Recording Neural Activity in Freely Moving Mice Using Fiber Photometry

Abstract

Source: Martianova, E., et al. Multi-Fiber Photometry to Record Neural Activity in Freely-Moving Animals. J. Vis. Exp. (2019).

This video demonstrates a method for recording neural activity in a freely moving mouse using fiber photometry. In this method, neurons in a specific brain region express a genetically encoded calcium indicator. A stimulus is applied to this brain region, and the stimulus-dependent change in fluorescence is measured to identify neural activity.

Protocol

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.

1. Alignment of the optical path between the CMOS (complementary metal oxide semiconductor) camera and the individual or branching patch cord

1. Loosen all screws on the 5-axis translator (Figure 1B).
2. Screw in the patch cord (Figure 1B) to the adaptor [SMA (sub-miniature A) or FC (fiber optic connector)] that is affixed to the 5-axis translator.
3. Turn on the 470 nm excitation light (Figure 1B) at low pow....

Results

Figure 1: Fiber photometry schematic. (A) The excitation light from two LEDs (410 nm and 470 nm) passes through a series of filters and dichroic mirrors and produces an excitation spot at the working distance of the 20x objective. The light passes.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
1/4"-20 Stainless Steel Cap Screw, 1" Long	Thorlabs	SH25S100
1/4"-20 Stainless Steel Cap Screw, 1/2" Long	Thorlabs	SH25S050
1/4"-20 Stainless Steel Cap Screw, 3/8" Long	Thorlabs	SH25S038
1000 µm, 0.50 NA, SMA-SMA Fiber Patch Cable	Thorlabs	M59L01
12.7 mm Optical Post	Thorlabs	TR30/M
12.7 mm Pedestal Post Holder	Thorlabs	PH20EM
15 V, 2.4 A Power Supply Unit with 3.5 mm Jack Connector for T-Cube	Thorlabs	KPS101
20x objective	Thorlabs	RMS20X
30 mm Cage Cube with Dichroic Filter Mount	Thorlabs	CM1-DCH/M
405 nm LED	Doric Lenses	CLED_405
410 nm bandpass filter	Thorlabs	FB410-10
465 nm. LED	Doric Lenses	CLED_465
470 nm bandpass filter	Thorlabs	FB470-10
560 nm bandpass filter	Semrock	FF01-560/14-25
560 nm LED	Doric Lenses	CLED_560
5-axis kinematic Mount	Thorlabs	K5X1
Achromatic Doublet	Thorlabs	AC254-035-A-ML
Adaptor for 405 collimator	Thorlabs	AD11F
Adaptor for ajustable collimator	Thorlabs	AD127-F
Aluminum Breadboard	Thorlabs	MB1824
Clamping Fork	Thorlabs	CF125
Cube connector	Thorlabs	CM1-CC
Dual 493/574 dichroic	Semrock	FF493/574-Di01-25x36
Emission filter for GCaMP6	Semrock	FF01-535/22-25
Enclosure with Black Hardboard Panels	Thorlabs	XE25C9
Externally SM1-Threaded End Cap for Machining	Thorlabs	SM1CP2M
Fast-change SM1 Lens Tube Filter Holder	Thorlabs	SM1QP
Fixed Collimator for 405 nm light	Thorlabs	F671SMA-405
Fixed collimator for 470 and 560 nm light	Thorlabs	F240SMA-532
Green emission filter	Semrock	FF01-520/35-25	In light beam splitter
High-Resolution USB 3.0 CMOS Camera	Thorlabs	DCC3260M
Light beam splitter	Neurophotometrics	SPLIT
Longpass Dichroic Mirror, 425 nm Cutoff	Thorlabs	DMLP425R
Longpass Dichroic Mirror, 495 nm Cutoff	Semrock	FF495-Di03
Metabond dental cement	C&B
M8 - M8 cable	Doric Lenses	Cable_M8-M8
Optic fiber cannulas	Doric Lenses		Need to specify that these will be used to photometry experiments requiring low autofluorescence
Optic fiber Patchcords	Doric Lenses		Need to specify that these will be used to photometry experiments requiring low autofluorescence
Red emission filter	Semrock	FF01-600/37-25	In light beam splitter
T7 LabJack	LabJack
T-cube LED Driver	Thorlabs	LEDD1B
USB 3.0 I/O Cable, Hirose 25, for DCC3240	Thorlabs	CAB-DCU-T3