According to one or more embodiments of the present invention, a crossbar array includes a cross-point synaptic device at each cross-point. The cross-point synaptic device includes a transistor that includes a first ion reservoir formed on a source and on a drain of the transistor. The transistor further includes an ion conductivity electrolyte layer formed on the first ion reservoir. The transistor further includes a second ion reservoir formed on the ion conductivity electrolyte layer. The transistor further includes a gate formed on the second ion reservoir.