Long-term effects of the perinatal environment on respiratory control

Abstract

The respiratory control system exhibits considerable plasticity, similar to other regions of the nervous system. Plasticity is a persistent change in system behavior triggered by experiences such as changes in neural activity, hypoxia, and/or disease/injury. Although plasticity is observed in animals of all ages, some forms of plasticity appear to be unique to development (i.e., “developmental plasticity”). Developmental plasticity is an alteration in respiratory control induced by experiences during “critical” developmental periods; similar experiences outside the critical period will have little or no lasting effect. Thus complementary experiments on both mature and developing animals are generally needed to verify that the observed plasticity is unique to development. Frequently studied models of developmental plasticity in respiratory control include developmental manipulations of respiratory gas concentrations (O2 and CO2). Environmental factors not specifically associated with breathing may also trigger developmental plasticity, however, including psychological stress or chemicals associated with maternal habits (e.g., nicotine, cocaine). Despite rapid advances in describing models of developmental plasticity in breathing, our understanding of fundamental mechanisms giving rise to such plasticity is poor; mechanistic studies of developmental plasticity are of considerable importance. Developmental plasticity may enable organisms to “fine tune” their phenotype to optimize the performance of this critical homeostatic regulatory system. On the other hand, developmental plasticity could also increase the risk of disease later in life. Future directions for studies concerning the mechanisms and functional implications of developmental plasticity in respiratory motor control are discussed.

Resuscitation of Hypoxic Newborn Piglets With Supplementary Oxygen Induces Dose-Dependent Increase in Matrix Metalloproteinase-Activity and Down-Regulates Vital Genes

“…Developmental plasticity during critical periods of maturation may result in long-term alterations like blunting of adult hypoxic response after early postnatal hyperoxia exposure, reviewed in Ref. 39. The results of this study, determined in such a critical time window, could contribute to shed light on possible pathologic long-term alterations of this developmental plasticity.…”

Thoracoabdominal mobility evaluation by photogrammetry in newborns after expiratory flow increase technique

“…After positioning, adhesive markers were allocated to the following points: [1] anterior superior iliac spines and [2] level of the jugular notch of the sternal manubrium, projected laterally. These references served as an anchor for the geometric delimitation of the thoracoabdominal compartment in the acquired images during photogrammetry (Figure 1).…”

Neonatal stress and attenuation of the hypercapnic ventilatory response in adult male rats: the role of carotid chemoreceptors and baroreceptors

“…With regard to respiratory regulation, several recent reviews have highlighted the profound effects of excessive stimulation of chemosensory pathways (e.g., intermittent hypoxia, chronic hypoxia) on the developmental trajectory of the neural circuits that regulate breathing (2,7). Depending on the severity of the stimulation protocols used, these models may activate the neuroendocrine response to stress, but the contribution of these hormones to the final respiratory phenotype remains unknown.…”