Hadley Horch

Professor Horch's research focuses on how neurons in adult invertebrates recover from injury. Unlike many neuronal systems, the auditory system of the cricket demonstrates robust neuronal growth in response to denervation.  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.  Currently, students in my lab are using molecular biology to clone the genes for guidance cues from crickets.  We hope to examine the expression of these cues to assess if they might be involved in this regeneration.  We are also examining the 3-dimensional characteristics of these regenerated neurons.  The lab regularly uses techniques such as dye backfills, immunohistochemistry, in situ hybridization, PCR, and confocal microscopy.  We are also attempting to develop a method for transfecting living neurons in crickets. 

News

• Six Women Scientists Receive Prestigious External Grants in Spring Semester, Bowdoin News (October 25, 2018)
• Sarah and James Bowdoin Day 2017, Bowdoin News (October, 2017) 
• Professor Horch on Why Crickets Matter, Bowdoin News (May 1, 2017)

Sample Student Lab Research

The Neuroscience department awards its outstanding students with the opportunity to do serious lab research over the Summer. Stipends are available and projects are often co-authored for publication. This Summer has again yielded outstanding original research in the filed. Here are some sample projects:

Recent honors theses

Alicia Edwards
Semaphorin-induced plasticity in the nervous system of the cricket, Gryllus bimaculatus.

Samuel Brill-Weil
That’s DOPE: The delayed onset, prolonged excitation response of a primary auditory interneuron in Gryllus bimaculatus.

Felicia Wang
Differential gene expression during compensatory plasticity in the prothoracic ganglion of the cricket, Gryllus bimaculatus.

Julie Scholes
Characterization of negative phonotactic behavior in the adult cricket, Gryllus bimaculatus.

Jack Moynihan
Using a combined physiological recording and electrophoretic staining technique to better understand compensatory plasticity in Gryllus bimaculatus.

John Pietro
The role of dscam2 in neuronal regeneration in the auditory system of the common field cricket Gryllus bimaculatus.

Shannon Knight
Determining the role of semaphorin proteins in the compensatory growth 
observed in adult Gryllus bimaculatus.

Maddie Rutan
Effect of injury on alternative polyadenylation of neuronal 
synaptobrevin in the cricket, Gryllus bimaculatus.

John Hobbs 
The effects of hormones on the sexual dimorphic auditory dendritic compensatory regeneration of the Cricket Gryllus bimaculatus.

Adam Zhang 
Quantifying Changes in Semaphorin Expression after Deafferentation in Gryllus Bimaculatus.

Prasad, M., Detchou, D., Wang, F., Kingston, S., Ledwidge, L. Horch, H.W. 2021. Transcriptional expression changes during compensatory plasticity in the terminal ganglion of the adult cricket Gryllus bimaculatus. BMC Genomics 22, 742. https://doi.org/10.1186/s12864-021-08018-x

Horch, H.W., Spicer, S., Low, I.I.C, Joncas, C. Quenzer, E., Okoya H., Ledwidge, L.M., Fisher H. 2020. Characterization of plexinA and two distinct semaphorin1a transcripts in the developing and adult cricket Gryllus bimaculatus. J Comp Neurol. 528: 687-702. Doi: 10.1002/cne.24790. PMID: 31621906

Barry, S. K., Nakamura, T., Matsuoka, Y., Straub, C., Horch, H. W., Extavour, C. G. Injecting Gryllus bimaculatus Eggs. J. Vis. Exp. (150), e59726, doi:10.3791/59726 (2019). 

Fisher, H.P., Pascual, M.G., Jimenez, S, Michaelson, D.A., Joncas, C.R., Quenzer, E. D., Christie, A.E., and Horch, H.W. 2018. De novo assembly of a transcriptome from adult Gryllus bimaculatus prothoracicganglia: An invertebrate model for investigating central nervous systemcompensatory plasticity. PLoS One e0199070. PMID: 29995882

Horch, H.W., Pfister A., Ellers, O., Johnson, A.S. Plasticity in the cricket central nervous system. 2017. In: Cricket as a Model Organism:Development, Regeneration, and Behavior. pp 105-128. Edited by Hadley Wilson Horch, Taro Mito, Aleksandar Popadic, Hideyo Ohuchi, Sumihare Noji.Springer (New York, Heidelberg). 2017.

Horch, H. W. Liu, J., Mito, T., Popadic, A., and Watanabe, T.Protocols in the Cricket. 2017. In: Cricket as a Model Organism: Development, Regeneration, and Behavior. Pp 327-370. Edited by Hadley Wilson Horch, Taro Mito, Aleksandar Popadic, Hideyo Ohuchi, Sumihare Noji..Springer (New York, Heidelberg).

Pfister A, Johnson A, Ellers O and Horch HW. 2013. Quantification ofdendritic and axonal growth after injury to the auditory system of the adult cricket Gryllus bimaculatus. Front. Physiol. 3:367. doi:10.3389/fphys.2012.00367

Zeng, V., Ewen-Campen, B., Horch, H.W., Roth, S., Noji, S., and Extavour, C.G.2013. Gene discovery in a hemimetabolous insect: a de novo transcriptome for the cricket Gryllus bimaculatus. PLoS ONE 8(5): e61479 PMID: 23671567

Watanabe, T., Ochiai, H, Sakuma, T., Horch, H.W., Hamaguchi, N., Nakamura, T., Bando, T., Ohuchi, H., Yamamoto, T., Noji, S., and Mito, T.2012. Non-transgenic genome modifications in a hemimetabolous insect using zinc-finger and TAL effector nucleases. Nature Commun. 3:1017; PMID: 22910363.

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.