PMID- 32457580
OWN - NLM
STAT- MEDLINE
DCOM- 20210610
LR  - 20240329
IS  - 1662-5110 (Electronic)
IS  - 1662-5110 (Linking)
VI  - 14
DP  - 2020
TI  - The Photoconvertible Fluorescent Probe, CaMPARI, Labels Active Neurons in 
      Freely-Moving Intact Adult Fruit Flies.
PG  - 22
LID - 10.3389/fncir.2020.00022 [doi]
LID - 22
AB  - Linking neural circuitry to behavior by mapping active neurons in vivo is a 
      challenge. Both genetically encoded calcium indicators (GECIs) and intermediate 
      early genes (IEGs) have been used to pinpoint active neurons during a stimulus or 
      behavior but have drawbacks such as limiting the movement of the organism, 
      requiring a priori knowledge of the active region or having poor temporal 
      resolution. Calcium-modulated photoactivatable ratiometric integrator (CaMPARI) 
      was engineered to overcome these spatial-temporal challenges. CaMPARI is a 
      photoconvertible protein that only converts from green to red fluorescence in the 
      presence of high calcium concentration and 405 nm light. This allows the 
      experimenter to precisely mark active neurons within defined temporal windows. 
      The photoconversion can then be quantified by taking the ratio of the red 
      fluorescence to the green. CaMPARI promises the ability to trace active neurons 
      during a specific stimulus; however, CaMPARI's uses in adult Drosophila have been 
      limited to photoconversion during fly immobilization. Here, we demonstrate a 
      method that allows photoconversion of multiple freely-moving intact adult flies 
      during a stimulus. Flies were placed in a dish with filter paper wet with acetic 
      acid (pH = 2) or neutralized acetic acid (pH = 7) and exposed to photoconvertible 
      light (60 mW) for 30 min (500 ms on, 200 ms off). Immediately following 
      photoconversion, whole flies were fixed and imaged by confocal microscopy. The 
      red:green ratio was quantified for the DC4 glomerulus, a bundle of neurons 
      expressing Ir64a, an ionotropic receptor that senses acids in the Drosophila 
      antennal lobe. Flies exposed to acetic acid showed 1.3-fold greater 
      photoconversion than flies exposed to neutralized acetic acid. This finding was 
      recapitulated using a more physiological stimulus of apple cider vinegar. These 
      results indicate that CaMPARI can be used to label neurons in intact, 
      freely-moving adult flies and will be useful for identifying the circuitry 
      underlying complex behaviors.
CI  - Copyright (c) 2020 Edwards, Hoppa and Bosco.
FAU - Edwards, Katie A
AU  - Edwards KA
AD  - Department of Molecular and Systems Biology, Geisel School of Medicine, Dartmouth 
      College, Hanover, NH, United States.
FAU - Hoppa, Michael B
AU  - Hoppa MB
AD  - Department of Biological Sciences, Dartmouth College, Hanover, NH, United States.
FAU - Bosco, Giovanni
AU  - Bosco G
AD  - Department of Molecular and Systems Biology, Geisel School of Medicine, Dartmouth 
      College, Hanover, NH, United States.
LA  - eng
GR  - DP1 MH110234/MH/NIMH NIH HHS/United States
GR  - P20 GM113132/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20200508
PL  - Switzerland
TA  - Front Neural Circuits
JT  - Frontiers in neural circuits
JID - 101477940
RN  - 0 (Fluorescent Dyes)
RN  - 0 (Photoaffinity Labels)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Age Factors
MH  - Animals
MH  - Animals, Genetically Modified
MH  - Calcium/analysis/*metabolism
MH  - Drosophila melanogaster
MH  - Fluorescent Dyes/analysis/*metabolism
MH  - Locomotion/*physiology
MH  - Neurons/chemistry/*metabolism
MH  - Photoaffinity Labels/analysis/metabolism
MH  - Staining and Labeling/methods
PMC - PMC7227398
OTO - NOTNLM
OT  - CaMPARI
OT  - Drosophila melanogaster
OT  - behavior
OT  - optogenetics
OT  - photoconversion
EDAT- 2020/05/28 06:00
MHDA- 2021/06/11 06:00
PMCR- 2020/01/01
CRDT- 2020/05/28 06:00
PHST- 2020/02/18 00:00 [received]
PHST- 2020/04/14 00:00 [accepted]
PHST- 2020/05/28 06:00 [entrez]
PHST- 2020/05/28 06:00 [pubmed]
PHST- 2021/06/11 06:00 [medline]
PHST- 2020/01/01 00:00 [pmc-release]
AID - 10.3389/fncir.2020.00022 [doi]
PST - epublish
SO  - Front Neural Circuits. 2020 May 8;14:22. doi: 10.3389/fncir.2020.00022. 
      eCollection 2020.