Evidence of Nicotine-Induced, Curare-Insensitive, Behavior in Planarians.

Planarians are rapidly developing into very useful research subjects in pharmacology and neuroscience research. Here we report that curare, a cholinergic nicotinic receptor antagonist, alleviates the nicotine-induced planarian seizure-like movements (pSLM) by up to 50 % at equimolar concentrations of nicotine and curare (1 mM), while curare alone does not induce significant pSLMs. The simplest interpretation of our data is that there are nicotine induced behaviors insensitive to curare in our experimental organism. To the best of our knowledge, this is the first report on curare-insensitive, nicotine-induced effects in any organism.