(BSC) The Brain/Tissue Slice Chamber System

This versatile Brain/Tissue Slice Chamber System offers the investigator two in vitro methods of studying perfused thin tissue slices.

The Brain/Tissue Slice Chamber System contains the flowing components:

• The BSC-BUW or BSC-BU Base Units act as a support and warming stand for either the Haas or Zbicz tops listed below.
• The BSC-HT (Haas Top) chamber is an interface-type chamber in which one slice face is maintained wet by a perfusing solution while the other face is maintained moist by a humidified gas mixture.
• The BSC-ZT (Zbicz Top) is a submersion-type chamber in which solutions flow transverse to the fully submerged slices.
• Each top allows for rapid changeover of fluids and both provide excellent access to the slices for electrophysiological recording or other observations.

Slices can be stored ready-to-go with the BSC-PC pre-chamber which allows up to 12 brain slices to be safely stored in vitro while maintaining slice viability. (Available separately.)

Two Models Available

Two base-unit models are available, the BSC-BUW and the BSC-BU. The BSC-BUW is a new, Warner designed version of the legacy BSC-BU base unit. The BSC-BUW is compatible with the Warner TC-324C Temperature controller, while the BSC-BU is compatible with the Med Systems TC-202A temperature controller.

Both temperature controllers are low noise and provide well-filtered DC heating current. This allows even sensitive electrophysiologic recordings, such as single channel patch clamping, to be made without electrical interference.

Convenient

Temperature regulated perfusion lines are built in to the base unot for rapid changeover of superfusing fluids without the need for an external, temperature regulated, perfusate supply tank.

Designed by Experts

Over twenty years ago two leading electrophysiologists, Drs. Haas and Zbicz, designed these chambers for use in their own research. Design improvements employed over the ensuing decades have been enjoyed by electrophysiologists worldwide.

The function of the Base Unit is to warm the superfusing solution in systems using either the Zbicz or Haas tops to study brain/tissue slices.

• Maintains brain slices for 10 hours or more on the bench-top
• Modular design accommodates submersible or interface chambers
• 20 years of use in leading labs
• Sensitive recordings without electrical interference
• Models available for Warner or Med Systems temperature controllers

The Base Units (BSC-BUW or BSC-BU) consist of a double walled cylinder which is usually filled with distilled water and encloses a nichrome heating element. The cavity also contains two separate sets of PVC tubing which can transport one or two superfusing solutions to the slice chamber. The base unit also holds an aerator used to humidify the Haas Top .

The base unit is mounted on legs which suspend the heating cylinder. This prevents artifiacts due to thermal expansion of the heating cylinder from moving the top unit and slice during temperature changes. The base unit is specifically designed to accept both the BSC-HT and the BSC-ZT top units; this makes for economy and versatility.

The Haas Top is an interface-type chamber utilizing semi-submersion principles for the study of brain/tissue slices.

• Maintains a stable intracellular membrane potential of more than 60 mV
• Facilitates action potentials with overshoots close to 100 mV in amplitude, duration of less than 2 msec at 32°C, when used with hippocampal pyramidal and granular cells
• Maintenance of the above potentials is possible for more than 1 hour undisturbed by changes in perfusion fluids
• Preparation slices remain viable for up to 12 hours
• Using flow rates of 1 ml/min, will completely exchange the chamber fluid in less than 1 minute

The Haas Top (BSC-HT) provides for rapid exchange of superfusing fluids, and excellent stability for intracellular recording. Normally used in conjunction with the BSC-BUW or BSC-BU base units and a temperature controller. Slices rest on nylon mesh below which a thin sheet of the perfusate of interest flows. The bottom side of the slice is wet as capillary action saturates the mesh. Slices are oxygenated by a warmed and humidified mixture of 95/5% O₂/CO₂ which flows across the top surface of the slice. The BSC-HT has been designed so that the effects of two drugs can be studied simultaneously. One drug flows down the left portion of the chamber and the second down the right.

The Zbicz Top is a submersion-type chamber in which tissue slices are supported on a stiff nylon mesh. Slices are perfused both from below and above.

• Slices remain viable for 10 hours or more
• Slices are mechanically stable
• Low volume chamber cavity
• Slices are wetted on both top and bottom and do not dry out
• Semipermanent mesh slice support is easily cleaned
• Low electrode capacitance assists single microelectrode voltage and patch clamping
• Minimal bubble formation
• Precise solution temperature regulation
• Slice can be trans-illuminated

Slices remain viable for 10 hours or more

The Zbicz Top (BSC-ZT) is a submersion-type chamber in which tissue slices are supported on a nylon mesh. The perfusate flows transversely across both cut surfaces. The steady flow of warmed media across the slightly submerged slice surfaces is sufficient to keep many tissues alive and responsive for 10 or more hours.

The fluid level is set to 1 mm above the mesh by a dam at the end of the chamber. The chamber is 6 mm wide and the trough is 24 mm long; this provides adequate room for slices and instrumentation, yet minimizes the well volume to optimize drug change over times. Fluid overflowing the dam is drained via a vacuum line to waste.

Slices are mechanically stable

Slices are placed on a special ribbed nylon mesh and may be held in place by 3 to 4 stimulating electrodes or a plastic insert. This stability is attributed to the stiff nylon mesh which does not rise or sag with changes in fluid flow, therefore moderate changes in the transverse laminar flow can be well tolerated during intracellular and extracellular recordings. These features allow for switching of solutions with minimal risk of tissue movement and loss of neurons while recording.

Low volume chamber

The low volume of the chamber cavity and the relatively fast flow rate allows rapid exchange of solution (1 to 2 minutes) which facilitates drug application studies.

Slices remain moist

Slices remain moist and viable, because they are wetted on both sides and do not dry out due to surrounding air currents.

Semipermanent mesh

The mesh surface holding the slice is semipermanent and can be cleaned easily. The BSC-ZT comes with extra mesh which can be installed easily when necessary.

Low electrode capacitance

Because the fluid depth is shallow (400 to 600 microns), the electrode capacitance remains low; an important consideration in single microelectrode voltage and patch clamping.

Minimal bubble formation

Bubbles, which can form in the heating unit, escape by the path formed at the entrance of the trough. Movement of the slice will not result if bubbles inadvertently form under the mesh. The flow of solution over the slice top will maintain tissue viability.

The Pre-chamber allows multiple brain slices to be stored in vitro for hours while maintaining excellent viability prior to study using either the BSC-HT or BSC-ZT.

• 10 to 12 brain slices can be stored in vitro
• 95% O2 /5% CO2 mixture bubbled through normal saline
• Cyclic flow of oxygen enriched perfusate
• Continuous permeation of stored slices
• Slices remain viable for hours
• Includes insert

The Pre-chamber (BSC-PC) chamber allows up to 12 brain slices to be safely stored in vitrowhile maintaining excellent slice viability.

A mixture of 95% O₂ /5% CO₂ is bubbled through physiological saline within the chamber. This initiates a circular flow of oxygen enriched saline which continuously permeates the slices. Slices can remain viable for hours while awaiting transfer to an examining chamber. Gas flow pressure should not exceed 5 p.s.i.

Insert is included.