A method is provided that includes positioning electrodes in or in contact with a head of a subject identified as in need of enhanced microglial cell activation. Control circuitry is activated to drive the electrodes to apply an electrical current to a brain of the subject in pulses having an average pulse duration of between 0.1 ms and 10 ms, and to configure the electrical current to enhance microglial cell activation for taking up amyloid beta or tau protein from brain parenchyma. The control circuitry is activated to apply the electrical current with an average amplitude of between 0.1 and 5 mA, or with an average voltage that results in between 0.1 and 5 mA current. Other embodiments are also described.
