Delayed Formation of Neonatal Reflexes and of Locomotor Skills Is Associated with Poor Maternal Behavior in OXYS Rats Prone to Alzheimer’s Disease-like Pathology

Abstract

Postnatal brain development is characterized by high plasticity with critical windows of opportunity where any intervention may positively or adversely influence postnatal growth and lead to long-lasting consequences later in life. Poor maternal care is among these interventions. Here, we found that senescence-accelerated OXYS rats prone to an Alzheimer’s disease-like pathology are characterized by more passive maternal behavior and insufficient care for pups as compared to control (Wistar) rats. OXYS pups demonstrated a delay in physical development (of auricle detachment, of emergence of pelage and incisors, of eye opening, and of vaginal opening in females) and late manifestation of reflexes and locomotor skills. All observed behavioral abnormalities are connected either with poor coordination of limbs’ movements or with a decrease in motivation and development of depression-like behavior. It is possible that their manifestations can be promoted by the features of maternal behavior of OXYS rats. Overall, these early-life events may have long-lasting consequences and contribute to neurodegeneration and development of the Alzheimer’s disease-like pathology later in life.

The Rat Brain Transcriptome: From Infancy to Aging and Sporadic Alzheimer’s Disease-like Pathology

“…To answer the main question, changes in which signaling pathways and processes become the most pronounced in the delayed maturation of the brain in OXYS rats [ 22 , 23 , 37 ], and to determine their potential role in the development of AD signs later in life [ 20 ], here we evaluated the transcriptomic changes in the PFC and hippocampus of OXYS and Wistar rats at the earliest stages of their postnatal life. It is believed that the level of brain development of rat pups at P1–P3 is similar to the level of human brain development at 23–32 weeks of gestation, and the level of brain development of rat pups at P7–P10 is equivalent to 36–40 weeks of gestation or the child brain at birth [ 38 ].…”