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Rats were administered alcohol during periadolescence (age 30-40 days) and then tested, beginning at 60 days of age, in an aversive-noise passive avoidance task. Relative to a low-dose group and to controls, the animals that had received a high dose were found to be impaired in this task. These results suggest that the developing juvenile is vulnerable to enduring effects of this drug. Thus, risk of impaired development due to alcohol may not be limited to the fetal and neonatal periods but may extend through later postnatal periods as well. Chester F. Bergman constructed the figures. Technical assistance was provided by Janice Hauser, Danny Garland, and Mike Alvis. We thank W. F. Caul and the reviewers for helpful comments on earlier drafts of this paper, Bob Blaszezyk for providing some of the equipment, and M. B. Fletcher for his continued support and encouragement. Correspondence may be sent to G.

Gerbils and rats learned equally well to discriminate the lighted, safe arm from the ul1:saf~ arm duri~g Y.maze avoidance trials, Gerbils, however, were inferior to rats in initiating this response In time to aVOId shock, Two subsequent experiments on passive avoidance did not support the interpretation ~f these data based on a greater incidence of shock·induced activity suppression in gerbils. In both experiments, gerbils required more shocks than rats to learn a staying response, indicating a pronounced locomotor response bias in gerbils that is not compatible with the required passive avoidance response. A four.th experiment, using a shuttlebox, found that the relative active avoidance performance by these species depends upon whether intertrial responses are permitted and punished. When they are, gerbils are inferior to rats, since their high level of locomotor responding is not compatible with the behavior required, i.e., staying during the intertrial interval and running during the CS·US interval. On the other hand, gerbils are not inferior when intertrial responses are prohibited, since their locomotor bias is not punished and is compatible with the required avoidance response.It was suggested by Walters and Abel (1971) that rats and Y·maze tests, The ordinal relationship among the perform passive avoidance better than gerbils while strains in avoidance performance was found to be the gerbils perform active avoidance better than rats. This same in both tasks, However, in the Y-maze all strains observation derives support from a number of compar· learned the brightness discrimination problem equally isons of these species in avoidance tasks. With regard welL This fact, plus the additional findings that the to active avoidance learning, gerbils were superior to better avoiding strains were more active in the shuttle· rats in barpress (Walters, Pearl, & Roger, 1963) and box between trials and showed more locomotor activity two.way shuttlebox (Ashe & McCain, 1972) avoidance dunng the CS·US interval III the Y·maze, supported tasks, In contrast, rats were superior to gerbils in passive a motivational interpretation of the data: Differences avoidance tasks using shock (Galvanni, Riddell, & in avoidance behavior between the strains were due to Foster, 1975;Walters & Abel, 1971) and nonshock strain differences in unconditioned response to shock averSIVe stimulatIOn (Lippman, Galosy, & Thompson, rather than to associative factors per se. Specifically, 1970). Recently, Galvanni et al. (1975) have proVided poor avoidance in two strains of rats was determined eVidence that these species differences in passive avoid-by a marked degree of shock-induced behavioral supance are attributable to a greater tendency for explora· pression which prevented the performance of the tion III gerbils than in rats. required active-avoidance response, whereas superior The present series of studies compared these species avoidance was related to the absence of this incomfurther 111 both active and paSSIve avoidance tasks III patible ...

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