Deconstructing the function of maternal stimulation in offspring development: Insights from the artificial rearing model in rats

Resilience priming: Translational models for understanding resiliency and adaptation to early life adversity

“…Moreover, several of the first papers published in the original issue of Developmental Psychobiology focused on the effects of early life experience, such as handling (Altman, Das, & Anderson, ; Denenberg, Karas, Rosenberg, & Schell, ; Levine, ; Thoman, Levine, & Arnold, ) on later outcomes. In fact, the very first article in the original issue, by Victor Denenberg et al (), addressed how early life stress (ELS) can “program life histories.” Since that time, several models of ELS have evolved including protocols of social isolation, chronic mild stress, restraint stress, and administration of drugs or viral/bacterial mimetics (Abdul Aziz, Kendall, & Pardon, ; Baker et al, ; Blaze et al, ; Borrell, Vela, Arévalo‐Martin, Molina‐Holgado, & Guaza, ; Connors, Migliore, Pillsbury, Shaik, & Kentner, ; Connors, Shaik, Migliore, & Kentner, ; Fatemi et al, ; Kehoe, Hoffman, Austin‐LaFrance, & Bronzino, ; Lorenz, ; Maccari et al, ; Meyer et al, ; Rangon et al, ; Schmitz et al, ; Weinberg, ; Yan & Kentner, ), as well as models using more prolonged maternal separation periods (reviewed in Maccari et al, ; Tractenberg et al, ; Lomanowska, Boivin, Hertzman, & Fleming, ; Lomanowska & Melo, ), or limited bedding as a model of ELS (Blaze & Roth, ; Doherty, Forster, & Roth, ; Gilles, Schultz, & Baram, ; Heun‐Johnson & Levitt, ; Walker et al, ). Each of these models can affect maternal care, which may mediate the alterations in neurodevelopment, thus highlighting the challenge of understanding the impact of early life experiences.…”

“…Importantly, methylation levels may differ by genotype, and genetic variations in itself can predict the risk for vulnerability to later‐life stressors, thus adding another level of complexity when trying to understand the pathways to resilience or sensitivity after early life adverse experiences (Brummelte et al, ). For excellent reviews on the role of genetic predispositions and gene‐environment interactions in mediating resilience or vulnerability to ELS see: Lomanowska & Melo, ; Bowes & Jaffe, , Feder, Nestler, & Charney, , Daskalakis, Bagot, Parker, Vinkers, & Kloet, .…”

The Drosophila foraging gene human orthologue PRKG1 predicts individual differences in the effects of early adversity on maternal sensitivity

“…Adverse early experiences can affect mothers' cognitive and executive functions, including their working memory, decision-making, and attention to the environment, including infant cues (Gonzalez et al, 2012; Pawluski, Lambert, & Kinsley, 2016; Plamondon et al, 2015). Early adversity also affects mothers' stress regulation and responsitivity (Pereira et al, 2012) through dysregulation of the hypothalamic-pituitary-adrenal axis (Gonzalez et al, 2012) and regulation of neurochemistry and brain function important for mothering (Lomanowska & Melo, 2016). …”

Early postnatal development of electrophysiological and histological properties of sensory sural nerves in male rats that were maternally deprived and artificially reared: Role of tactile stimulation

“…In addition, they show disturbed emotional responses (anxiety, depression, and stress responses), deficits in cognition (attention, impulsivity, memory, and learning), and increased locomotor activity (Gonzalez et al, ; Levy et al, ; Lovic and Fleming, ; Lomanowska et al, ; Lovic et al, ). Furthermore, AR disrupts the development of most of the neurobiological substrates that underlie many of the behaviors affected (see Melo, ; Lomanowska and Melo, ). Thus, AR rats show reduced levels of c‐Fos immunoreactivity (Gonzalez and Fleming, ; Akbari et al, ), altered dendritic morphology (Shams et al, ), altered levels of proteins involved in the maturation of neurons and glial cells (Chatterjee et al, ) and disturbed levels of neurotransmitters (Afonso et al, ; Hidalgo‐Flores et al, ), among other changes, in many brain areas involved in social and emotional behaviors and cognitive process (medial preoptic area, ventromedial hypothalamus, amygdala, nucleus Accumbens, prefrontal cortex, raphe, etc.).…”

“…Thus, AR rats show reduced levels of c‐Fos immunoreactivity (Gonzalez and Fleming, ; Akbari et al, ), altered dendritic morphology (Shams et al, ), altered levels of proteins involved in the maturation of neurons and glial cells (Chatterjee et al, ) and disturbed levels of neurotransmitters (Afonso et al, ; Hidalgo‐Flores et al, ), among other changes, in many brain areas involved in social and emotional behaviors and cognitive process (medial preoptic area, ventromedial hypothalamus, amygdala, nucleus Accumbens, prefrontal cortex, raphe, etc.). Importantly, if AR pups receive artificial tactile stimulation that simulates the mother's licking, or are reared alongside two age‐matched conspecifics, most of the effects are prevented (Gonzalez et al, ; Melo et al, ; see, Lomanowska and Melo, ). These data strongly suggest that mother‐infant interactions and/or sibling interactions are essential for the normal development of social behaviors and their underlying neural substrates at the brain level.…”