NEUROBEHAVIORAL TERATOLOGY SOCIETY ABSTRACTS 383

sandwich ELBA method of O’Callaghan (1991) using purified GFAP as standard. Rats exhibited significant increases in GFAP after MA exposure (s.c. 1268% and i.p. 987% above control). Average maximum temperature reached (including a few animals that became hypothermic) was S.C. 40.6’C and i.p. 41 .O’C. Within the limits of the hyperthermia responses, these increases were comparable for both routes of administration (s.c. PcO.0001 and i.p. PcO.0008). Quantitative GFAP will next be used to measure the effects of MA during earlier stages of development. (Supported by NIH grants DA06733 and ES507051).

NBTS 33 MORGAN, RE. *, B. J. STRUPP, D.A. LEVIT- SKY*, and S.A. ALBER”, Div. of Nutri. Sci. & Dept. of Psychology, Cornell University, Ithaca, NY. Effects of low-level lead (Pb) exnosure on reaction time and learning rate in a visual discrimination task: Evidence for the specificity of

the imnairment.

The present study was designed to specify the im- pairment produced by low-level Pb exposure and provide a model system to study the underlying mechanism(s). Long-Evans rats were exposed to 1 of 3 levels of Pb chronically from conception, re- sulting in median steady-state blood Pb levels of <5, 26, and 45 mg/dL. The present report focuses on the results concerning an automated 3-choice visual discrimination task. Although the mean number of sessions to reach criterion did not vary as a fimction of treatment, the incidence of slow learners did in- crease with increasing Pb exposure. Response laten- cy during the block of criteria1 trials was analyzed to determine ifPb exposure affected informationpro- cessing speed. Medianresponselatencywasfound to bepositivelyrelatedtotheprobability ofrespon- ding correctly on a given trial, suggesting a speed- accuracy trade-off.Lead exposure didnot,however, alterreactiontime or this speed/accuracyrelation- ship. These resultshelp specifLthenature ofthe impairmentproducedbylow-level Pb exposure. Although Pb exposurewasrelatedto impairedleam- ing and deficient response inhibition, reaction time

remainedintact. SupportedbygrantsfiomNIEHS &the March ofDimesBirthDefectsFoundation.

NBTS 34 PIZZI, W.J. Northeastern Illinois Univ., Chicago, IL. In utero exposure to phenobarbital results in selective impairment of male offsprins.

Previous studies in our lab with primidone (PRWf which ’ primarily metabolized t': phenobarbital (PHB), suggest that PRM's toxic effects occur in male but not female offspring. The current study was conducted to determine if PHB would selectively target male offspring. Pregnant rats were administered PHB (40 mg/kg, sc) on gestation days 12- 20, while controls received equal amounts of saline. Adult PHB-male rats showed reduced competence on a DRL-20 schedule (~~0.05). PHB- male rats also showed a reduced auditory startle response, but a prepulse inhibition pattern similar to controls. PHB-females showed no differences on these tasks. In a saccharin preference test the usual sex dimorphism was seen in control animals; however, PHB-males drank more of the sweet solution than control males. These results suggest that PHB exposure may reduce testosterone levels at a critical period of brain development leading to feminized behavior in male offspring. SUPPORTED BY NIH GRANT #R15 NS266131.

NBTS 35 RICHARDSON, G., DAY, N. & GOLDSCHMIDT, L. Western Psychiatric Institute & Clinic, 3811 O’Hara Street, Pittsburgh, PA 15213. A longitudinal study of prenatal cocaine exposure: 3-year outcome.

Follow-up of cocaine-exposed offspring beyond the infancy period has been reported by very few researchers. One research group has reported that there were few effects of prenatal cocaine use on