Microtubules are cylindrically shaped cytoskeletal biopolymers that are essential for cell motility, cell-division and intracellular trafficking by motor proteins kinesin and dynein. In neuronal cells they play the important roles in higher cognitive functions including learning, memory and consciousness. Experimental evidence suggests that microtubules act as biological electrical wires that can transmit and amplify electric signals via the flow of condensed ionic clouds. We here present some of our contributions aimed to elucidate the versatile biological functions in microtubules.