The messengers from peripheral nervous system to central nervous system: involve

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Zhen Ci Yan Jiu. 2008 Feb;33(1):37-40.

The messengers from peripheral nervous system to central nervous

system: involvement of neurotrophins and cytokines in the mechanisms

of acupuncture

Du J.

National Institute of Mental Health, Bethesda, MD 20892-1381, USA.

Neurotrophic factors and cytokines are involved in the regulation of

neuronal survival, axonal myelination, and synaptic plasticity in

both central nervous system (CNS) and peripheral nervous system

(PNS). The members of the neurotrophic factor family include nerve

growth factor (NGF), brain derived neurotrophic factor (BDNF),

neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5).

These molecules bind to two types of receptors: (1) tyrosine kinase

receptors (TrkA, TrkB, TrkC) and 2) common neurotrophin receptor (p

75 NTR). The internalization and retrograde axonal transport of

neurotrophin receptors are important for their signal transduction

supporting neuronal survival, synaptic plasticity, and axonal

myelination.

In addition, a growing body of data suggests that neurotrophins are

involved in the pathophysiologicl courses of inflammatory pain,

neurodegenerative disease, and psychiatric diseases.

Cytokines, including IL-1, IL-2, IL-6, and TNF-alpha,are important

mediators of the immune response and play a key role in the diseases

by acting on inflammatory immune cells, neuronal cells, muscle cells,

and vessel cells. Interestingly, some cytokines (e.g. TNF-alpha, IL-

2, TGF-beta) are also able to regulate synaptic plasticity and affect

CNS functions. The neurotrophins and cytokines release in response to

various stimuli, such as electronic stimulation, or inflammation.

This crosstalk from PNS to CNS is involved in the pathophysiology of

many human diseases and may contribute to the effects of acupuncture.

Based on our knowledge to neurotrophins and cytokines, we proposed

the neurotrophin/cytokine hypothesis for the mechanism of

acupuncture. This hypothesis may initiate the discussion on the

possible roles of neurotrophins/cytokines in the therapeutic effects

of acupuncture and shed light to the discovery of mechanism of

acupuncture in the treatment of devastating diseases.