Experiment/chapman 2026 mouse piriform
From Miniscope
Mouse anterior piriform cortex imaging during freely moving odour sampling
Chronic aPC imaging across five consecutive days of passive odour presentation, tracking the same neurons to test how stable odour representations are.
Extracted from full textTranscribed by a curator from the published methods section. Values not stated in the paper are marked as not reported rather than inferred.
Animal
Species
Mouse
Strain
C57BL/6 (JAX 000664)
Age at surgery
Surgeries began at approximately 12 weeks
Animals
14
Target
Brain region
Coordinates
AP +1.7, ML +2.3 from bregma; injector lowered 3.3 mm from the brain surface
Hemisphere
Right
Cell type
Piriform layer 2 and 3 neurons
Indicator
Indicator
GCaMP6s
Reports
Calcium
Delivery
AAV injection
Construct
AAV1-hSyn-GCaMP6s-WPRE-SV40 (Addgene 100843-AAV1)
Injection volume
500 nL at 5 nL/s
Expression time
2 weeks between injection and lens implantation
Optical access
Method
GRIN lens
Lens
0.5 x 6.1 mm (Inscopix), seated through a 0.6 mm craniotomy
Implant depth
Lowered in 1 mm steps with a 5 min rest at each step
Surgery staging
Separate surgeries
Injection to implant
2 weeks
Imaging
Scope
Condition
Freely behaving
Sessions
Five consecutive daily sessions; six odorants x ten trials per session
Behavior
Passive odour presentation, Free odour sampling
Analysis
CaImAn, CellReg, DeepLabCut
Cell yield
686 neurons from 14 mice tracked across all five sessions
What was hard about this preparation
The authors note substantial background activity from the freely moving state, and that odour representations drifted across sessions in a way that correlated with how much the animal investigated -- so cell tracking alone does not guarantee stable tuning.
Who to ask
Experimenter
Ian F. Chapman, Max L. Fletcher
Institution
University of Tennessee Health Science Center; Monell Chemical Senses Center
Resources
Notes
Frame rate, gain and LED power were tuned per mouse and then held constant across days, so no single frame rate is reported. A passive commutator (ONE Core, University of Colorado) kept the animal untethered in yaw. A parietal skull screw anchored the headcap.