5 min read
Updated September 9, 2025
The rDBSA (research Deep Brain Stimulation Array) carries clinical DBS electrode geometry into research use. It combines microstimulation and recording on one array, acute or chronic, and reaches targets a standard laminar probe cannot.
Research use only. NeuroNexus products and the procedures described here are for non-clinical research use, and must not be used in human or veterinary medical procedures.
What the rDBSA is#
Clinical DBS leads are built for therapy, so their contacts are large and few. A research array asks a different question: where, exactly, does the effect come from. The rDBSA answers it by placing more and smaller contacts along the same trajectory a clinical lead would take.
The result is a linear contact array on a long, slim shank, addressable channel by channel. Contacts can stimulate, record, or do both within one session.
Recording and stimulation on one array#
Separating the stimulating contact from the recording contact by a known distance is the experimental point. It lets you ask what the tissue did, at a measured offset from where the current went in.
Two consequences follow for experimental design:
- Stimulation artifact sets your usable window. Plan the recovery interval before the protocol, not after the first session.
- Contact selection is a variable, not a setting. Record the exact contacts used in every trial; the spatial claim depends on it.
Closed-loop protocols use the same property. Recording contacts supply the trigger, stimulating contacts deliver the response, and both live on one implanted array.
Deep targets and long trajectories#
Subthalamic nucleus and globus pallidus work in large-brain models needs shank lengths a cortical probe does not provide. rDBSA designs run to tens of millimetres of penetration depth, on a lead diameter chosen to keep the insertion tract narrow.
Two things follow from the length:
- Trajectory error accumulates with depth. A one-degree angular error is small at 5 mm and material at 45 mm. Plan the approach with imaging, and verify the track histologically.
- Insertion speed matters more, not less. A long shank displaces tissue along its whole path.
Small-animal configurations#
A rat-sized rDBSA exists for rodent DBS models, developed with a collaborating rodent DBS laboratory. It keeps the contact arrangement and scales the geometry to rat anatomy. A protocol developed in rodents then transfers to a larger model without changing the recording approach.
Research applications#
- Movement disorder models — stimulation of STN and GP, with simultaneous recording of the stimulated and downstream structures.
- Psychiatric and pain models — targeted stimulation where the mechanism, not the therapy, is the object of study.
- Epilepsy models — responsive stimulation triggered from recorded activity.
- Mechanism studies — separating direct activation from network-level effect by recording at a known distance from the stimulating contact.
Experimental considerations#
| Consideration | What goes wrong | Settle it |
|---|---|---|
| Stereotactic compatibility | The holder does not grip the lead diameter you ordered, discovered on surgery day | Confirm the manipulator's collet against the ordered lead diameter before the first surgery |
| Chronic fixation | A 45-60 mm lead is a lever; torque at the entry point unseats the anchor | Anchor close to the entry point and support the span between skull and connector |
| Charge density | Small contacts reach charge-density limits at currents a clinical contact tolerates | Establish the safe envelope for your contact geometry before the protocol, not during it |
| Impedance tracking | A mechanical failure is read as a biological change | Measure at implant and every session; a rise on one contact is usually mechanical |
Configurations and ordering#
rDBSA is configured to the target. Eight package configurations are currently orderable, all 32-channel on an Omnetics 32-pin connector, differing in cannula length and in how the assembly is protected:
| Configuration | Channels | Cannula length | Protective covering | Connector |
|---|---|---|---|---|
| rdbsa32_cc_cl32 | 32 | 32 mm | Epoxy | Omnetics 32-pin |
| rdbsa32_a_cl35 | 32 | 35 mm | 3D-printed polymer case | Omnetics 32-pin |
| rdbsa32_c_cl35 | 32 | 35 mm | 3D-printed titanium housing | Omnetics 32-pin |
| rdbsa32_cc_cl35 | 32 | 35 mm | Epoxy | Omnetics 32-pin |
| rdbsa32_a_cl45 | 32 | 45 mm | 3D-printed polymer case | Omnetics 32-pin |
| rdbsa32_c_cl45 | 32 | 45 mm | 3D-printed titanium housing | Omnetics 32-pin |
| rdbsa32_c_cl60 | 32 | 60 mm | 3D-printed titanium housing | Omnetics 32-pin |
| rdbsa32_cc_cl60 | 32 | 60 mm | Epoxy | Omnetics 32-pin |
The 32-60 mm span is what "tens of millimetres" means in practice, and it is set by the target: STN and GP in a large-brain model sit at different depths from the same entry. The lead designs themselves — including the 40-contact and rat-scale variants — are built to order rather than stocked, so the configuration you can have is a conversation with an application scientist, not a catalog lookup. Materials and contact geometry change with the release. Do not rely on a figure quoted in a document.