Supplementary Information
Striatal dopamine D1 receptor is essential for contextual fear conditioning
Masaru Ikegami1, Takeshi Uemura1,2, Ayumi Kishioka1, Kenji Sakimura3 and Masayoshi
Mishina1,4,*
1
Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine,
University of Tokyo, Tokyo, Japan
2
Department of Molecular and Cellular Physiology, Shinshu University School of Medicine,
Nagano, Japan
3
Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata,
Japan
4
Brain Science Laboratory, The Research Organization of Science and Technology,
Ritsumeikan University, Kusatsu, Shiga, Japan
*Correspondence to mmishina@fc.ritsumei.ac.jp
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Supplementary Figure
Supplementary Figure S1. Sensitivities of striatum-specific D1R and D2R KO mice to
footshocks. (A and B) The minimal amounts of currents required to elicit flinch, vocalization
and jump in responses to footshock were determined for control and striatum-specific D1R KO
mice (n = 8 each) in (A) and for control and striatum-specific D2R KO mice (n = 8 each) in (B).
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Supplementary Figure S2. Locomotor activities of D1R and D2R KO mice in the
conditioning chamber during the 3-min preshock period. (A and B) Locomotor activities
were recorded during the 3-min preshock period on the conditioning day. (A) The total
distance travelled by control and striatum-specific D1R KO mice (n = 13 each). (B) The total
distance travelled by control (n = 9) and striatum-specific D2R KO mice (n = 12).
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Supplementary Figure S3. The amounts of D1R and D2R proteins in cerebral cortex,
hippocampus and striatum. (A) Full-length western blots of Fig. 5C. (B) Full-length western
blots of Fig. 5D. The same membranes were used for D2R blotting and actin blotting.
Supplementary Methods
Pain sensitivity. Pain sensitivity was examined according to the previous procedure as
described previously19. The measure of pain sensitivity was carried out in a clear chamber (10
× 10 × 10 cm) with a floor consisting of 14 stainless steel rods, 2 mm diameter, spaced 7 mm
apart. Each mouse was placed individually in the testing chamber and received a series of
ascending footshocks to determine current thresholds at which each mouse would exhibit
flinch, jump and vocalization responses. Each mouse received 1 s shocks in 0.05 mA
increments from 0.05 to 0.5 mA, 30 s apart. When these behaviours are observed the sequence
is terminated.
Locomotor activity. Behaviours of mice during fear conditioning were monitored by a CCD
camera attached to the ceiling of the chest. Images were captured at a rate of two frames per
second, and the total distance traveled during the 3-min preshock period in the conditioning
chamber was measured using ImageJ software (National Institutes of Health, Maryland, USA).
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