Parental brain

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Maternal affection, by Edward Hodges Baily

Parental experience, as well as changing hormone levels during pregnancy and postpartum, cause changes in the parental brain.[1] Displaying maternal sensitivity towards infant cues, processing those cues and being motivated to engage socially with her infant and attend to the infant's needs in any context could be described as mothering behavior and is regulated by many systems in the maternal brain.[2] Research has shown that hormones such as oxytocin, prolactin, estradiol and progesterone are essential for the onset and the maintenance of maternal behavior in rats, and other mammals as well.[3][4][5][6][7][8] Mothering behavior has also been classified within the basic drives (sexual desire, hunger and thirst, fear, power/dominance etc.).[9] Less is known about the paternal brain, but changes in the father's brain occur alongside the mother once the offspring is born.[1]

Maternal brain[edit]

Maternal hormonal effect[edit]

Different hormone levels in the maternal brain and the overall well being of the mother account for 40%–50% of differences in the mother's attachment to her infant.[10] Mothers experience a decrease in estrogen and an increase in oxytocin and prolactin caused by lactation, pregnancy, parturition and interaction with the infant.[11]


The levels of oxytocin in the maternal brain correlate with maternal behaviors such as gazing, vocalization, positive affect, affectionate touch and other similar mother-infant relationship behaviors.[10]

Estradiol and progesterone[edit]

High mother-infant attachment correlates with a higher ratio of estradiol/progesterone at the end of pregnancy, than at the beginning.[10]


In the first few days after giving birth the levels of cortisol are high which correlates with maternal approach behavior and positive maternal attitudes.[12][13] Mothers with high levels of cortisol were also found to be more vocal towards their children.[12][13] Mothers who experienced adversity in their own childhood, had higher daily patterns of cortisol levels, and were less maternally sensitive.[14]


Glucocorticoids are not essential for displaying maternal behaviors, but in mothers, the levels of glucocorticoids are elevated as to initiate lactation.[15][16]


Different areas/structures of the brain are associated with different factors which contribute to maternal behavior. One's own infant acts as a special stimulus which triggers activation of different areas of the brain. These brain areas together allow for maternal behavior and related systems.[2]

The Medial Preoptic Area (MPOA) of the hypothalamus contains receptors for estradiol, progesterone, prolactin, oxytocin, vasopressin and opioids.[17] All these hormones are involved in some way in activating maternal behavior in the brain.[17] The following are other behavioral changes necessary for mothering that the MPOA is responsible for:[17]

Skin-to-skin contact with a newborn helps to increase the mother's oxytocin[18]

The amygdala and medial prefrontal cortex also contain receptors for the hormones which are most likely to be changing behavior at the time of pregnancy, and may be the sites where these changes occur.[17] Increased activity has also been observed in the amygdala as the mother is responding to emotions seen in negative (fearful) faces,[19] positive faces[20][21][22] or familiar faces[23] that her baby makes. Primate mothers with damage to the prefrontal cortex have also been associated with disrupted maternal behavior.[24]

The dorsolateral prefrontal cortex (DLPFC) plays a role in the attention, cognitive flexibility and working memory of the mother.[2] It helps the mother identify infant cues. In any environment and efficiently, it allows for the decision-making and action planning process involved in attending to the infant's cues.[2]

The thalamus, parietal cortex, and brain stem serve for processing the smell, touch and vocalization associated with the infant.[25]

Postpartum changes[edit]

Changes in estrogen, oxytocin and prolactin in the early postpartum period cause changes in the structures of the maternal brain.[26]

In animal mothers[edit]

Postpartum, new neuron production is suppressed due to decreased levels of estrogen and increased levels of glucocorticoids mother rats.[15][27] Mother-infant interaction is also thought to suppress neurogenesis in the hippocampus postpartum in the rat maternal brain.[15][27][28] Maternal experience increases neurogenesis in the subventricular zone (SBZ) which is responsible for producing the neurons of the olfactory bulb.[29] Prolactin is the hormone which mediates the increase in neurogenesis in SBZ.[29][30]

In animals, structures of the mother's brain change postpartum due to the increased interaction of the mother with the infant.[31]

The volume of gray matter increases postpartum in the following brain regions:[31]

These changes in the brain may occur in order to promote appropriate mothering behavior.[31] The mother's positive attitude towards the infant can be used as a predictor for the increase in gray matter in the above stated brain structures.[31]

Also in rats, the increased interaction with pups causes an increase in density in the MPOA.[32] Postpartum increase in gray matter volumes may help the mother activate the motivation to perform maternal behavior in response to cue from their offspring.[31]

Postpartum, the substantia nigra activates positive responses to the pup stimuli via dopamine neurons.[31]

In human mothers[edit]

The amygadala, prefrontal cortex and hypothalamus begin to change during pregnancy due to the high levels of stress experienced by the mother during this time.[33]

In human mothers there was a correlation between increased gray matter volume in the substantia nigra and positive emotional feelings towards the infant.[34][35]

Other changes such as menstrual cycle,[36] hydration, weight and nutrition[37][38] may also be factors which trigger the maternal brain to change during pregnancy and postpartum.

Maternal experience alters behaviors which stem from the hippocampus such as enhancing spatial navigation learning and behaviors linked with anxiety.[27]

Recent research has begun to look at how maternal psychopathology affects the maternal brain in relation to parenting. Daniel Schechter and colleagues have studied specifically interpersonal violence-related posttraumatic stress disorder (PTSD) and comorbid dissociation as associated with specific patterns of maternal neural activation in response to viewing silent video-stimuli of stressful parent-toddler interactions such as separation versus less-stressful ones such as play.[39][40] Importantly, less medial prefrontal cortex activity and greater limbic system activity (i.e. entorhinal cortex and hippocampus) were found among these post-traumatically stressed mothers of toddlers compared to mothers of toddlers without PTSD in response to stressful parent-child interactions as well as, within a different sample, in response to menacing adult male-female interactions. In the latter study, this pattern of corticolimbic dysregulation was linked to less observed maternal sensitivity during mother-child play.[41] Decreased ventral-medial prefrontal cortex activity in violence-exposed mothers, in response to viewing their own and unfamiliar toddlers in video-clips of separation versus play, has also been associated with increased PTSD symptoms, parenting stress and decreased methylation of the glucocorticoid receptor gene.[42]

Early experiences and shaping[edit]

Women who had a positive experience involving their family in their childhood are more likely to be more maternally sensitive and provide that same experience for their own children.[43] Mothers that had negative experiences involving their families undergo neurobiological changes which lead to high stress reactivity and insecure attachment. This causes lower maternal responsiveness to their infant's needs.[44][45]

Rat mothers provide high levels of maternal care (licking and grooming) to their offspring if they themselves received high maternal care as a pup from their own mothers.[46][47] Rat mothers who received low levels of maternal care as pups have lower levels of expression of the glucocorticoid receptor gene and lower synaptic density in the hippocampus.[48] In human mothers, lower hippocampal volume has been associated with a lower ability to regulate emotions and stress, which can be linked with decreased maternal sensitivity as a mother.[48][49][50] Mothers with insecure attachments to their own mothers display higher amygdala sensitivity to negative emotional stimuli, like hearing their infant cry.[51] Having more difficulty dealing with stress makes mothers less responsive to their infant's cues.[52]

Larger gray matter and increased activations of the following brain areas occur in mothers who had experienced higher quality maternal care as infants:[53]

This allows the mother to be more sensitive to her own infant's needs.[53]

Postpartum depression has also been associated with mothers who received low quality maternal care early in their own life.[54]

Paternal brain[edit]

In only 6% of mammalian species, including humans, the father plays a significant role in caring for his young.[55][56] Similar to the changes that occur in the maternal brain, the same areas of the brain (amygdala, hypothalamus, prefrontal cortex, olfactory bulb etc.) are activated in the father, and hormonal changes occur in the paternal brain to ensure display of parenting behavior.[1]

Paternal hormonal effect[edit]

An increase in levels of oxytocin, glucocorticoids, estrogen and prolactin occur in the paternal brain.[11][57] These hormonal changes occur through the father's interaction with the mother and his offspring.[1] Oxytocin levels are positively correlated with the amount of affection the father displays towards the child.[58] In humans, and in other primate species, lower levels of testosterone have been linked to the display of paternal behavior.[57][59]

In animal fathers[edit]

In father rats, just as in the mother rats, a decrease in neurogenesis in the hippocampus occurs postpartum.[60] Just like in mothers, fathers also have increased levels of glucocorticoids which are thought to suppress the production of new cells in the brain.[57]

Marmoset fathers have enhanced dendritic spine density in the prefrontal cortex. This increase correlates with increase in vasopressin receptors in this area of the paternal brain. With age, this effect is reversed, and is therefore believed to be driven by father-infant interactions.[1][61]

Changes in neurogenesis in the prefrontal cortex of the paternal brain have been linked in some species to recognition of kin.[62]

In human fathers[edit]

Being exposed to crying babies activates the prefrontal cortex and the amygdala in both fathers and mothers, but not in non-parents.[63][64] The level of testosterone in the paternal brain correlates with the effectiveness of the father's response to the baby's cry.[59] Increased levels of prolactin in the paternal brain has also been correlated with a more positive response to the infant's cry.[59]


  1. ^ a b c d e Leuner, B; Glasper, ER; Gould, E (Oct 2010). "Parenting and plasticity". Trends in Neurosciences. 33 (10): 465–73. doi:10.1016/j.tins.2010.07.003. PMC 3076301. PMID 20832872.
  2. ^ a b c d Barrett, Jennifer; Fleming, Alison S. (1 April 2011). "Annual Research Review: All mothers are not created equal: neural and psychobiological perspectives on mothering and the importance of individual differences". Journal of Child Psychology and Psychiatry. 52 (4): 368–397. doi:10.1111/j.1469-7610.2010.02306.x. PMID 20925656.
  3. ^ Bridges, R (2008). Neurobiology of the parental brain. Amsterdam: Academic.
  4. ^ Bridges, R.S (1990). Endocrine regulation of parental behavior in rodents, Mammalian parenting: Biochemical, neurobiological and behavioral determinants. New York: Oxford University Press. pp. 93–117.
  5. ^ Insel, T (1990). Oxytocin and maternal behavior, Mammalian parenting: biochemical, neurobiological and behavioral determinants. New York: Oxford University Press. pp. 260–280.
  6. ^ Numan, M (Jan 2007). "Motivational systems and the neural circuitry of maternal behavior in the rat". Developmental Psychobiology. 49 (1): 12–21. doi:10.1002/dev.20198. PMID 17186513.
  7. ^ Pryce C.R; Martin RD; Skuse D (1995). Motherhood in human and nonhuman primates. New York: Karger.
  8. ^ Rosenblatt, JS; Olufowobi, A; Siegel, HI (Apr 1998). "Effects of pregnancy hormones on maternal responsiveness, responsiveness to estrogen stimulation of maternal behavior, and the lordosis response to estrogen stimulation". Hormones and Behavior. 33 (2): 104–14. doi:10.1006/hbeh.1998.1441. PMID 9647936. S2CID 38510815.
  9. ^ Sewards, TV; Sewards, MA (Aug 2002). "Fear and power-dominance drive motivation: neural representations and pathways mediating sensory and mnemonic inputs, and outputs to premotor structures". Neuroscience and Biobehavioral Reviews. 26 (5): 553–79. doi:10.1016/S0149-7634(02)00020-9. PMID 12367590. S2CID 25374502.
  10. ^ a b c Fleming, AS; Ruble, D; Krieger, H; Wong, PY (Apr 1997). "Hormonal and experiential correlates of maternal responsiveness during pregnancy and the puerperium in human mothers". Hormones and Behavior. 31 (2): 145–58. doi:10.1006/hbeh.1997.1376. PMID 9154435. S2CID 2730009.
  11. ^ a b Numan, M; Insel, T (2003). The Neurobiology of Parental Behavior. Springer-Verlag.
  12. ^ a b Flemming, A.S; Steiner M; Andreson V (1987). "Hormonal and attitudinal correlates of maternal behavior during the early postparpregnancy". Journal of Reproductive and Infant Psychology. 5: 193–205. doi:10.1080/02646838708403495.
  13. ^ a b Corter, C; Flemming A.S (1990). Maternal responsiveness in humans: Emotional, cognitive and biological factors. Advances in the Study of Behavior. 19. pp. 83–136. doi:10.1016/s0065-3454(08)60201-6. ISBN 9780120045198.
  14. ^ Gonzalez, A; Jenkins, JM; Steiner, M; Fleming, AS (Jan 2009). "The relation between early life adversity, cortisol awakening response and diurnal salivary cortisol levels in postpartum women". Psychoneuroendocrinology. 34 (1): 76–86. doi:10.1016/j.psyneuen.2008.08.012. PMID 18835661. S2CID 12408292.
  15. ^ a b c Leuner, B; Mirescu, C; Noiman, L; Gould, E (2007). "Maternal experience inhibits the production of immature neurons in the hippocampus during the postpartum period through elevations in adrenal steroids". Hippocampus. 17 (6): 434–42. doi:10.1002/hipo.20278. PMID 17397044. S2CID 9900196.
  16. ^ Rees, SL; Panesar, S; Steiner, M; Fleming, AS (Mar 2006). "The effects of adrenalectomy and corticosterone replacement on induction of maternal behavior in the virgin female rat". Hormones and Behavior. 49 (3): 337–45. doi:10.1016/j.yhbeh.2005.08.012. PMID 16297919. S2CID 23974254.
  17. ^ a b c d Numan M; Fleming A.S; Levy F (2006). Maternal Behavior in Neill's physiology of reproduction. San Diego, CA: Elsevier. pp. 1921–1993.
  18. ^ Matthiesen, AS; Ransjö-Arvidson AB; Nissen E; Uvnäs-Moberg K. (2001). "Postpartum maternal oxytocin release by newborns: effects of infant hand massage and sucking". Birth. 28 (1): 13–9. doi:10.1046/j.1523-536x.2001.00013.x. PMID 11264623. Newborns placed skin-to-skin with their mothers to study maternal oxytocin release.
  19. ^ Gamer, M; Büchel, C (Jul 15, 2009). "Amygdala activation predicts gaze toward fearful eyes". The Journal of Neuroscience. 29 (28): 9123–6. doi:10.1523/JNEUROSCI.1883-09.2009. PMC 6665435. PMID 19605649.
  20. ^ Derntl, B; Habel, U; Windischberger, C; Robinson, S; Kryspin-Exner, I; Gur, RC; Moser, E (Aug 4, 2009). "General and specific responsiveness of the amygdala during explicit emotion recognition in females and males". BMC Neuroscience. 10: 91. doi:10.1186/1471-2202-10-91. PMC 2728725. PMID 19653893.
  21. ^ Killgore, WD; Yurgelun-Todd, DA (Apr 2004). "Activation of the amygdala and anterior cingulate during nonconscious processing of sad versus happy faces". NeuroImage. 21 (4): 1215–23. doi:10.1016/j.neuroimage.2003.12.033. PMID 15050549. S2CID 14190300.
  22. ^ Williams, MA; McGlone, F; Abbott, DF; Mattingley, JB (Jan 15, 2005). "Differential amygdala responses to happy and fearful facial expressions depend on selective attention". NeuroImage. 24 (2): 417–25. doi:10.1016/j.neuroimage.2004.08.017. PMID 15627583. S2CID 17638688.
  23. ^ Platek, SM; Kemp, SM (Feb 2009). "Is family special to the brain? An event-related fMRI study of familiar, familial, and self-face recognition". Neuropsychologia. 47 (3): 849–58. doi:10.1016/j.neuropsychologia.2008.12.027. PMID 19159636. S2CID 12674158.
  24. ^ Franzen, EA; Myers, RE (May 1973). "Neural control of social behavior: prefrontal and anterior temporal cortex". Neuropsychologia. 11 (2): 141–57. doi:10.1016/0028-3932(73)90002-x. PMID 4197348.
  25. ^ Xerri, C; Stern, JM; Merzenich, MM (Mar 1994). "Alterations of the cortical representation of the rat ventrum induced by nursing behavior". The Journal of Neuroscience. 14 (3 Pt 2): 1710–21. doi:10.1523/JNEUROSCI.14-03-01710.1994. PMC 6577528. PMID 8126565.
  26. ^ Rosenblatt, J.S (2002). Handbook of parenting. Mahwah, NJ: Erlbaum. pp. 31–60.
  27. ^ a b c Darnaudéry M, Perez-Martin M, Del Favero F, Gomez-Roldan C, Garcia-Segura LM, Maccari S (Aug 2007). "Early motherhood in rats is associated with a modification of hippocampal function". Psychoneuroendocrinology. 32 (7): 803–12. doi:10.1016/j.psyneuen.2007.05.012. hdl:10261/71909. PMID 17640823. S2CID 33878419.
  28. ^ Pawluski, JL; Galea, LA (Oct 12, 2007). "Reproductive experience alters hippocampal neurogenesis during the postpartum period in the dam". Neuroscience. 149 (1): 53–67. doi:10.1016/j.neuroscience.2007.07.031. PMID 17869008. S2CID 46107114.
  29. ^ a b Shingo, T; Gregg, C; Enwere, E; Fujikawa, H; Hassam, R; Geary, C; Cross, JC; Weiss, S (Jan 3, 2003). "Pregnancy-stimulated neurogenesis in the adult female forebrain mediated by prolactin". Science. 299 (5603): 117–20. Bibcode:2003Sci...299..117S. doi:10.1126/science.1076647. PMID 12511652. S2CID 38577726.
  30. ^ Furuta, M; Bridges, RS (Apr 21, 2005). "Gestation-induced cell proliferation in the rat brain". Brain Research. Developmental Brain Research. 156 (1): 61–6. doi:10.1016/j.devbrainres.2005.01.008. PMID 15862628.
  31. ^ a b c d e f Kim, Pilyoung; Leckman, James F.; Mayes, Linda C.; Feldman, Ruth; Wang, Xin; Swain, James E. (1 January 2010). "The plasticity of human maternal brain: Longitudinal changes in brain anatomy during the early postpartum period". Behavioral Neuroscience. 124 (5): 695–700. doi:10.1037/a0020884. PMC 4318549. PMID 20939669.
  32. ^ Featherstone, RE; Fleming, AS; Ivy, GO (Feb 2000). "Plasticity in the maternal circuit: effects of experience and partum condition on brain astrocyte number in female rats". Behavioral Neuroscience. 114 (1): 158–72. doi:10.1037/0735-7044.114.1.158. PMID 10718271.
  33. ^ McEwen, BS (Jul 2007). "Physiology and neurobiology of stress and adaptation: central role of the brain". Physiological Reviews. 87 (3): 873–904. doi:10.1152/physrev.00041.2006. PMID 17615391.
  34. ^ Bartels, A; Zeki, S (Mar 2004). "The neural correlates of maternal and romantic love". NeuroImage. 21 (3): 1155–66. CiteSeerX doi:10.1016/j.neuroimage.2003.11.003. PMID 15006682. S2CID 15237043.
  35. ^ Noriuchi, M; Kikuchi, Y; Senoo, A (Feb 15, 2008). "The functional neuroanatomy of maternal love: mother's response to infant's attachment behaviors". Biological Psychiatry. 63 (4): 415–23. doi:10.1016/j.biopsych.2007.05.018. PMID 17686467. S2CID 790201.
  36. ^ Protopopescu, X; Butler, T; Pan, H; Root, J; Altemus, M; Polanecsky, M; McEwen, B; Silbersweig, D; Stern, E (2008). "Hippocampal structural changes across the menstrual cycle". Hippocampus. 18 (10): 985–8. doi:10.1002/hipo.20468. PMID 18767068. S2CID 5144570.
  37. ^ Castro-Fornieles, J; Bargalló, N; Lázaro, L; Andrés, S; Falcon, C; Plana, MT; Junqué, C (Jan 2009). "A cross-sectional and follow-up voxel-based morphometric MRI study in adolescent anorexia nervosa". Journal of Psychiatric Research. 43 (3): 331–40. doi:10.1016/j.jpsychires.2008.03.013. PMID 18486147.
  38. ^ Raji, CA; Ho, AJ; Parikshak, NN; Becker, JT; Lopez, OL; Kuller, LH; Hua, X; Leow, AD; Toga, AW; Thompson, PM (Mar 2010). "Brain structure and obesity". Human Brain Mapping. 31 (3): 353–64. doi:10.1002/hbm.20870. PMC 2826530. PMID 19662657.
  39. ^ Schechter, DS; Moser, D; Wang, Z; Marsh, R; Hao, XJ; Duan, Y; Yu, S; Gunter, B; Murphy, D; McCaw, J; Kangarlu, A; Willheim, E; Myers, M; Hofer, M; Peterson, BS (2012). "An fMRI study of the brain responses of traumatized mothers to viewing their toddlers during separation and play". Journal of Social Cognitive and Affective Neuroscience. 7 (8): 969–79. doi:10.1093/scan/nsr069. PMC 3501701. PMID 22021653.
  40. ^ Moser, DA; Aue, T; Wang, Z; Rusconi-Serpa, S; Favez, N.; Peterson, BS; Schechter, DS (2014). "Comorbid dissociation dampens limbic activation in violence-exposed mothers with PTSD who are exposed to video-clips of their child during separation". Stress. 16 (5): 493–50. doi:10.3109/10253890.2013.816280. PMID 23777332. S2CID 34731243.
  41. ^ Moser, DA; Aue, T; Favez, N; Kutlikova, H; Suardi, F; Cordero, MI; Rusconi Serpa, S; Schechter, DS. "Violence-related PTSD and neural activation when seeing emotional male-female interactions". Social Cognitive and Affective Neuroscience.
  42. ^ Schechter, DS; Moser, DA; Paoloni-Giacobino, A; Stenz, A; Gex-Fabry, M; Aue, T; Adouan, W; Cordero, MI; Suardi, F; Manini, A; Sancho Rossignol, A; Merminod, G; Ansermet, F; Dayer, AG; Rusconi Serpa, S (2015). "Methylation of NR3C1 is related to maternal PTSD, parenting stress and maternal medial prefrontal cortical activity in response to child separation among mothers with histories of violence exposure". Frontiers in Psychology. 6: 690. doi:10.3389/fpsyg.2015.00690. PMC 4447998. PMID 26074844.[permanent dead link]
  43. ^ Belsky, J; Jaffee, SR; Sligo, J; Woodward, L; Silva, PA (Mar–Apr 2005). "Intergenerational transmission of warm-sensitive-stimulating parenting: a prospective study of mothers and fathers of 3-year-olds". Child Development. 76 (2): 384–96. doi:10.1111/j.1467-8624.2005.00852.x. PMID 15784089.
  44. ^ Belsky, J (2005). The developmental and evolutionary psychology of intergenerational transmission of attachment in Attachment and bonding: A new synthesis. Cambridge, MA: MIT Press. pp. 169–198.
  45. ^ Meaney, MJ (2001). "Maternal care, gene expression, and the transmission of individual differences in stress reactivity across generations". Annual Review of Neuroscience. 24: 1161–92. doi:10.1146/annurev.neuro.24.1.1161. PMID 11520931.
  46. ^ Francis, D; Diorio, J; Liu, D; Meaney, MJ (Nov 5, 1999). "Nongenomic transmission across generations of maternal behavior and stress responses in the rat". Science. 286 (5442): 1155–8. doi:10.1126/science.286.5442.1155. PMID 10550053.
  47. ^ Francis, DD; Young, LJ; Meaney, MJ; Insel, TR (May 2002). "Naturally occurring differences in maternal care are associated with the expression of oxytocin and vasopressin (V1a) receptors: gender differences". Journal of Neuroendocrinology. 14 (5): 349–53. CiteSeerX doi:10.1046/j.0007-1331.2002.00776.x. PMID 12000539. S2CID 16005801.
  48. ^ a b Kaffman, A; Meaney, MJ (Mar–Apr 2007). "Neurodevelopmental sequelae of postnatal maternal care in rodents: clinical and research implications of molecular insights". Journal of Child Psychology and Psychiatry, and Allied Disciplines. 48 (3–4): 224–44. doi:10.1111/j.1469-7610.2007.01730.x. PMID 17355397.
  49. ^ Bredy, TW; Grant, RJ; Champagne, DL; Meaney, MJ (Nov 2003). "Maternal care influences neuronal survival in the hippocampus of the rat". The European Journal of Neuroscience. 18 (10): 2903–9. doi:10.1111/j.1460-9568.2003.02965.x. PMID 14656341. S2CID 20323905.
  50. ^ Heim, C; Nemeroff, CB (Jan 2009). "Neurobiology of posttraumatic stress disorder". CNS Spectrums. 14 (1 Suppl 1): 13–24. PMID 19169190.
  51. ^ Lemche, E; Giampietro, VP; Surguladze, SA; Amaro, EJ; Andrew, CM; Williams, SC; Brammer, MJ; Lawrence, N; Maier, MA; Russell, TA; Simmons, A; Ecker, C; Joraschky, P; Phillips, ML (Aug 2006). "Human attachment security is mediated by the amygdala: evidence from combined fMRI and psychophysiological measures". Human Brain Mapping. 27 (8): 623–35. doi:10.1002/hbm.20206. PMC 6871466. PMID 16284946.
  52. ^ Martorell, GA; Bugental, DB (Dec 2006). "Maternal variations in stress reactivity: implications for harsh parenting practices with very young children". Journal of Family Psychology. 20 (4): 641–7. doi:10.1037/0893-3200.20.4.641. PMID 17176199.
  53. ^ a b Kim, Pilyoung; Leckman, James F.; Mayes, Linda C.; Newman, Michal-Ann; Feldman, Ruth; Swain, James E. (30 September 2009). "Perceived quality of maternal care in childhood and structure and function of mothers' brain". Developmental Science. 13 (4): 662–673. doi:10.1111/j.1467-7687.2009.00923.x. PMC 3974609. PMID 20590729.
  54. ^ Mayes, L.C; Leckman, J.F (2007). "Parental representation and subclinical changes in postpartum mood". Infant Mental Health Journal. 28 (3): 281–295. doi:10.1002/imhj.20136. PMID 28640466.
  55. ^ Lonstein, JS; De Vries, GJ (Aug 2000). "Sex differences in the parental behavior of rodents". Neuroscience and Biobehavioral Reviews. 24 (6): 669–86. doi:10.1016/S0149-7634(00)00036-1. PMID 10940441. S2CID 11751600.
  56. ^ Fernandez-Duque, E; et al. (2009). "The biology of paternal care in human and non-human primates". Annu. Rev. Anthropol. 38: 115–130. doi:10.1146/annurev-anthro-091908-164334.
  57. ^ a b c Wynne-Edwards, KE (Sep 2001). "Hormonal changes in mammalian fathers". Hormones and Behavior. 40 (2): 139–45. doi:10.1006/hbeh.2001.1699. PMID 11534974. S2CID 36193536.
  58. ^ Feldman, R; Gordon, I; Schneiderman, I; Weisman, O; Zagoory-Sharon, O (Sep 2010). "Natural variations in maternal and paternal care are associated with systematic changes in oxytocin following parent-infant contact". Psychoneuroendocrinology. 35 (8): 1133–41. doi:10.1016/j.psyneuen.2010.01.013. PMID 20153585. S2CID 23925657.
  59. ^ a b c Fleming, AS; Corter, C; Stallings, J; Steiner, M (Dec 2002). "Testosterone and prolactin are associated with emotional responses to infant cries in new fathers". Hormones and Behavior. 42 (4): 399–413. doi:10.1006/hbeh.2002.1840. PMID 12488107. S2CID 9172039.
  60. ^ Kozorovitskiy, Y; et al. (2007). "Fatherhood influences neurogenesis in the hippocampus of California mice". Society for Neuroscience. 21: 626.
  61. ^ Kozorovitskiy, Y; Hughes, M; Lee, K; Gould, E (Sep 2006). "Fatherhood affects dendritic spines and vasopressin V1a receptors in the primate prefrontal cortex". Nature Neuroscience. 9 (9): 1094–5. doi:10.1038/nn1753. PMID 16921371. S2CID 11852516.
  62. ^ Mak, GK; Weiss, S (Jun 2010). "Paternal recognition of adult offspring mediated by newly generated CNS neurons". Nature Neuroscience. 13 (6): 753–8. doi:10.1038/nn.2550. PMID 20453850. S2CID 205433066.
  63. ^ Seifritz E, Esposito F, Neuhoff JG, Lüthi A, Mustovic H, Dammann G, von Bardeleben U, Radue EW, Cirillo S, Tedeschi G, Di Salle F (Dec 15, 2003). "Differential sex-independent amygdala response to infant crying and laughing in parents versus nonparents". Biological Psychiatry. 54 (12): 1367–75. doi:10.1016/s0006-3223(03)00697-8. PMID 14675800. S2CID 12644453.
  64. ^ Swain, JE; Lorberbaum, JP; Kose, S; Strathearn, L (Mar–Apr 2007). "Brain basis of early parent-infant interactions: psychology, physiology, and in vivo functional neuroimaging studies". Journal of Child Psychology and Psychiatry, and Allied Disciplines. 48 (3–4): 262–87. doi:10.1111/j.1469-7610.2007.01731.x. PMC 4318551. PMID 17355399.