4/13/2016 C:\DOCS\MSS\LEARN.HTM http://cogprints.org/761/1/learn.htm 1/9 Physiology & Behavior, Vol. 21, pp. 251256. Pergamon Press and Brain Research PubI., 1978. Copyright © 1978 Brain Research Publications Inc. Learning in Escape/Avoidance Tasks in Female Rats Does Not Vary With Reproductive Condition 1 MARK B. KRISTAL, *2 SEYMOUR AXELROD � AND MICHAEL NOONAN * *Department of Psychology and �Department of Psychiatry State University of New York at Buffalo, Buffalo, NY 14226 (Received 1 February 1977) KRISTAL, M. B., S. AXELROD AND M. NOONAN. Learning in escape/avoidance tasks in female rats does not vary with reproductive condition. PHYSIOL. BEHAV. 21(2) 251256, 1978.  To determine whether the development of novel stimulusresponse associations by the mother during the periparturient period is attributable to a general facilitation of learning produced by the hormonal milieu during that period, learning ability under various reproductive conditions was assessed in two tasks unrelated to the periparturitional situation. The two tasks, selected because they equalized the various groups for motivation and performance variables, were acquisition of a water maze escape (including two reversals), and acquisition and retention of an unsignalled shuttlebox shock avoidance. The groups tested in the water maze were a midpregnant group, an immediately prepartum group, and an immediately postpartum group. In the shuttlebox, the same conditions (different rats) were compared, together with a nonpregnant estrus condition, and a nonpregnant diestrus condition. The results of both experiments indicate that although learning occurred, the characteristics of acquisition and retention were not influenced by reproductive condition. Pregnancy Avoidance Escape Shuttlebox Diestrus Water maze Maternal behavior Estrus Estrous cycle Learning PERINATAL maternal behavior in the rat, as in other altricial mammals, is characterized by an elaborate constellation of caretaking behaviors including placentophagia, retrieval of the neonates to a central nest site, licking of the neonates (especially in the anogenital area), hovering or crouching over the neonates to allow them to nurse, and inhibiting foot and jaw movements that otherwise would lead to injury to the offspring [28,35]. Although the specific motor responses performed by the mother are not novel, the performance of these motor acts in response to the novel stimuli that exist at the first parturition (placenta, pups, etc.) represents a series of entirely new stimulusresponse associations. These new associations arise rapidly in the parturient rat, being evident within minutes of the delivery of the first neonate [28]. These associations are not evident, however, in parturitionally inexperienced females that are not at least on the verge of giving birth. Virgin female rats require days of constant exposure to rat pups before the maternal behaviors are manifested [27]. The difference in latency to maternal behavior between the inexperienced parturient rat and the inexperienced nonpregnant rat has been assumed to be due primarily to the hormonal milieu of the parturient rat; and it has been shown that making the hormonal milieu of the virgin more like that of the parturient female shortens the latency [16,22,30,31,32,36]. The effect of previous parturitional experience on the permanence of maternal behavior is profound. Once the maternal behaviors have been practiced, particularly if they were initiated during the perinatal period, they are subsequently readily elicitable by the external stimuli, even in the absence of brain structures, glands, or hormones that were necessary for the original appearance of the behaviors [4,5,11,15,18,19,23,29]. The development of the novel associations between old motor patterns and new stimuli, and the subsequent incorporation of these stimulusresponse associations into the behavioral repertoire, especially if the association was acquired during parturition, might, for heuristic purposes, be viewed as an instance of very rapid learning. If the stimulus response associations are learned, how