Device and method for concomitant ejection and suction of perfusate

An assembly for identifying a region of interest and for concomitant ejection and suction of a perfusate within a region of interest without spillover of said perfusate to a juxtaposed anatomical region, comprising:

• a recording chamber containing artificial cerebrospinal fluid, such that a tissue slice can be submerged in the fluid and disposed within the recording chamber, the tissue slice having a region of interest and a juxtaposed anatomic region;
• an electrode disposed within the recording chamber, the electrode adapted to be disposed on the tissue slice to identify a region of interest as indicated by responses from neurons within the tissue slice;
• and
• a concomitant ejection and suction device in communication with the recording chamber and adapted to interact with the region of interest identified by the electrode, the concomitant ejection and suction device including
• an inflow manifold having a proximal end and a distal end, said proximal end of said inflow manifold being coupled to a cistern containing said perfusate to be delivered to said region of interest;
• an inflow control mechanism coupled to said inflow manifold, wherein said inflow control mechanism includes a stopper or regulator;
• an outflow manifold having a proximal end and a distal end, said proximal end of said outflow manifold being coupled to a reservoir and an outflow control mechanism to control a rate of suction of said perfusate out of said region of interest and into said reservoir, wherein said outflow control mechanism includes a variable speed peristaltic pump and a stopper or regulator;
• an inflow tip disposed at said distal end of said inflow manifold;
• an outflow tip disposed at said distal end of said outflow manifold,
• wherein said outflow tip has an inner diameter larger than an inner diameter of said inflow tip to ensure that said outflow manifold suctions said perfusate out of said region of interest,
• said inflow tip and said outflow tip externally juxtaposed from and in a staggered relationship with each other and collectively forming a microfluidic application tip of said device, such that said microfluidic application tip both discharges and suctions said perfusate into and out of said region of interest nearly simultaneously while allowing said perfusate to have a measurable effect within said region of interest, wherein as said inflow manifold discharges said perfusate into said region of interest, said outflow manifold nearly simultaneously suctions said perfusate out of said region of interest so that said perfusate cannot spillover into said juxtaposed anatomical region from said region of interest;
• and
• a micromanipulator to position said microfluidic application tip precisely within said region of interest;
• wherein said inflow manifold and said outflow manifold are indirectly coupled to each other via a rigid support member to permit precise positioning of said microfluidic tip, said rigid support member being an elongate rod disposed between said inflow manifold and said outflow manifold,
• wherein a flow rate of said perfusate through said outflow manifold is higher than a flow rate of said perfusate through said inflow manifold.