Ion channels are targets of numerous classes of drugs (antidepressive, antidiabetic, antiepileptic, antiarrythmic, etc ...). It now appears that newly discovered channels with newly discovered functions are excellent candidates for finding new molecules active in psychiatric diseases, in neuroprotection or against pain. The presentation will mainly deal with two families of ionic channels. The first one is the 2 pore domain family of K⁺ channels (K_2P), a family with a very important physiological function since it comprises the background channels i.e. channels that impose the resting potentials in most cells and are regulated by many neurotransmitters acting on metabotropic receptors coupled to Gs, Gi and Gq processes. It comprises an important class of mechanosensitive K⁺ channels that will be discussed in some details for its structural and functional aspects and for its regulation. This later class of K⁺ channels plays a central role in lipid sensing, in pain associated with mechanical sensing, osmo-sensing, temperature sensing (both warm and cold), in the action of volatile anesthetics and in neuroprotection provided by riluzole (an important drug for ALS treatment) and (very potently) by polyunsaturated fatty acids (including w3 fatty acids). Another important class of K_2P channels works as sensor of small external pH variations, it has an important role in neuronal apoptosis. Pain is often difficult to treat clinically, particularly neuropathic pain. A variety of "new" channels have been identified recently that are the sensors of painful stimuli in nociceptors. One of these channel families, the ASIC channels, will be described in some details. These Na⁺ (and eventually Ca⁺⁺) permeable channels are activated by acid and are important players in pain perception. One will explain how they work, how they are up regulated by inflammatory stimuli and describe the available high-affinity pharmacology that has been developed.