However, treatment period did have a significant effect on ataxia and 3H-PCP binding. In response to challenge doses of 5.0 and 7.5 mg/kg PCP, ataxia scores of the Late gestation offspring were significantly greater than the UTC offspring which in turn were significantly greater than the ataxia scores of the Mid gestation group. The results are discussed in relation to other animal and clinical reports of prenatal PCP exposure.

What happens to babies exposed to phencyclidine (PCP) in utero?

Fifty-seven infants exposed to phencyclidine (PCP) in utero were followed for the first year of life. Thirty-six (65%) of the 55 for whom birth records were available manifested symptoms of neonatal narcotic withdrawal syndrome, including 16 (52%) of those whose mothers denied opiate abuse during pregnancy. Temperament problems were noted in 47% of the babies and sleep problems in 14%. The majority of infants grew normally, but a larger than expected number started out small and remained small. Testing using the Bayley Scales of Infant Development at age one year revealed a mental development index (mean +/- SD) of 94 +/- 10 and a psychomotor development index of 98 +/- 10. Attachment behavior was abnormal in 17%. Most infants were cared for by their natural mother. Further studies are needed to determine later effects of in utero PCP exposure, as well as effects on the infants being raised by women who have used PCP. Phencyclidine toxicity needs to be considered when evaluating babies with signs of neonatal narcotic withdrawal syndrome.

Phencyclidine during pregnancy: fetal brain levels and neurobehavioral effects

Either phencyclidine (PCP) (5, 10, or 20 mg/kg) or saline was administered SC to pregnant CF-1 mice during either MID (E6-E15) or LATE (E12-E18) gestation. Because of the reported prolonged persistence of PCP in adult tissues we first determined its half-life in fetal brain for both treatment periods. PCP appeared rapidly in fetal tissues after maternal administration but was not detected after 8 hours. Then, other treated and control litters were fostered to untreated controls, growth determined and the ontogeny of isolation-induced aggressive behavior examined. Subteratogenic doses of PCP produced mild maternal toxicity without lethality. There was an apparent selective embryolethal effect on males but PCP did not produce an effect on postnatal growth. Prenatal PCP did not alter the ontogeny or intensity of isolation-induced aggressive behavior in male offspring. The results are discussed in relation to other prenatal studies of PCP toxicity and teratogenicity.

Effects of prenatal and perinatal administration of phencyclidine on the behavioral development of rat offspring

The effects of prenatal and perinatal administration of a nonteratogenic dose of phencyclidine (PCP) on the behavioral development of Sprague-Dawley rats were examined. In the offspring prenatally treated with PCP (10 mg/kg) between days 7 and 17 of gestation, a decrease in maternal body weight in the gestation period, a decrease in fetal body weight and body length, a decrease in viability of offsprings, and a decrease in the body weights of the offspring in the nursing period were observed. Furthermore, PCP pups had difficulty performing the rota-rod task at 4 weeks and exhibited a decrease in sensitivity to challenged PCP at 5 weeks (female). In the offspring prenatally treated with PCP between days 7 and 21 of gestation, a decrease in the body weights of dams, fetuses and offspring, and a decrease in the viability of offsprings were observed. PCP pups showed an increase in the score for head-twitch response (male), a delay in the development of ambulation, negative geotaxis (male), bar holding and rope-descending behavior (female). However, the PCP administration during prenatal (between days 17 and 21 of gestation) and nursing periods showed only a decrease in viability and body weight of offspring, and a delay in the development of the separation of eyelids. These results suggest that more attention should be given to the developmental toxicity of PCP.

Phencyclidine exposure and the developing mouse: behavioral teratological implications

The effects of perinatal exposure to phencyclidine (PCP) on the reflex development of the offspring of mothers given PCP during gestation and/or lactation were determined. ICR Swiss mice received daily injections of either PCP (5, 10, 20 mg/kg, PO) or saline during gestation and/or lactation. Thus, four groups of animals were studied; those exposed only prenatally, postnatally, both pre- and postnatally, or control. After birth, these offspring were observed daily until weaning for the appearance of certain reflexes, using a modification of the Fox battery. There was a delay in the disappearance of the cross extensor reflex and delayed appearance of reflexes, such as walking, crawling, vibrissal placement and vibrissal stroking in the offspring of PCP-treated mothers. Treated animals also showed slower righting times than control animals. Growth rate was decreased in PCP-exposed animals beginning at 3 days of age and continuing through 15 days of age. These results indicate that PCP exposure during gestation or nursing adversely affects the development of behavioral reflexes in mice and suggest that regular observation of reflex ontogeny in neonates may be a sensitive indicator of behavioral teratology.

Agenesis of the vermis with fusion of the cerebellar hemispheres, septo-optic dysplasia and associated anomalies. Report of a case

Agenesis of the cerebellar vermis with fusion of the dentate nuclei and cerebellar hemispheres (rhombencephalosynapsis) is a rare cerebral malformation. We report the case of a 7-h-old girl whose mother had taken the drug phencyclidine during the first 6 weeks of pregnancy. Absence of septum pellucidum, hypoplasia of the commissural system, optic nerves, chiasm and tracts, moderate hydrocephalus, and agenesis of the posterior lobe of the pituitary were also found. Extracranial congenital anomalies involved the cardiovascular, respiratory, urinary, and musculoskeletal systems. Death was secondary to severe respiratory distress and bradycardia. The literature concerning this rare form of cerebellar malformation is reviewed.