Vasopressin and oxytocin release within the brain: a dynamic concept of multiple and variable modes of neuropeptide communication

Oxytocin pathways in the intergenerational transmission of maternal early life stress

“…The most prominent peripheral OT effects via the classical hypothalamic-neurohypophyseal pathway are the induction of parturition through increased contractibility of the uterine smooth muscles and milk ejection from the mammary gland in response to suckling stimuli in lactating females (Lee et al, 2009). In the central nervous system (CNS), however, OT’s communication pathways are more complex (Knobloch et al, 2012; Landgraf and Neumann, 2004) and still subject to investigation. There are two proposed mechanisms through which OT neurons in the hypothalamus communicate with extrahypothalamic neurons and brain structures.…”

“…First, it has been suggested that there is a slow, “unwired”, and global transmission of OT that is released mainly from neuronal dendrites, but also from axons and soma in the hypothalamus to reach extrahypothalamic brain structures, such as the amygdala or the cingulate cortex (Boccia et al, 2013). This diffuse mode of communication, referred to as volume transmission (Landgraf and Neumann, 2004; Ludwig and Leng, 2006), enables OT to act as a neuromodulator within the brain and implies a slow enzymatic degradation of OT, which in turn permits OT to travel long distances (Landgraf and Neumann, 2004). Second, it has been shown that in the rodent (Knobloch et al, 2012) and human brain (Boccia et al, 2013) there is a variety of “hard-wired” oxytocinergic nerve fibers from the hypothalamus to limbic, mesencephalic, and cortical brain regions that allow fine-tuned and fast modulation of target structures (Knobloch et al, 2012; Landgraf and Neumann, 2004; Stoop, 2012; Strathearn, 2011).…”

“…This diffuse mode of communication, referred to as volume transmission (Landgraf and Neumann, 2004; Ludwig and Leng, 2006), enables OT to act as a neuromodulator within the brain and implies a slow enzymatic degradation of OT, which in turn permits OT to travel long distances (Landgraf and Neumann, 2004). Second, it has been shown that in the rodent (Knobloch et al, 2012) and human brain (Boccia et al, 2013) there is a variety of “hard-wired” oxytocinergic nerve fibers from the hypothalamus to limbic, mesencephalic, and cortical brain regions that allow fine-tuned and fast modulation of target structures (Knobloch et al, 2012; Landgraf and Neumann, 2004; Stoop, 2012; Strathearn, 2011). Effects of OT in the CNS and in the periphery (e.g., heart and cardiovascular system, kidney, reproductive organs) are critically dependent on presence of OT receptors (OTR) (Gimpl and Fahrenholz, 2001).…”

Pilot study demonstrates that salivary oxytocin can be measured unobtrusively in preterm infants

“…This means that a presumably important biological factor for social interactions, salivary oxytocin, could be investigated during Kangaroo care in a trial with a determined required sample size of 21 vials. However, there has been a controversy in the literature about the existence of a direct relationship between such peripheral oxytocin concentrations and central oxytocin concentrations 20, 21.…”

“…Once released into the brain, the large oxytocin molecules do not cross the blood–brain barrier easily 20. Indeed, several studies demonstrated no correlation between central and peripheral oxytocin 17, 23.…”