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Neonatal handling alters feeding behavior of adult rats
P P Silveira1, A K Portella, Z Clemente
1Department of Biochemistry, Instituto de Ciências Básicas da Saúde, UFRGS, Ramiro Barcelos, 2600 (Anexo) Lab. 32, 90035-003 Porto Alegre, Rio Grande do Sul, Brazil. raty@cpovo.net
Insights
Neonatal stress from handling or tactile stimulation in rats increases adult consumption of palatable snacks. This heightened intake of sweet and savory foods persists into old age, suggesting long-term central nervous system changes.
Area of Science:
- Neuroscience
- Behavioral Science
- Developmental Biology
Background:
- Neonatal stress can induce lasting behavioral and biochemical changes in adulthood.
- Early life experiences significantly shape adult feeding behaviors and physiological responses.
Purpose of the Study:
- To investigate the long-term effects of neonatal handling and tactile stimulation on adult feeding behavior in rats.
- To determine if early life stress influences the consumption of palatable foods in later life.
Main Methods:
- Rat litters were divided into intact, handled, and handled+tactile stimulated groups from postnatal Days 1-10.
- Adult rats were tested for consumption of sweet and savory snacks, standard chow, water, and glucose/saline solutions.
- Behavioral tests were repeated at 15 months of age to assess long-term effects.
Main Results:
- Rats subjected to neonatal handling or tactile stimulation consumed significantly more sweet and savory snacks as adults compared to controls.
- These effects were consistent in both male and female rats.
- No significant differences were observed in body weight, standard chow intake, water consumption, or intake of glucose/saline solutions.
Conclusions:
- Neonatal handling and tactile stimulation induce persistent alterations in the central nervous system (CNS) of rats.
- These early-life interventions lead to increased consumption of palatable foods in adulthood, a change that endures throughout their lifespan.
Abstract:
Stress during the neonatal period leads to a large number of behavioral and biochemical alterations in adult life. The aim of this study is to verify the effects of handling and tactile stimulation during the first 10 days of life on feeding behavior in adult rats. Litters were divided into (1). intact; (2). handled (10 min/day); and (3). handled and tactile stimulated (10 min/day). Procedures were performed on Days 1-10 after birth. When adults, rats were tested for ingestion of sweet and savory snacks. We also measured body weight, ingestion of standard lab chow, and consumption of water and 1% glucose and 1.5% NaCl solutions. Stressed rats (handling and handling+tactile stimulation groups) consumed more sweet (two-way ANOVA, P=.008) or savory snacks (P=.001) than intact ones. This effect was observed in males and females. There were no differences in body weight, ingestion of standard lab chow, water, or in the ingestion of sweetened or salty solutions between groups. The same animals were tested later in life (15 months of age), and the effect was still evident. We suggest that handling during the neonatal period leads to alterations in the CNS of rats, causing an increased ingestion of palatable food in adult life, and this alteration probably persists throughout the whole life.
