Herbal Remedy

RESEARCH HIGHLIGHTS

File name: NRN0305_JQ2_HL Word count: 419 Accompanying picture: YES ADDICTION File name of picture: Herbal remedy

Ibogaine, which is derived from an gic region that includes the VTA. This study shows a direct link African shrub, has long been thought As dopamine is the key neuro- between GDNF and ibogaine’s desir- to help alcoholics and drug addicts to transmitter that is consistently associ- able effect on alcohol addiction. kick the habit, but its side effects, such ated with reward, the authors used a Therefore, the development of agents as hallucinations, have kept it off dopaminergic neuroblastoma cell line that activate the GDNF pathway pharmacy shelves. Now, a new study to study the downstream signalling might be useful for treating drug and has identified a molecular pathway events that are activated by ibogaine. alcohol abuse. that is responsible for ibogaine’s anti- Ibogaine induces an increase in Jane Qiu addiction effects, which might open GDNF mRNA expression, which References and links leads to increased secretion of GDNF ORIGINAL RESEARCH PAPER He, D. Y. et al. the door for the development of Glial cell line-derived neurotrophic factor mediates other drugs to reverse addiction with- and activation of downstream sig- the desirable actions of the anti-addiction drug out undesirable side effects. nalling molecules such as mitogen- ibogaine against alcohol consumption. J. Neurosci. 25, 619–628 (2005) Reporting in the Journal of activated protein kinases. FURTHER READING Airaksinen, M. S. & Neuroscience,He and colleagues Importantly, injection of GDNF into Saarma, M. The GDNF family: signalling, biological found that systemic administration of the VTA also reduces alcohol intake functions and therapeutic value. Nature Rev. Neurosci. 4, 383–394 (2003) ibogaine decreased alcohol consump- in rats, and anti-GDNF neutralizing WEB SITE tion in rats that had been trained to antibodies markedly attenuate the Ron’s laboratory: http://www.egcrc.org/pis/ron- drink alcohol voluntarily. The treat- effect of ibogaine on alcohol con- c.htm ment was also effective in a relapse sumption. model, in which rats were re-exposed to alcohol after a period of absti- nence. As the ventral tegmental area (VTA) is one of the main brain regions in the ‘reward’ circuitry that is altered in alcohol addicts, the authors injected ibogaine into this part of the rat brain and found that this also kept alcohol consumption at bay. But how does ibogaine interfere with the rewarding effects of alcohol? Previous research has shown that chronic cocaine or morphine administration results in decreased activity of the glial cell line-derived neurotrophic factor (GDNF) pathway in rats, and that injection of GDNF into the VTA can block the behavioural effects of these drugs. In this study, systemic ibogaine administration increased the expression of GDNF mRNA in the midbrain dopaminer-