Neurotrophins and acupuncture

The aim of this review is to report recent findings and ongoing studies on the effects of acupuncture on endogenous biological mediators, in particular on neurotrophins such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). Acupuncture is a therapeutic technique and is a part of Traditional Chinese Medicine (TCM). Western descriptions of the clinical efficacy of acupuncture on pain, inflammation, motor dysfunction, mood disorders, and seizures are based on the stimulation of several classes of sensory afferent fibers and the consequent activation of physiological processes similar to those resulting from physical exercise or deep massage. The established research on the neuro-physiological correlates of acupuncture has pointed towards endogenous opioids as the principal biological mediators of the therapeutic actions of this ancient technique. More recently, several classes of molecules, such as neurotransmitters, cytokines and growth factors, have also been identified as possible mediators for specific acupuncture effects. This review will focus on the links between acupuncture and a class of growth factors known as neurotrophins (NTs), which are the main mediators of neural activity, plasticity and repair following neurodegeneration and/or traumatic injury. A special emphasis will be placed on the work of our laboratory investigating the role of nerve growth factor (NGF), the prototypical member of the neurotrophin family, as a mediator of acupuncture effects in the central nervous system (CNS) and as a modulator of sensory and autonomic activity.