Journal of Behavioral and Brain Science, 2019, 9, 362-374 https://www.scirp.org/journal/jbbs ISSN Online: 2160-5874 ISSN Print: 2160-5866 DOI: 10.4236/jbbs.2019.910027 Oct. 18, 2019 362 Journal of Behavioral and Brain Science Juvenile Play Behavior in Neonatally Underfed and Sensory Stimulated Wistar Rats Manuel Salas * , Mirelta Regalado, Carmen Torrero, Minerva Ortiz-Valladares Department of Developmental Neurobiology and Neurophysiology, Institute of Neurobiology, University of Mexico, Campus UNAM Juriquilla, Queretaro, Mexico Abstract Play development in juvenile rats depends on specific sensory signals inte- grated at cortical, limbic and brain stem levels to modulate motoric, metabol- ic, motivational and social responses. Neonatal undernourishment disrupts the morphological and functional organization of the brain for adaptive res- ponses including play performance. These alterations may be restored by preweaning exposure to sensory-enriched environments. This study was de- signed to determine in four experimental groups, Control (LC), Underfed (LU), Control Ligated/Stimulated (LCS), and Underfed Ligated/Stimulated (LUS), whether changes in juvenile play of neonatally underfed male rats by the nipple-ligated procedure of F0 dams and/or the handling of F1 rats may restore the deficiencies in juvenile play performance. The pinning frequency values in LC, LCS and LUS groups consistently increased until reaching a sig- nificant peak between postnatal days (PDs) 25 and 50 and then gradually de- clining until PD 60, when the play in pairs was significantly higher compared with the play in groups that follows the same sequence but with lower values in the stimulated groups. The results may reflect poor maternal care and low- er somatosensory stimulation; and the sensory massage of LU F1 pups com- pared with the LC, LUS, and LCS rats. Fewer dorsal body contacts occurred in LU and LUS rats when playing in pairs than in groups. Results suggest that although handling has salutary effects on neuronal play structures, the re- duced levels of total pinning and dorsal contacts, mainly in the play of rat pairs in LCS vs. LUS groups, were not fully recovered. Keywords Juvenile Play, Early Handling, Neonatal Undernutrition, Rats 1. Introduction During the lifespan of rats, the neuronal mechanisms underlying juvenile play How to cite this paper: Salas, M., Regala- do, M., Torrero, C. and Ortiz-Valladares, M. (2019) Juvenile Play Behavior in Neo- natally Underfed and Sensory Stimulated Wistar Rats. Journal of Behavioral and Brain Science, 9, 362-374. https://doi.org/10.4236/jbbs.2019.910027 Received: September 1, 2019 Accepted: October 15, 2019 Published: October 18, 2019 Copyright © 2019 by author(s) and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access