These mechanisms may interact with brain pathways involved in acquisition of opioid dependence, such as those using N-methyl D-aspartate receptors46, muscarinic receptors47, corticotropin releasing factor (CRF) receptor CRF148, tachykinin receptors49, voltage-gated Ca2+-channels50, opioid receptor phosphorylation51, oxidative stress52, and nitric oxide-cGMP cascades53. Here, CRH is linked to opiate dependence.