Early life interventions, such as brief separation of pups from their mothers, may permanently affect several brain systems that are not yet mature, such as the stress response system. An animal model quite used to investigate these interventions is neonatal handling. Pups handled in the first two weeks of life have, as adults, less fear and increased locomotion when exposed to a new environment, and also an increased intake of palatable food when compared to non-handled animals. The consumption of high palatable foods may have “comforting” properties and may be consumed when the animal is exposed to aversive or stressful situations. Also, the increased consumption of highly palatable diets is associated with obesity, and overconsumption of sweet foods may be related to an altered brain reward circuits. The aim of this study was to evaluate the effect of neonatal handling on chronic palatable food consumption, and the interaction between these two interventions on stress response and reward system. Wistar rats were handled (10 min/day), or not (control groups), on days 1–10 after birth. Males from these groups were divided into 2 subgroups, receiving standard lab chow or standard lab chow + a highly palatable diet (enriched with simple carbohydrates, made from condensed milk) from postnatal day 21 to 61. Rats receiving the highly palatable diet consumed more food, more calories, gained more weight, but had a lower caloric efficiency than the standard chow groups. The chronic access to a highly palatable diet induced a higher response to an acute stressor, led to higher abdominal fat, plasma leptin and triglycerides, and also a lower preference for novel palatable food. The chronic consumption of food enriched with simple carbohydrates did not appear to be able to change the reward system of these animals, and the neonatal handling had no significant effect on most analyzed parameters. Further investigation is needed to understand how interventions and the type of diet eaten during development affect brain and behavior, which may help to elucidate the mechanisms underlying the alterations in brain and behavior related to eating disorders.
| Identifer | oai:union.ndltd.org:IBICT/oai:lume56.ufrgs.br:10183/108941 |
| Date | January 2014 |
| Creators | Marcolin, Marina de Lima |
| Contributors | Dalmaz, Carla |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, instname:Universidade Federal do Rio Grande do Sul, instacron:UFRGS |
| Rights | info:eu-repo/semantics/openAccess |
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