LITTER SIZE ADJUSTMENT IS A FACTOR INFLUENCING ON THE PHYSIC AND NEUROBEHAVIORAL PUP?S DEVELOPMENT

SOLER GARCIA FLORENCIA M; SANCHEZ SUSANA INES; FUENTES LUCIA BEATRIZ; SOLER GARCIA FLORENCIA M; SANCHEZ SUSANA INES; FUENTES LUCIA BEATRIZ

Merlo- San Luis

Congreso; XXXV Reunion de la Sociedad de Biologia de Cuyo; 2017

Sociedad de Biología de Cuyo

Postnatal development involves maturation of several systems. The appearance of neurological reflexes is influenced by various factors such as nutrition, maternal care and littermate interactions. The aim of this study was to evaluate alterations in physical and neurobehavioral development on normal (NL) and small litter (SL) pups. Wistar rat litters were selected as: NL (12.40±0.81 pups) or SL (gradually adjusted by sacrificed 2-3 pups in 0, 3, 5, 7 and 15 postnatal day (PND). Pups were evaluated on physical landmarks and behavioral indicators (n=18/each test). Litter size adjustment induced a significant increased in body weight (SL: 32.62±0.80 g vs NL: 23.13±0.68 g, p˂0.001) and length (SL: 8.55±0.07 cm vs NL: 7.83±0.06 cm, p˂0.001) at PND15. The determination of physical signs reveals a significant decrease in vibrissa growth (SL: 0.86±0.02 cm vs NL: 1.10±0.06 cm, p˂0.01) and pinna detachment (SL: 46.43±3.57 % vs NL: 60.00±3.27 %, p˂0.01) during first postnatal week and eye opening in PND15 (SL: 45.24±9.70 % vs NL: 73.33±9.59 %, p˂0.05). Neurobehavioral tests results in increased righting reflex (SL: 5.19±1.16 sec vs NL: 10.50±0.97 sec, p˂0.01) and negative geotaxis during first postnatal week (SL: 33.33±0.00 % vs NL: 13.88±7.34 %, p˂0.05). Open field test shows increase motion time (SL: 48.39±4.06 % vs NL: 34.41±2.43 %, p˂0.05) and decrease grooming time (SL: 4.85±1.09 % vs NL: 17.03±2.50 %, p˂0.001). The results indicate that litter size adjustment modifies the physical and motor development of pups and should be take into account for an adequate application in the field of neurodevelopment.