Toxins have played a crucial role in the identification, isolation and purification of receptors and ion channels, when most of the presently well-known receptors have not yet been cloned. The appropriately labeled toxins (radioactive, fluorescent etc.) provided information about receptor localization in organisms as well as providing the first hints about the nature of receptor binding sites: the presence of positively or negatively charged amino acid residues, or high or low hydrophobicity etc. Recent progress in the elucidation of the receptor and ion channel mechanisms of action is due to the achievements of the X-ray crystallography and cryo-electron microscopy performed on them in different states. Additionally, high resolution data on toxin complexes with the receptors or with their models is also available. Information on the sites involved in the binding of toxins provides the basis for drug design. In addition, in relatively rare cases, the toxins can become the drugs themselves.

The task of this collection is to present different classes of toxins which specifically target diverse ion channels, with a special emphasis on their chemical and three-dimensional structure.

The reviews and experimental papers will cover various peptide and protein neurotoxins, as well as low molecular weight compounds. The words “ion channels” in the title indicate that various kinds of ion channels are embraced, including the ligand-gated ones and voltage-dependent channels. Although the word “receptor” is also included, the reason is that many ion channels play the role of the receptors, but receptors not having an ion–channel function, for example such as GPCRs will be mentioned only briefly.

We welcome submissions including, but not limited to, the following areas –

I. Three-finger toxins acting on the Cys-loop receptors.
II. Three-finger toxins non targeting ion channels
III. Three-finger mammalian Ly6 proteins affecting assembly and functions of nicotinic acetylcholine receptors.
IV. Conotoxins acting on nicotinic acetylcholine receptors and other ligand-gated ion channels
V. Chemical synthesis of naturally occurring peptide and protein neurotoxins, design and synthesis of their analogs
VI. Spatial structure of ligand-gated ion channels, their domains and models in complexes with neurotoxins
VII. Peptide and protein neurotoxins acting on voltage-gated ion channels
VIII. Low-molecular weight neurotoxins acting on the ligand-gated and voltage-gated ion channels.
IX. From naturally-occurring neurotoxins to drugs

Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.