Early maternal exposure to a high-fat diet (HFD) may influence the brain development of rat offspring and consequently affect physiology and behavior. Thus, in the present study, we investigated the somatic, physical, sensory-motor and neurobehavioral development of the offspring of dams fed an HFD (52% calories from fat, mainly saturated) and the offspring of dams fed a control diet (CD - 14.7% fat) during lactation from the 1st to the 21st postnatal day (P). Maternal body weights were evaluated during lactation. In the progeny, somatic (body weight, head and lengths axes) and physical (ear unfolding, auditory conduit opening, eruption of the incisors and eye opening) development and the consolidation of reflex responses (palm grasp, righting, vibrissa placing, cliff avoidance, negative geotaxis, auditory startle response and free-fall righting) were determined during suckling. Depressive and aggressive behaviors were tested with the forced swimming test (FST) and the "foot-shock" test on days 60 and 110, respectively. The open field test was used to assess motor function. Compared to controls, the HFD-pups exhibited decreases in body weight (P7-P21) and body length (P4-P18), but by days P71 and P95, these pups were overweight. All indicators of physical maturation and the consolidation of the following reflexes, vibrissa placing, auditory startle responses, free-fall righting and negative geotaxis, were delayed in HFD-progeny. In addition, the pups from HFD dam rats also exhibited reduced swimming and climbing times in the FST and increased aggressive behavior. No changes in locomotion were observed. These findings show developmental and neurobehavioral changes in the rat offspring of dams fed the HFD during lactation and suggest possible disruption of physical and sensory-motor maturation and increased susceptibility to depressive and aggressive-like behavior.

The increasing prevalence of overweight and obesity is a global public health problem that affects both sexes and all age groups, especially women in reproductive age 1 . Currently 65% of the population in the world lives in countries in which obesity causes more deaths than malnutrition 2 . Moreover, the induced-high fat diet (HFD) maternal obesity has risen dramatically over the past 20 years, by nearly 42% in African-Americans and 29% in Caucasians 3 . Within this context, fetuses and newborns are increasingly exposed to maternal HFD which may cause problems in growth and brain deve lopment 4 . However, few stu dies ha ve investigated the effects of maternal HFD on the brain development of the offspring 5,6, particularly isolating or separating the periods of pregnancy and lactation. On the other hand, most studies have evalua ted the effects of maternal obesity or HFD intake along gestation and lactation, hindering the identification of AbstrAct:The maternal exposure to high fat diet (HFD) during pregnancy and breastfeeding have been considered an important inducer of alterations in offspring normal programming, both in animals and humans, and may disturb brain development. In the present study we investigated the somatic and sensory-motor development of the offspring from rat dams fed a HFD, compared with dams fed a control diet, during pregnancy or lactation. Indicators of the body growth, physical maturation, and reflex ontogeny were evaluated. Offspring of dams fed a HFD showed reduced weight and body growth, delayed physical maturation, and delayed maturation of the physiological reflexes, such as vibrissa placing, auditory startle response, and free-fall righting. Our findings suggest that maternal HFD during pregnancy or lactation modifies somatic and neurological development of the offspring, possibly increasing the risk of neuroendocrine and neuropsychiatric disorders later in life.Keywords: high fat diet, pregnancy, lactation, somatic growth, reflex ontogeny, offspring. resuMo:A exposição materna a dieta rica em gordura (DRG) durante a gravidez e a amamentação tem sido considerada um importante indutor de alterações da programação normal da prole, em animais e humanos, e pode atrapalhar o desenvolvimento do cérebro. No presente estudo, investigamos o desenvolvimento somático e sensório-motor da prole de ratas alimentadas com uma DRG, em comparação com ratas alimentadas com uma dieta controle, durante a gravidez ou lactação. Foram avaliados indicadores de crescimento corporal, maturação física e ontogênese de reflexos. A prole de ratas alimentadas com DRG mostrou redução de peso e crescimento do corpo, atraso da maturação física e maturação tardia de reflexos fisiológicos, tais como colocação pelas vibrissas, resposta ao susto e reação de aceleração. Nossos resultados sugerem que DRG materna durante a gravidez ou lactação modifica desenvolvimento somático e neurológico da prole, possivelmente aumentando o risco para distúrbios neuroendócrinos e neuropsiquiátricos mais tarde na vida.Palavras-chave: ...

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