Session: 8

PS8-05 | Neonatal obesity: implications for memory impairment and neurosteroidogenesis dysregulation.

Maria Florencia Rossetti

Instituto de Salud y Ambiente del Litoral (ISAL), CONICET-UNL

The objective was to explore the importance of neonatal overnutrition on cognition and on the transcriptional control of steroidogenic enzymes. For that, rats were raised in small litters (4 pups/mother; SL), in which pups ingest larger amounts of milk and gain more body weight than rats raised in normal litters (10 pups/mother; NL). On PND21, half of the male rats were sacrificed (SL21 vs NL21; 8 pups/group) and the rest of males were maintained under standard conditions until PND90 (SL90 vs NL90; 14 rats/group). At PND90, animals were tested in locomotion activity (LA) and episodic-like memory (ELM). After two weeks, they were sacrificed and brains were microdissected. Using micropunch techniques, DG, CA1 and CA3 regions were isolated for mRNA and methylation quantification (results under analysis).
At PND21, SL21 animals had higher body and fat patches weights and greater levels of cholesterol, glucose and triglycerides, than NL21 rats. However, these metabolic differences were not observed at PND90. No differences were found in LA test, although SL90 rats reported a significantly increased of depositions than NL90 animals. During ELM, NL90 rats showed a very good test performance, while SL90 rats exhibited no clear preference during object exploration. Up to now, these results showed that neonatal obesity in males affects cognitive functions in adulthood, suggesting a long-lasting effect of nutritional experience during critical periods of early postnatal development.