Alcohol consumption in neonatal rats produces cerebellar damage and is widely used to model 3 rdtrimester human fetal alcohol exposure. Neonatal "binge-like" exposure to high doses of alcohol (5 g/kg/day or more) impairs acquisition of eyeblink classical conditioning (EBC), a cerebellardependent Pavlovian motor learning task. We have recently found impairments in interstimulus interval (ISI) discrimination -a complex task variant of EBC -in adult rats following postnatal day (PD) 4-9 alcohol exposure at doses of 3, 4, and 5 g/kg/day. Because robust developmental differences in conditioned response (CR) generation and CR latency measures are present between untreated juveniles and adults in this task, we sought to extend alcohol findings to juvenile rats (PD30). Five neonatal treatment groups were used: (1) undisturbed controls, (2) sham intubation controls, (3) 3 g/ kg/day of alcohol (blood alcohol concentration {BAC} = 139.9 mg/dl), (4) 4 g/kg/day of alcohol (BAC = 237.3 mg/dl), or (5) 5 g/kg/day of alcohol (BAC = 301.8 mg/dl). Intubations occurred over PD4-9. ISI discrimination training in juveniles (PD30-33) revealed dose-dependent CR deficits in all three alcohol-exposed groups relative to controls. Contrary to expected outcomes, CR latency measures were not significantly affected as a function of neonatal treatment. Comparison of these findings with our recent study in adults suggests that alcohol-induced impairments in ISI discrimination EBC may be greater in adults relative to juveniles. The present findings provide further evidence that ISI discrimination may provide greater sensitivity to functional deficits resulting from moderate levels of neonatal alcohol exposure relative to single-cue EBC paradigms. KeywordsFetal alcohol syndrome; eyeblink conditioning; neonatal alcohol; juvenile rat 1 1. Introduction Prenatal alcohol exposure in humans is among the leading preventable causes of mental retardation in the Western world (Abel and Sokol, 1986). The term fetal alcohol spectrum disorders (FASD) has been applied to characterize the range of deficits present in individuals Corresponding author: Kevin L. Brown, Department of Psychology, Temple University, Philadelphia, PA 19122, brownkev@temple.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. 1 Abbreviations: ANOVA, analysis of variance; BAC, blood alcohol concentration; CR, conditioned response; CS, conditioned stimulus; EBC, eyeblink classical conditioning; EMG, electromyogram; FAS, fetal alcohol syndrome; FASD, fetal alcohol spectrum disorders; Group 3g/4g/5g, dosed with 3/4/5 g/kg/day of alcohol; Gro...