Recording Span
Hardware
Vertical distance from first to last recording site on a probe.
Recording span (also called shank length or site span) is the total vertical distance covered by recording sites along a probe, measured in micrometers or millimeters. This determines how much tissue depth you can sample simultaneously.
Why it matters: Recording span defines your spatial coverage across tissue layers or brain regions. Larger spans let you record from multiple cortical layers or across different anatomical structures in a single penetration.
Common spans:
- Small (1-3 mm): Single cortical layer, focused recordings
- Medium (3-6 mm): Multi-layer cortical recordings, hippocampal studies
- Large (6-10 mm): Deep brain structures, cross-region connectivity
Selection guidance: Choose span based on your target brain region(s) and whether you need simultaneous recording across multiple layers or areas. Longer spans are more rigid and may cause more tissue damage during insertion.