Anna N. Ahn

Associate Professor of Biology

F. W. Olin Science Center, Room 2375
1250 N. Dartmouth Ave.
Claremont, CA 91711
(909) 607-9122
aahn@hmc.edu

Education & Professional Experience

  • B.A., Integrative Biology, University of California, Berkeley
  • Ph.D., Integrative Biology, University of California, Berkeley
  • Postdoctoral Research Fellow, Harvard University
  • Visiting Scientist, Massachusetts Institute of Technology
  • Visiting Assistant Professor, Harvey Mudd College
  • Assistant Professor of Biology, Harvey Mudd College

Teaching

  • Bio 54: Biology Laboratory
  • Bio 81/82: Human Physiology & Disease
  • Bio 101: Comparative Physiology
  • Bio 103: Physiology Laboratory
  • Bio 183: Topics in Physiology (seminar)
  • Bio/Eng 190B: Biomechanics

Research Interests

Professor Ahn’s research focuses on the neural control and mechanics of animal locomotion. We take an integrative and multi-disciplinary approach to examine the different levels of organization that influence the behavioral output of the neuro-musculo-skeletal system in animals such as frogs, lizards, tarantulas, and even humans! Our work includes examining the neural signals sent to muscles and how the different levels of musculo-skeletal organization respond to these neural signals. By spanning the fields of muscle physiology, biomechanics, and motor control, we hope to discover general principles underlying the neuro-mechanical basis of legged locomotion.

Senior Theses

Shireena Desai ’05: Force-length properties of fast- and slow-twitch muscle under varying stimulation levels in the Desert Iguana (Dipsosaurus dorsalis).

Jae Shin ’05: Conservation of neural control in Anurans during swimming at different speeds.
Alejo Enriquez ’06: Energetic differences between bipedal and quadrupedal locomotion in Dipsosaurus dorsalis.

Trisha Staab ’06: In vivo activity of the iliofibularis muscle during two-legged and four-legged running in the Desert Iguana.

Lauren LaCount ’07: Velocity, acceleration, and cost of activity of bipedal and quadrupedal locomotion in the desert iguana, Dipsosaurus dorsalis

Karla Whitfileld ’10:  Thermal sensitivity of locomotory performance in the tarantula, Aphonopelm hentzi. (co-advised with Adolph)

Nick Booster ’11 (Pitzer):  Effect of temperature on walking kinematics in tarantulas.  (co-advised with Adolph)

Rebecca Salzman ’12 (CMC):  Effect of active and passive components on the kinematics of an intact frog ankle.

Christopher Jerry ’12 (CMC):  The neural control and kinematics of walking in humans.

Lab Members 2012

  • Charlie Brayton ’13 (Chem-Bio)
  • Tania Bhatia ’13 (Scripps)
  • Parker Martin ’13 (Engineering)
  • Rachel Roley ’15 (Engineering)
  • Jennie Tave ’12 (Scripps)

Selected Publications

Ahn AN. in press. How muscle function – the work loop technique. J. Exp. Biol.

Ahn AN, Kang JK*, Quitt MA*, Davidson BD*, Nguyen CT*.  2011.  Variability of neural activation during walking in humans:  Short heels and big calves. Biol. Lett.  doi:10.1098/rsbl.2010.1169 [article]

Wu GC*, Wright JC, Whitaker DL & Ahn AN. 2010. Kinematic evidence for superfast locomotory muscle in two species of teneriffiid mites. J. Exp. Biol.213: 2551-2556. [article]

Nishikawa K, Biewener A, Aerts P, Ahn A et al. 2007.  Neuromechanics: An integrative approach for understand motor control. Integr. Comp. Biol. 47: 16-54. [article]

Ahn AN, Meijer K & Full RJ. 2006. In situ muscle power differs without varying in vitro mechanical properties in two insect leg muscles innervated by the same motor neuron. J. Exp. Biol. 209: 3370-3382. [article]

Biewener AA & Ahn AN. 2006. Tired of fatigue? Factors affecting the force-length relationship of muscle. J. Appl. Physiol. 101: 5-6. [article]

Ahn AN, Furrow E* & Biewener AA. 2004. Walking and running in the red-legged running frog, Kassina maculataJ. Exp. Biol. 207: 399-410. [article]

Ahn AN, Monti RJ & Biewener AA. 2003. In vivo and in vitro heterogeneity of segment length changes in the semimembranosus muscle of the toad. J. Physiol. 549: 877-888. [article]

Ahn AN & Full RJ. 2002. A motor and a brake: two leg extensor muscles acting at the same joint manage energy differently in a running insect. J. Exp. Biol. 205: 379-389. [article]

Full RJ, Stokes DR, Ahn AN & Josephson RK. 1998. Energy absorption during running by leg muscles in a cockroach. J. Exp. Biol201: 997-1012. [abstract | article (pdf)]

Full RJ & Ahn AN. 1995. Static forces and moments generated in the insect leg — comparison of a 3-dimensional musculoskeletal computer-model with experimental measurements. J. Exp. Biol. 198: 1285-1298. [abstract |article (pdf)]

Weinstein RB, Full RJ & Ahn AN. 1994. Moderate dehydration decreases locomotor performance of the ghost crab, Ocypode quadrataPhysiol. Zool.67: 873-891.

* undergraduate author