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From tenyears ago, no less....

1: Mol Psychiatry. 2000 Jan;5(1):14-21.

The role of stress in the pathophysiology of the dopaminergic system.

Pani L, Porcella A, Gessa GL.

CNR Center for Neuropharmacology and 'BB Brodie' Department of Neuroscience,
University of Cagliari, Cagliari, Italy. panil@unica.it

In this review, we will examine the most recent preclinical evidence in support
of the fact that both acute and chronic stress may have a detrimental impact on
the normal function of the dopaminergic system. In recent decades, the term
stress has changed its meaning from that of a 'non-specific body response' to a
'monitoring system of internal and external cues'; that is a modality of reaction
of the mammalian central nervous system (CNS) which is critical to the adaptation
of the organism to its environment. Compelling results have demonstrated that the
dopaminergic system is important not only for hedonic impact or reward learning
but also, in a broader sense, for reactivity to perturbation in environmental
conditions, for selective information processing, and for general emotional
responses, which are essential functions in the ability (or failure) to cope with
the external world. In this, stress directly influences several basic behaviors
which are mediated by the dopaminergic system such as locomotor activity, sexual
activity, appetite, and cross sensitization with drugs of abuse. Studies using
rat lines which are genetically different in dopamine (DA) physiology, have shown
that even small alterations in the birth procedure or early life stress events
may contribute to the pathophysiology of psychiatric disorders-in particular
those involving central DA dysfunction-and may cause depression or psychotic
derangement in the offspring. Finally, the fact that the dopaminergic system
after stress responds, preferentially, in the medial prefrontal cortex (MFC), is
thought to serve, in humans, as a protection against positive psychotic symptoms,
since the increased DA activity in the MFC suppresses limbic DA transmission.
However, excessive MFC dopaminergic activity has a negative impact on the
cognitive functions of primates, making them unable to select and process
significant environmental stimuli. Thus it appears that a critical range of DA
turnover is necessary for optimal cognitive functioning after stress, in the
response of the CNS to ever-changing environmental demands. Molecular Psychiatry
(2000) 5, 14-21.


PMID: 10673764 [PubMed - indexed for MEDLINE]

Full Text at http://www.nature.com/mp/journal/v5/.../4000589a.html