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 1080. Mechanisms of Neurological Disorders

Hadley Horch Christoph Straub
Neurological disorders—such as Alzheimer’s disease, Parkinson’s disease, or autism—are on the rise as human life expectancy increases. First addresses the clinical manifestation of different neurological disorders, and then explores the underlying affected brain regions focusing on how dysfunctions in biological mechanisms lead to disease. Also includes discussions on treatment options and ethical aspects of neurological disorders.

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.

BIOL 2553 / NEUR 2553. Neurophysiology

Hadley Horch Christoph Straub
A comparative study of the function of the nervous system in invertebrate and vertebrate animals. Topics include the mechanism that underlie both action potentials and patterns of spontaneous activity in individual nerve cells, interactions between neurons, and the organization of neurons into larger functional units. Lectures and four hours of laboratory work per week.

BIOL 3329 / NEUR 3329. Neuronal Regeneration

Hadley Horch
The consequences of neuronal damage in humans, especially in the brain and spinal cord, are frequently devastating and permanent. Invertebrates, on the other hand, are often capable of complete functional regeneration. Examines the varied responses to neuronal injury in a range of species. Topics include neuronal regeneration in planaria, insects, amphibians, and mammals. Students read and discuss original papers from the literature in an attempt to understand the basis of the radically different regenerative responses mounted by a variety of 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.