Design for a slender shaft glass micropipette

A method for the construction of long, slender shaft glass micropipettes is described. The diameter of the pipettes is comparable to metal microelectrodes that are used when multiple penetrations are required to record from neurons in relatively small targets located deep within brain tissue. The advantages of the slender micropipettes over metal microelectrodes are that: (1) the pipettes can be rapidly and reliably produced for consistent shape, size and impedance characteristics, (2) dyes can be used to define recording sites, (3) substances that carry a stable ionic charge such as soluble dyes or drugs can be ionophoreticaly applied through the pipette and, (4) both extra- and intracellular recordings are feasible.