This exploratory study attempted to uncover behavioral and physical outcomes of changes in the peripheral SMS system in the first postnatal week. On postnatal days 1-7, Sprague-Dawley rat pups received daily s.c. injections of Somatostatin (SMS; 8 or 40 μg/kg), saline, or CPP-1 (8 or 40 μg/kg), a putative SMS receptor antagonist. Physical growth and neurobehavioral development of the pups, assessed on days 3, 6, 9 and 12, were not affected, in 3 separate replications (n = 11/treatment/ replication). In contrast, neonatal CPP-1 (40 μg/kg) reduced separation distress on day 14, as measured by ultrasonic vocalization and activity. In addition, neonatal SMS (40 μg/kg) tended to impair learning on a milk-rewarded Y-maze on days 15-16. These findings support further examination of the potential role of SMS in behavioral development.
Bibliographical noteFunding Information:
Please address all correspondence to: Dr. Aron Weller, Department of Psychology, Bar Ilan University, Ramat Gan, Israel. Bitnet: F41410 @ BARILVM. FAX: 972-3-5351825. Work in the Developmental Psychobiology laboratory is supported by the National Institute for Psychobiology in Israel-The Charles E. Smith Family Foundation; The Yigal Alon Fund and a Bar-Ilan University internal research fund, all to A. W. The authors express their gratitude to Prof. Shlomo Yehuda for critical review of the manuscript and to Mor Segal, Limor Chen, Eli Yarden, Miriam Yanoov and three teams of experimenters, for help in the research.
- Neonatal rats
- Neurobehavioral development
- Ultrasonic vocalization