A CLOSED FLOW CHAMBER FOR LONG-TERM MULTICHANNEL RECORDING AND OPTICAL MONITORING

An autoclavable chamber and associated medium circulation system has b een constructed to provide a stable environment for mammalian cultures for long periods of time. The chamber was specifically designed for ( a) multichannel electrophysiological recording from monolayer networks with photoetched multielectrode matrices, (b) for microscope observat ions of networks in the living state and (c) for the manipulation of s uch networks with laser cell surgery. The chamber components can be as sembled under sterile conditions in less than 30 s to minimize pH and osmolarity stress to the monolayer cultures. An open chamber version p rovides a constant medium bath for pharmacological studies. The closed chamber version, attached to a 10-ml medium reservoir and a peristalt ic pump, has so far provided constant conditions for continual recordi ng over an 8-day period. Flow characteristics within the closed chambe r, optical properties, pH maintenance, and schemes for drug addition a re described.