Location: Bowdoin / Hadley W. Horch


Hadley Horch

Associate Professor of Biology and Neuroscience
Director of Neuroscience Program

Contact Information


Druckenmiller Hall - 130E

Teaching this semester

BIOL 1109. Scientific Reasoning in Biology

Pamela Bryer Hadley Horch
Lectures examine fundamental biological principles, from the sub-cellular to the ecosystem level with an emphasis on critical thinking and the scientific method. Laboratory sessions will help develop a deeper understanding of the techniques and methods used in the biological science by requiring students to design and conduct their own experiments. Lecture and weekly laboratory/discussion groups. To ensure proper placement, students must take the biology placement examination and must be recommended for placement in Biology 1109.

BIOL 2135 / NEUR 2135. Neurobiology

Hadley Horch
Examines fundamental concepts in neurobiology from the molecular to the systems level. Topics include neuronal communication, gene regulation, morphology, neuronal development, axon guidance, mechanisms of neuronal plasticity, sensory systems, and the molecular basis of behavior and disease. Weekly lab sessions introduce a wide range of methods used to examine neurons and neuronal systems.

hadley horch


  • B.A., Biology Swarthmore College, 1993
  • PhD, Neurobiology, Duke University, 2001
  • Post-doctoral education, Department of Neurobiology and Behavior, Cornell University, 2001-2002

Teaching Area

  • Molecular Neuroscience

Research Interests

The Horch lab uses the cricket model system to examine the molecular neurobiological basis of a number of areas including regeneration, behavior, and development. Mainly, the lab will focus on the regeneration of interneurons in the auditory system of the cricket. Removing one ear induces auditory interneurons to sprout new dendrites, grow abnormally across the mid-line, and form synapses with intact auditory neurons from the opposite ear, both in developing as well as adult crickets. This is one of the most elegant and complex examples of neuronal regeneration known. Techniques such as dextran backfills, immunohistochemistry, and confocal microscopy will be used to understand the molecular cues involved in this phenomenon. Other projects include examining the role of octopamine on male cricket aggression and attempting to create transgenic crickets in order to examine the development of individual neurons.

Horch, H.W., Sheldon, E., Cutting, C.C., Williams, C.R., Riker, D.M., Peckler, H.R., and Sangal, R.B. 2011. Bilateral consequences of chronic unilateral denervation in the auditory system of the cricket Gryllus bimaculatus. Developmental Neuroscience, 33: 21-37.

Horch, H.W., McCarthy, S.S., Johansen, S.L., and Harris, J.M. 2009.  Differential gene expression during compensatory sprouting of dendrites in the auditory system of the cricket Gryllus bimaculatus. Insect Molecular Biology, 18: 483-496.

Maynard, K.M., McCarthy, S.S., Sheldon, E., Horch, H.W. 2007.  Developmental and adult expression of sempahorin 2a in the cricket Gryllus bimaculatus.  Journal of Comparative Neurology. 503: 169-181.

Horch, H.W.  2004.  Local effects of BDNF on dendritic growth.  Reviews in the Neurosciences, 15: 116-129.

Horch, H.W. and Katz, L.C. 2002.  BDNF release from single cells elicits local dendritic growth in nearby neurons. Nature Neuroscience, 5: 1177-1184.

Horch, H.W., Kruttgen, A., Portbury, S.D, and Katz, L.C. 1999. Destabilization of cortical dendrites and spines by BDNF. Neuron, 23: 353-364.

Horch, H.W., and Sargent, P.B. 1996. Effects of denervation on acetylcholine receptor clusters on frog cardiac ganglion neurons as revealed by quantitative laser scanning confocal microscopy. J. Neurosci. 16(5): 1720-1729.

Horch, H.W., and Sargent, P.B. 1996. Synaptic and extrasynaptic distribution of two distinct populations of nicotinic acetylcholine receptor clusters in the frog cardiac ganglion. J. Neurocytol. 25: 67-77.

Horch, H.W., and Sargent, P.B. 1995. Perisynaptic surface distribution of multiple classes of nicotinic acetylcholine receptors on neurons in the chicken ciliary ganglion. J. Neurosci. 15(12): 7778-7795.