ReviewEvolutionary functions of early social modulation of hypothalamic-pituitary-adrenal axis development in humans
Section snippets
Evolutionary paradox of psychosocial stress
Psychosocial challenges reliably stimulate the hypothalamic-pituitary-adrenal axis (HPAA) in humans and many other mammals (Hennessey et al., 2009, Yim et al., 2010). Given the apparent short- and long-term costs of HPAA activation to physical and mental health (Cohen, 2004, Kiecolt-Glaser et al., 2010, Shonkoff et al., 2009), this presents an evolutionary paradox: Why do social interactions and relationships affect HPAA responses? Currently no satisfactory explanations exist for why natural
Physiological mechanisms, developmental plasticity and adaptive function
Most studies of social modulation of early HPAA development have been based on clinical, epidemiological and experimental (primarily nonhuman animal model) research paradigms. Tremendous advances have been made in understanding the physiological, neurobiological and genetic mechanisms that underpin stress responses (de Kloet et al., 2005b, Joëls and Baram, 2009, Lupien et al., 2009, McEwen, 2007, Sapolsky et al., 2000, Weaver et al., 2004). Explanations for early social modulation of HPAA
Stress in the wild: HPAA responses in natural, everyday context
“What is missing are long term prospective studies that track the nature and timing of early stress exposure and the linkages to children's later stress exposure, HPA functioning, and behaviors” (Essex et al., 2002, p. 777).
Investigating relations among HPAA responses, neural remodeling and cognitive adaptations to the social environment is not a simple or easy task (e.g., Pine et al., 2001). While cortisol can affect cognitive functioning and emotional states, cognitive processing and
Concluding remarks
Returning to the paradox of why natural selection favored sensitivity of stress response to social stimuli in the human child, several points emerge. Human childhood is a life history stage that appears necessary and useful for acquiring the information and practice to build and refine mental algorithms critical for negotiating the social coalitions that are key to success in our species. Mastering the social environment presents special challenges for the human child. Results from the
Acknowledgements
Our research efforts have primarily been funded by NSF BCS-SBE-0640442, SBR-0136023, SBR-9205373, & BNS-8920569 (MVF, MPM, DP), and Simon Fraser University – President's Research Start Up Grant (PAN) and CIHR Operating Grant # 106705. We thank Dr. Katrina Salvante for her assistance with figure 2 and Dr. Robert Walker for help with figure 4.
References (402)
- et al.
Do early-life events permanently alter behavioral and hormonal response to stressors?
Int. J. Dev. Neurosci.
(1998) - et al.
Preimplantation urinary hormone profiles and the probability of conception in healthy women
Fertil. Steril.
(1999) - et al.
Multiple courses of antenatal corticosteroids and outcome of premature neonates. North American Thyrotropin-Releasing Hormone Study Group
Am. J. Obstet. Gynecol.
(1999) Social stress, immune functions and disease in rodents
Front. Neuroendocrinol.
(2007)- et al.
Social factors and individual vulnerability to chronic stress exposure
Neurosci. Biobehav. Rev.
(2005) - et al.
Glucocorticoids are necessary for enhancing the acquisition of associative memories after acute stressful experience
Horm. Behav.
(2003) Mother knows best: epigenetic inheritance, maternal effects, and the evolution of human intelligence
Dev. Rev.
(2006)- et al.
Social cognitive neuroscience: where are we heading?
Trends Cogn. Neurosci.
(2004) - et al.
Antenatal dexamethasone and decreased birth weight
Obstet. Gynecol.
(2001) - et al.
Plasma DHEA levels in wild, territorial red squirrels: seasonal variation and effect of ACTH
Gen. Comp. Endocrinol.
(2008)