Using a Developmental Ecology Framework to Align Fear Neurobiology Across Species

Abstract

Children's development is largely dependent on caregiving; when caregiving is disrupted, children are at increased risk for numerous poor outcomes, in particular psychopathology. Therefore, determining how caregivers regulate children's affective neurobiology is essential for understanding psychopathology etiology and prevention. Much of the research on affective functioning uses fear learning to map maturation trajectories, with both rodent and human studies contributing knowledge. Nonetheless, as no standard framework exists through which to interpret developmental effects across species, research often remains siloed, thus contributing to the current therapeutic impasse. Here, we propose a developmental ecology framework that attempts to understand fear in the ecological context of the child: their relationship with their parent. By referring to developmental goals that are shared across species (to attach to, then, ultimately, separate from the parent), this framework provides a common grounding from which fear systems and their dysfunction can be understood, thus advancing research on psychopathologies and their treatment.

Adverse caregiving in infancy blunts neural processing of the mother

“…Only the final reunion data from the SSP and rSSP is used to determine attachment quality (outlined in red). The SSP child subjects were 11-28 months old, while rat pups were PN13-14, an age range across species associated with some mobility and complete dependence on the caregiver for survival 15 .…”

Adverse caregiving in infancy blunts neural processing of the mother: Translating across species

“…Such translation is made possible by the fact that the human SSP was originally designed to be ecologically relevant to the young altricial infant who is mobile but still depends on the parent for soothing check-ins if stressed or anxious. This developmental ecology is maintained across the human, nonhuman primates, and rodent infant 12 . In the rSSP, as in the human SSP, 7 epochs are comprised of separations, reunions, and introductions of a "stranger" rat mother, produced by changing the maternal odor via the diet (see Supp.…”

“…Only the final reunion data from the SSP and rSSP is used to determine attachment quality. The SSP child subjects were 11-28 months old, while rat pups were PN13-14, an age range across species associated with some mobility and complete dependence on the caregiver for survival 12 .…”

Annual Research Review: Critical windows – the microbiota–gut–brain axis in neurocognitive development

“…However, equating P16 in a rodent to 6 months in a human does not necessarily match on to estimates of neurodevelopment, which can vary wildly depending on the metric of interest. For example, some place a P16 rodent at the equivalent of 2–3 human months based on physical characteristics (Clancy et al, ), or more than 2 human years based on the development of attachment relationships and fear neurocircuitry (Callaghan et al, ). Thus, it will be important to consider the specific developmental trajectories of different aspects of neurodevelopment when attempting to predict how studies of the microbiota in model species will translate to humans.…”