AN EXPERIMENT PROPOSED BY THE IROQUOIS SCHOOL DISTRICT: USING THE STATOCYST SYSTEM TO INVESTIGATE HOW THE VESTIBULAR SYSTEM WOULD PROVIDE ORIENTATION AND BALANCE TO LIVING ORGANISMS IN MICROGRAVITY Objective: Determine if microgravity causes a disturbance in the Vestibular system by using the statocyst system found in sea stars (Echinoderms) as a model system Patch designed by Julianna Ferko 7 th Grade Student Patch designed by Molly Ferko-Comer 9 th Grade Student TEACHER FACILITATOR JENNIFER FOUTZ, IROQUOIS SCHOOL DISTRICT CO-PRINCIPAL INVESTIGATORS MORGAN SCHNARS- GRADE 9 AALIHYA BOWERSOX- GRADE 8 CO-INVESTIGATORS MACKENZIE MOORE- GRADE 8 TAMARA BURTON- GRADE 7 COLLABORATORS BRANDON BRIEGER- GRADE 6 JADON SPRING- GRADE 6

VESTIBULAR SYSTEM STATOCYST SYSTEM Otolith Organs Inner Ear The Statocyst system is located at the junction of sea stars’ legs

HYPOTHE SIS Null Hypothesis (H o ): Microgravity has no effect on the statolith inside the statocyst (no change); sea star behavioral response – it does not try to orient itself Statocyst system operates the same as it would on earth Statolith floats inside statocyst, not coming in contact with any cilia Removal of the statolith resulted in no response in lobsters (Cohen, 1955) Alternative Hypothesis (H A ): Microgravity has an effect on the statolith inside the statocyst; sea star behavioral response – constantly tries to orient itself Statolith is constantly moving, coming in contact with cilia at various locations in the statocyst *These two sea stars are part of the ground truth experiment Asterina Sea Stars

USE OF THE STATOCYST AS A MODEL SYSTEM Both Systems: Geotropic Information provided to the organism’s nervous system Results in a behavioral response SEA STAR Statocyst System HUMANS Otolith Organs

FME MINI- LAB Sea stars chosen had at least three already missing arms Experimental Treatment (Space): Upon its return to Earth, we will measure the growth of each arm and take an average for each Sea Star Control Treatment (Earth): The same experiment will be setup on Earth with one set of Sea Stars undisturbed and one set constantly being rotated at a speed of two rotations per minute We will measure the growth of each arm and take and average for each Sea Star DATA COLLECTION 2.8 mL Salt Water 1 Sea Star 2.8 mL Salt Water 1 Sea Star 2.8 mL Salt Water Clamps are released upon arrival at the ISS to replenish the water.

POTENTIAL RESULTS Sea Star 1: Statocyst operates as it would on earth; optimal environment Sea Star 2: Statolith floats inside statocyst not coming in contact with any cilia; optimal environment Sea Star 3: Statolith comes in continual contact with various points inside statocyst; stressful environment If the microgravity environment provides conflicting information to the brain, the Visual System will take over; therefore it may be important to provide proper visual cues (“up” and “down”) when designing the interior of the spacecrafts and the space station to allow astronauts a sense of orientation SIGNIFICANCE OF RESEARCH Optimal Growth SEASTAR 1 SEASTAR 2 SEASTAR 3

REFEREN CES "Clinical Neurophysiology of the Vestibular System." Google Books. N.p., n.d. Web. 19 Sept < U-zmx9MJ&sig=2lxiBiFr8KWnXjNUTjmsowo4nh Editors of Encyclopædia Britannica. "Port Phillip Bay (bay, Australia)." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 19 Sept "Journey into the world of hearing." Cochlear fluids. N.p., n.d. Web. 19 Sept fluids. fluids "PORT PHILLIP BAY." Port Phillip Bay Taxonomy Toolkit. N.p., n.d. Web. 19 Sept < "Pycnopodia helianthoides." Animal Diversity Web. N.p., n.d. Web. 17 Sept < "statocyst." Merriam-Webster. Merriam-Webster, n.d. Web. 19 Sept "The Smallest Starfish in the World." Animals. N.p., n.d. Web. 19 Sept Web. 10 Nov "Vestibular System: Structure and Function (Section 2, Chapter 10) Neuroscience Online: An Electronic Textbook for the Neurosciences | Department of Neurobiology and Anatomy - The University of Texas Medical School at Houston." Vestibular System: Structure and Function (Section 2, Chapter 10) Neuroscience Online: An Electronic Textbook for the Neurosciences | Department of Neurobiology and Anatomy - The University of Texas Medical School at Houston. N.p., n.d. Web. 19 Sept <

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