Q-Trode Package
Connector assembly for Q-Trode tetrode silicon arrays, optimized for single-unit isolation in hippocampus and other structures.
Overview
The Q-Trode Package (pkg_qtr) provides the assembly for NeuroNexus Q-Trode Series silicon tetrode arrays. A tetrode is a group of four closely spaced recording sites that captures spike waveforms from multiple perspectives simultaneously — the geometric arrangement enables high-accuracy single-unit isolation (spike sorting) even in densely packed structures like hippocampal CA1.
What Is a Tetrode?
A tetrode consists of 4 recording sites arranged in a tight cluster (~25–50µm spacing). When a neuron fires near the tetrode, its spike is detected by all four sites with different amplitudes. This multi-dimensional waveform signature allows spike sorting algorithms to separate neurons that would appear identical on a single electrode.
Q-Trode vs. Traditional Wire Tetrodes
| Property | Wire Tetrodes | Q-Trode Silicon Tetrodes |
|---|---|---|
| Reproducibility | Variable (hand-twisted) | Consistent photolithography |
| Site geometry | Approximate | Precise (±1µm) |
| Durability | Fragile | Silicon substrate |
| Channel count | 4 per drive | Up to 16 tetrodes (64 ch) |
Package Configurations
- CQ4: 4-tetrode bundle (16 channels), Omnetics 18-pin
- HQ4: 4-tetrode high-channel, compatible with Hybrid assembly
- Q4: Standard 4-tetrode package
Applications
- Hippocampal Place Cells: CA1 pyramidal and interneuron isolation during navigation
- Sharp-Wave Ripples: High-frequency oscillation detection with single-unit tagging
- Freely Moving Recording: Lightweight package suitable for mouse and rat
- Grid Cells / Head Direction: Entorhinal cortex and subcortical structure recordings
Related
See also: Q-Trode Series, Spike Sorting