"The
neurobiology of pleasure, reward processes, addiction and
their health implications" by Tobias Esch
and George B. Stefano is in the August issue of NEL
(Vol. 25 No.4, 2004).
Modern
science begins to understand pleasure as a potential component
of salutogenesis. Thereby, pleasure is described as a state
or feeling of happiness and satisfaction resulting from an
experience that one enjoys. The authors examine the neurobiological
factors underlying reward processes and pleasure phenomena.
Further,
health implications related to pleasurable activities are
analyzed. With regard to possible negative effects of pleasure,
we focus on addiction and motivational toxicity. Pleasure
can serve cognition, productivity and health, but simultaneously
promotes addiction and other negative behaviors, i.e., motivational
toxicity.
It
is a complex neurobiological phenomenon, relying on reward
circuitry or limbic activity. These processes involve dopaminergic
signaling. Moreover, endorphin and endogenous morphinergic
mechanisms may play a role. Natural rewarding activities are
necessary for survival and appetitive motivation, usually
governing beneficial biological behaviors like eating, sex
and reproduction. Social contacts can further facilitate the
positive effects exerted by pleasurable experiences. However,
artificial stimulants can be detrimental, since flexibility
and normal control of behavior are deteriorated. Additionally,
addictive drugs are capable of directly acting on reward pathways.
Thus,
the concrete outcome of pleasant experiences may be a question
of dose. Moderate pleasurable experiences are able to enhance
biological flexibility and health. Hence, pleasure can be
a resistance resource or may serve salutogenesis. Natural
rewards are mediated by sensory organ stimulation, thereby
exhibiting a potential association with complementary medical
approaches. Trust and belief can be part of a self-healing
potential connected with rewarding stimuli given limbic involvement.
Further,
the placebo response physiologically resembles pleasure phenomena,
since both involve brain's reward circuitry stimulation and
subjective feelings of well-being. Pleasurable activities
can stimulate personal growth and may help to induce healthy
behavioral changes, including stress management.
However,
more research is needed to better understand the nature, neurobiology
and maybe dangerous aspects of pleasure. Also, a possible
involvement of endogenous morphinergic signaling has to be
studied further given its limbic presence and recent report
demonstrating that this signal molecule can be made in ganglionic
tissues (Zhu et al., 2004). [Press
Release]
Zhu
W, Mantione KJ, Stefano GB. Reticuline
exposure to invertebrate ganglia increases endogenous morphine
levels. Neuroendocrinology Letters. 2004. Oct. in press.
Full
text published in the August issue,
Vol. 25 No.4, 2004
Neuroendocrinology
Letters
www.nel.edu
