Biology Department: David Scholnick
Professor of Biology
- B. A., Biology, University of San Diego
- M. A. Biology, College of William and Mary, Virginia
- Ph.D., Animal Physiology, University of Colorado at Boulder
- Postdoctoral Research, University of Colorado at Boulder
- Biology 202: General Biology I
- Biology 470: Animal Physiology
- Biology 145: Marine biology for Non science Majors
- Biology 345: Marine Biology
David Scholnick, associate professor of biology, was recently featured on the Discovery Channel (Daily Planet) with research students Nathan Gilpin (exercise science senior) and Kristen Dick (biology sophomore). Check out the link to see them examining Oregon lizards sick with malaria, collecting them and bringing to campus to better understand the disease and its impacts on animals in North America.
Discovery Channel. Daily Planet.
Today Show Appearance How a shrimp on a treadmill became a Web sensation
Pacific University’s David Scholnick and College of Charleston’s Lou Burnett spoke to Today Show hosts Matt Lauer, Meredith Vieira and Al Roker about their research entitled "Shrimp on Treadmill". The research started as a simple investigation on the impact of bacteria on shrimp and soon turned into an Internet sensation.
Worldwide animals are at an increased risk of opportunistic pathogens. Elevations in temperature and increased areas of low oxygen, suggest that pathogen exposure of lower vertebrates and marine invertebrates are escalating.
The central hypothesis underlying my research is that infectious disease can compromise the respiratory systems of lower vertebrates and invertebrates and thereby limit the ability of animals to sustain and recover from normal activities.
Working with colleagues at College of Charleston's Grice Marine Laboratory and Hollings Marine Laboratory in Charleston, South Carolina, we have demonstrated that in resting animals bacterial infection can compromise normal metabolic function. Following infection, aerobic respiration rates are down regulated and lactate levels increase in resting animals.
At Pacific University my students and I will examine the relationship between host and pathogen in lower vertebrates and invertebrates during activity and recovery. Studies will be conducted using local lizards that are infected with Plasmodium-the hemoparasite that causes malaria in a wide range of vertebrates-to determine if infected lizards have limited respiratory capacity.
Many lizard populations are regularly infected with Plasmodium which is transmitted via blood sucking invertebrates. Previous research has shown that many of the physiological disruption experienced by lizards are similar to those seen in humans. Infected lizards have reduced oxygen uptake, suffer from anemia, and have reduced fat stores.
My students and I will examine the thermoregulatory ability of infected and uninfected lizards at rest and following activity. Additional studies will determine changes in metabolism, recovery, and lactate in lizards exposed to the malarial parasite.
In a separate set of experiments, penaeid shrimp that typically inhabit estuaries and regularly encounter high temperatures and low oxygen levels will be used to examine whether bacterial infection can alter anaerobic pathways. In these studies, shrimp infected with pathogenic bacteria will be exercised on small treadmills and changes in lactate, oxygen consumption, and activity monitored. These experiments will indicate whether sublethal infection can suppress normal respiratory activity and limit recovery.
The goal of these studies is to better understanding how pathogens can impact respiration and thereby disrupt metabolic pathways during activity.
I strongly support undergraduate research at all levels and have found that involving undergraduates in research is one of the most valuable educational experiences in the sciences. In the past I have been involved in undergraduate research projects that have given rise to several publications, presentations at national meetings as well as job and graduate school opportunities .
I feel that the most effective way students can develop independent thought and creativity is through research. I encourage students interested in getting involved in research projects to talk with me about possible opportunities during the academic year and summer.
* Indicates undergraduate research student
Scholnick, D. A., T. Bates*, R. Manivanh*, S. McAlexander* and O. Savenkova*. 2010. Impact of malarial infection on metabolism and thermoregulation in the fence lizard fence lizard, Sceloporus occidentalis. Journal of Herpetology (In Press).
Scholnick, D. A., A. E. Barabas* S. S. Cowan*. 2006. Influence of chloride on glucose export in marine crabs: Activation of glucose-6-phosphatase by chloride ion. J. Crustacean Biol. 26:510-514.
Scholnick, D. A., K. G. Burnett and L. E. Burnett. 2006. Impact of exposure to bacteria on metabolism in the Penaeid shrimp Litopenaeus vannamei. Biological Bulletin 211:44-49.
Petersen*, A. M., T. T. Gleeson, and D. A. Scholnick. 2003. The effect of oxygen and adenosine on the thermoregulation of lizards. Physiol. Biochem. Zool. 76:339-347.
Burnett, L., N. Terwilliger, A. Carroll, D. Jorgensen, D. Scholnick. 2002. Respiratory and acid-base physiology of the purple sea urchin, Strongylocentrotus purpuratus, during air exposure: Presence and function of a facultative lung. Biol. Bull. 203:42-50.
Wallert, M., J. Foster, D. Scholnick, S. Olmschnek, B. Kuehn, and J. Provost. 2001. Kinetic analysis of glucose-6-phosphatase: An investigative approach to carbohydrate metabolism and kinetics. Biochem. Mol. Biol. Ed. 29:199-203.
Nedrow, J. A., D. A. Scholnick, and T. T. Gleeson. 2001. Roles of lactate and catecholamines in the energetics of brief locomotion in an ectothermic vertebrate. J. Comp. Physiol. B. 171:237-245.
Scholnick, D.A. and T. T. Gleeson. 2000. Activity before exercise influences recovery metabolism in the lizard Dipsosaurus dorsalis. J. Exp. Biol. 203:1809-1815.
Wagner, E. L., D. A. Scholnick and T. T. Gleeson. 1999. The roles of acidosis and lactate in the behavioral hypothermia of exhausted lizards. J. Exp. Biol. 202:325-331.
Scholnick, D. A. and T. T. Gleeson. 1997. The influence of corticosterone and glucacon on metabolic recovery from exhaustive exercise in the desert iguana Dipsosaurus dorsalis. Gen. Comp. Endocrinol. 106:147-154.
Horn, D. B., D. A. Podolin, J. E. Friedman, D. A. Scholnick and R. S. Mazzeo, 1997. Alterations in key gluconeogenic regulators with age and endurance training. Metabolism, 46:414-419.
Scholnick, D. A. and G. K. Snyder, 1996. Physiological response of the tadpole shrimp Triops longicaudatus to hypoxia. Crustaceana, 69:937-948.
Scholnick, D. A. and T. T. Gleeson, 1996. Regulation of skeletal muscle metabolism in the lizard Dipsosaurus dorsalis by fructose-2,6-bisphosphate. American Journal of Physiology, 271:R1447-R1451.
Scholnick, D. A., 1995. Effect of metabolic sensitivity to environmental variation on growth and reproductive potential in tadpole shrimp Triops longicaudatus. Biological Bulletin 189:22-28.
Snyder, G. K., B. Sheafor, D. A. Scholnick and C. Farrelly, 1995. Gas exchange in the insect tracheal system. Journal of Theoretical Biology, 172:199-207.
Scholnick, D. A., 1994. Seasonal variation and diurnal fluctuation in ephemeral desert pools. Hydrobiologia, 294:111-116.
Scholnick, D. A., G. K. Snyder and A. R. Spell, 1994. Acid-base status of a pulmonate land snail (Helix aspersa) and a prosobranch amphibious snail (Pomacea bridgesi) during dormancy. Journal of Experimental Zoology, 268:293-298.
Scholnick, D. A. and C. P. Mangum, 1991. Sensitivity of hemoglobins to intracellular
effectors: Primitive and derived features. Journal of Experimental Zoology, 259:32-42.
Abstracts and Presentations
* Indicates undergraduate research student
- Scholnick, D.A., R.V. Manivanh*, and W.N. Nelson*. 2010. Effects of malaria infection on post-exercise thermoregulation and metabolism in the western fence lizard, SICB Annual Meeting, Seattle. SICB Annual Meeting, Seattle, P2.141.
- Scholnick, D. A., V.N. Haynes*, and G. Nyerges. 2010. Influence of hypoxia on Psychrobacter levels in the Dungeness crab, Cancer magister. Integrative and Comparative Biology, SICB Annual Meeting, Seattle, P3.60.
- Scholnick, D. A., R. Manivanh* and O. Savenkova*. 2009. The physiological consequence of malaria infection in the Western fence lizard, Sceloporus occidentalis. Integrative and Comparative Biology, SICB Annual Meeting, Boston, P1.108.
- Scholnick, D. A., V. Haynes*, and M. Schweitzer*, 2009. Hypoxia impairs antibacterial defense in the Dungeness crab, Cancer magister. Integrative and Comparative Biology, SICB Annual Meeting, Boston, P3.101.
- Scholnick, D. A. and L. E. Burnett, 2005. Respiratory responses to bacterial exposure in the penaeid shrimp Litopenaeus vannamei during locomotory activity and recovery. Integrative and Comparative Biology PI.73.
- Burnett, L., D. Scholnick and K. Burnett. 2005. Impact of bacterial infection on respiratory function in the penaeid shrimp Litopenaeus vannamei. FASEB Journal 19 (4, Suppl. S, Part 1), A648.
- Scholnick, D. A., K. G. Burnett, and L. E. Burnett. 2004. Impact of bacterial infection on respiratory function in the penaeid shrimp Litopenaeus vannamei. Integrative and Comparative Biology P1.73:331.
- Scholnick, D. A. and A. Barabas*. 2003. The effects of chloride on marine decapod crustaceans. Integrative and Comparative Biology 42:1307.
- Petersen*, A., D. A. Scholnick and T. T. Gleeson, 2002. The effect of oxygen and adenosine on lizard thermoregulation. American Zoologist 41:340.
- Wallert, M. A., J. D. Foster, D. A. Scholnick, S. M. Olmschenk, R. J. Kuehn, J. J. Provost, 2001. Kinetic Analysis of Glucose 6-Phosphatase: An investigative Approach to Carbohydrate metabolism and kinetics. FASCB proceedings.
- Scholnick, D. A., L. M. Waters and A. L. Wolf*, 1999. The physiological consequences of claw autotomy in the stone crab Menippe mercenaria. American Zoologist 72A.
- Scholnick, D. A. and T. T. Gleeson, 1998. Effects of prior exercise on metabolic recovery in the lizard Dipsosaurus dorsalis. American Zoologist 37:140A.
- Gleeson, T. T., R. B. Weinstein and D. A. Scholnick, 1996. Influence of adrenal and pancreatic hormones on metabolic recovery from exhaustive exercise in an ectothermic vertebrate. The Physiologist, 39:A-26.
- Scholnick, D. A. and T. T. Gleeson, 1996. Regulation of post-exercise skeletal muscle metabolism by fructose-2,6-bisphosphate and glucagon. The Physiologist, 39:A-26.
- Scholnick, D. A. and T. T. Gleeson, 1995. Regulation of skeletal muscle metabolism in the lizard Dipsosaurus dorsalis by fructose-2,6-bisphosphate. American Zoologist, 35:99A.
- Scholnick, D. A., 1994. Physiological and behavioral response of the tadpole shrimp Triops longicaudatus to hypoxia. American Zoologist, 34:32A.
- Scholnick, D. A., 1993. Effect of fluctuations of O2, temperature and pH on metabolism and growth rates of tadpole shrimp. American Zoologist, 33:49A.