bbio 495-symposium presentation.pptx
TRANSCRIPT
The Effects of Ultrasound on Planarian Photoreceptor RegenerationANDREW TAGLE | ROSE-ANNE NICOLAS | JASMINE REYES | BEZA NEGUSSIE
Why this topic?◦Personal interests:
◦Diagnostic imaging
◦Ultrasound and skincare (Hissong, et. al)
◦ Application of ultrasound has shown:
◦ Accelerated muscle healing in rats (Montali et. al)
◦ Enhanced blood flow, increased membrane permeability, altered connective tissue permeability and nerve conduction in living tissue (Binder et. al)
◦ Faster bone regeneration in rabbits (Takebe et. al)
◦ Treatment of Alzheimer's in rats (Hynynen et. al)
Planaria
◦ Capable of regenerating lost body parts
◦ Pieces up to 1/279th of the organism can still regenerate a head
◦ Contain tissues and organs homologous to humans
◦ Model organism for investigating regeneration
Background
Morphological and Functional Recovery of the Planarian Photosensing System during Head Regeneration-Takeshi Inoue, et. Al
◦ Planaria exhibit negative phototaxis (light avoidance behavior)
◦ Intact planaria able to detect direction of light
◦ Decapitated planaria unable to recognize direction of light
Planaria Exhibit Negative Phototaxis by Day 5
Morphological and Functional Recovery of the Planarian Photosensing System during Head Regeneration-Takeshi Inoue, et. Al
Previous Ultrasound Experiment◦ Applied ultrasound different days after cut◦ Concluded that applying ultrasound one day after decapitation was most beneficial
Ultrasound’s effects on planarian photoreceptor regeneration-Chan et., al
◦ Challenges: Budding
How can we stop budding?
◦Planaria will bud (fission) and split apart from each other
◦ Ran experiments to reduce budding
◦ Cut in two different areas
◦ Placed planaria in 100 mL of water or 200 mL of water
Voltage Test
◦Find voltage to use for ultrasound application
◦3 Groups that receive 60 seconds of ultrasound◦200 mV (n=10)◦300 mV (n=10)◦400 mV (n=10)
◦ Timed how long it takes for each planaria to escape inner ring
Ultrasound Application
◦ Planaria cut near tail to reduce budding 24 hours . . .◦ Planaria were treated with 200 mV of
ultrasound ~24 hours after being cut
◦ 3 groups (n=36)
◦ Control: No treatment (n=12)
◦ 1 treatment (n=12)
◦ 2 treatments (n=12)
◦ Proceed with phototaxis assay
How to Test Photoreceptor Function
◦ Planaria exhibit negative phototaxis ◦ Shadow box
◦ Acclimate planaria to dark ~15 minutes prior to testing
◦ Conducted in a dark room
◦ Test for 90 seconds
◦ Conduct assay on Day 0 and Day 3-Day 7 and on day 9
◦ Hoped to see difference between treated planaria and control.
Control Results
Shadow Box Results
*** ******
**
NS
***
= p < 0.001
= p < 0.01
NS = Non Significant
*****
Control vs. 1 US Treatment Results
Shadow Box Results
NS
NS
*** ***** *** ****** *** ***
*
**
**
***
= p < 0.001
= p < 0.01
NS = Non Significant
**
Control vs. 2 US Treatment Results
Shadow Box Results
NS NSNS
*** ****** ***
***
*** ***
****
***
= p < 0.001
= p < 0.01
NS = Non Significant
**
Summary ◦Using tail piece of planaria help reduce budding
◦Applying 2 doses of 200 mV of ultrasound at 30 minutes aparts improves photoreceptor regeneration
◦Takes ~7-9 days for tail piece to reach day 0 performance in phototaxis assay
Acknowledgements
◦ Bryan White
◦ Pierre Mourad
◦ Cameron Whalen
◦ Ivan Owen
◦ Engineering program for sharing their lab with us