Basic Research Studies > Cellular
Mechanisms of Addictive Processes
Cellular Mechanisms of Addictive
Processes
Opioid modulation of the coeruleo-cortical pathway
(NIH/NIDA)

Schematic diagram showing potential ways in which opiates sensitize
LC neurons to CRF. Left: LC neurons without morphine. Middle:
Chronic morphine may increase second-messenger response to
CRF. Right: chronic morphine might reduce internalization
of CRF receptors. |
Goal: To examine cellular interactions between opioids and
the stress-related peptide corticotropin releasing factor
in the noradrenergic nucleus locus coeruleus.
The interaction between the stress axis and endogenous opioid
systems has gained substantial clinical interest as it is
increasingly recognized that stress predisposes to opiate
abuse. For example, stress has been implicated as a risk
factor in vulnerability to the initiation and maintenance
of opiate abuse and is thought to play an important role
in relapse in subjects with a history of abuse. However,
the impact of stress-opioid interactions extends beyond vulnerability
to opiate abuse.
Numerous reports indicating that stress alters individual
sensitivity to opiates suggest that prior stress can influence
the pharmacodynamics of opiates that are used in clinical
settings. Conversely, the effects of opiates on different
components of the stress axis can impact on individual responsivity
to stressors and potentially predispose individuals to stress-related
psychiatric disorders. Because these interactions have potentially
widespread clinical consequences, it is important to identify
substrates of the stress response and endogenous opioid systems
that interact and the specific points at which stress circuits
and endogenous opioid systems intersect.
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