This paper describes a simple-to-build minipump-chemitrode assembly which can be used for long term electrophysiological, chemical and behavioural studies. This system consists of an osmotic minipump, a cannula and an array of nine electrodes which are connected to a miniature Winchester Socket. A detailed plan for construction of both the chemitrode and the minipump-chemitrode is given together with some suggestions for possible usages in brain research(such as kindling). The osmotic minipump consists of a collapsible reservoir of flexible, impermeable material, surrounded by a sealed layer containing an osmotic agent--all of which is contained by a semipermeable membrane. Imbibed water generates hydrostatic pressure on the flexible lining of the reservoir, gradually compressing it, producing a constant flow of its contents through the delivery portal.