Ernst-August Seyfarth
Apl. Professor (retired)

Recent Research Projects

1. Cellular Mechanisms of Mechanoreception

Two unresolved problems in the study of mechanoreception are how mechanical stimuli are transduced into an electrical signal, and how the dynamic properties of different mechanoreceptors are controlled. We use isolated preparations of lyriform slit sensilla from the spider leg to study fundamental mechanisms of mechanosensory transduction and adaptation in identified neurons. Recently, we have also examined the complex efferent innervation of the sensory neurons in slit sensilla. A related project deals with the function and evolution of auditory systems in vertebrates and insects (in cooperation with M. Kössl).

The techniques applied in these projects are mainly electrophysiological (such as intracellular recordings of membrane potential and current) but also involve anatomical methods (immunocytochemistry and electron microscopy).

2. Neuroethology of a Simple Behavior in Spiders

We examine the neuronal substrates and mechanisms responsible for relatively simple behaviors of spiders. In Cupiennius salei, a large tropical hunting spider (of which we keep a long-term breeding colony), stimulation of tactile hairs evokes reflex activity in several leg muscles. Coordinated contraction of these muscles raises the body - as in doing push-ups.

Using this reliable reaction we search for the neuronal circuitry underlying body raising behavior. Electrophysiological recordings from particular leg muscles and from single, identifiable neurons in the leg ganglia have revealed interneurons whose (electrical) activation causes the muscle reflexes. Depending on the exact stimulus situation, we have found local and plurisegmental responses and activation of local and plurisegmental interneurons. The results provide a first glimpse of the architecture of particular sensory-motor elements in the fused central nervous system of spiders.

3. Case Studies in the History of Neurobiology

Neuroscience research has flourished over the last few decades. While there are reports of breakthrough discoveries almost every month, the interdisciplinary roots and the intellectual history of neurobiology as a whole tend to be ignored or even forgotten. We think that case-studies, retracing and documenting the life and work of key figures in the field, are especially suited to illuminate important historical developments. Recently we have paid particular attention to the contributions and biographies of neuroscientists who were persecuted during the Nazi rule in Central Europe and were forced to pursue a new career abroad.

Publications

Huckstorf K, Kosok G, Seyfarth E-A, Wirkner CS (2012) The hemolymph vascular system in Cupiennius salei (Araneae: Ctenidae). Zool Anzeiger (in the press). http://dx.doi.org/10.1016/j.jcz.2012.03.004

Möckel, D.; Seyfarth. E.-A.; Kössl, M. (2011) Otoacoustic emissions in bushcricket ears: general characteristics and the influence of the neuroactive insecticide pymetrozine. J Comp Physiol A197: 193-202

Loesel, R.; Seyfarth, E.-A.; Bräunig, P.; Agricola, H.-J. (2011) Neuroarchitecture of the arcuate body in the brain of the spider Cupiennius salei (Araneae, Chelicerata) revealed by allatostatin-, proctolin-, and CCAP-immunocytochemistry and its evolutionary implications. Arthropod Struct Dev 40(3): 210-20 (2011).

Kössl, M. ; Möckel, D. ; Weber, M. ; Seyfarth, E.-A. (2008):
Otoacoustic emissions from insect ears: evidence of active hearing?
J Comp Physiol A 194: 597-609.

Möckel, D. ; Seyfarth, E.-A. ; Kössl, M. (2008):
Sources of otoacoustic emissions from tympanal organs in insects.
FENS Abstr 4, 087.13.

Strausfeld, N. J. ; Seyfarth, E.-A. (2008):
Johann Flögel (1834-1918) and the birth of comparative insect neuroanatomy and brain nomenclature.
Arthropod Struct Dev 37: 434-441.

Kössl, M. ; Möckel, D. ; Weber, M. ; Seyfarth, E.-A. (2008):
Schallemissionen aus Insektenohren: Hinweis auf aktives Hören?
Neuroforum 08 (1): 166-173.

Stollewerk, A ; Seyfarth, E.-A. (2008):
Evolutionary changes in sensory precursor formation in arthropods: embryonic development of leg sensilla in the spider Cupiennius salei.
Dev Biol 313: 659-673.

Zottoli, S. J. ; Cioni, C. ; Seyfarth, E.-A. (2007):
Reticulospinal neurons in anamnionic vertebrates: A celebration of Alberto Stefanelli's contributions to comparative neuroscience.
Brain Res Bull 74: 295-306.

Möckel, D. ; Seyfarth, E.-A. ; Kössl, M. (2007):
The generation of DPOAEs in the locust ear is contingent upon the sensory neurons.
J Comp Physiol A 193: 871-879.

Kössl, M. ; Coro, F ; Seyfarth, E.-A. ; Nässig, W. A. (2007):
Otoacoustic emissions from insect ears having just one auditory neuron.
J Comp Physiol A 193: 909-915.

Möckel, D. ; Seyfarth, E.-A. ; Kössl, M. (2007):
Tympanal sensilla generate DPOAEs in the locust ear.
Neuroforum 07 (1): T18-6B.

Möckel, D. ; Kössl, M. ; Seyfarth, E.-A. (2007):
Pymetrozine, a neuroactive insecticide, reduces otoacoustic emissions in the bushcricket ear.
10th Meeting Austrian Neuroscience Association (ANA), Seggauberg: P37.

Weber, M. ; Baumgarten, D. ; Winter; H. ; Kössl, M. ; Seyfarth, E.-A. (2006):
Active hearing in the bushcricket, Mecopoda elongata.
FENS Abstr 3: A 038.24.

Seyfarth, E.-A. (2006):
Albrecht Bethe (1872-1954): comparative physiologist and eminent neurobiologist.
FENS Abstr 3: A 196.11.

Möckel, D. ; Seyfarth, E.-A. ; Kössl, M. (2006):
DPOAEs in the locust depend on the integrity of the sensory organ.
Assoc Res Otolaryngol Abs: 23.

Seyfarth, E.-A. (2006):
Julius Bernstein (1839-1917): pioneer neurobiologist and biophysicist.
Biol Cybern 94 (1): 2-8.

Peichl, L. ; Seyfarth, E.-A. (2006):
Vor 100 Jahren: Nobelpreis für Golgi und Ramón y Cajal.
Neuroforum 06 (4): 266-267.

Weber., M. ; Kössl, M. ; Volknandt, W. ; Seyfarth, E.-A. (2005)
Acetylcholine is a transmitter candidate in sensory neurons of the bushcricket ear (Mecopoda elongata).
Neuroforum 05, (9 Suppl): 94 A.

Loesel, R. ; Strausfeld, N. J. ; Seyfarth, E.-A. ; Agricola, H.-J. (2005):
A 450 million year leitmotif for a locomotor control center in the brain: conserved neuroarchitecture of the central complex of chelicerates and hexapods.
Neuroforum 05, (9 Suppl): 262 A.

French, A. S. ; Torkkeli, P. H. ; Seyfarth, E.-A. (2002):
From stress and strain to spikes: mechanotransduction in spider slit sensilla.
J Comp Physiol A 188: 739-752.

Panek, I. ; French, A. S. ; Seyfarth, E.-A. ; Sekizawa, S. ; Torkkeli, P. H. (2002):
Peripheral GABAergic inhibition of spider mechanosensory afferents.
Eur J Neurosci 16 (1): 96-104.

Fabian-Fine, R. ; Seyfarth, E.-A. ; Meinertzhagen, I. A.(2002):
Peripheral synaptic contacts at mechanoreceptors in arachnids and crustaceans: morphological and immunocytochemical characteristics.
Microsc Res Tech 58 (4): 283-298.

Seyfarth, E.-A. (2002):
Tactile body raising: neuronal correlates of a 'simple' behavior in spiders.
In: Toft, S. ; Scharff, N. (Hrsg.): European arachnology 2000.
(19th European Colloquium of Arachnology Århus 17. - 22.07.2000),
Århus, Aarhus University Press: 19-32.

Seyfarth, E.-A. ; Peichl, L.(2002):
Vor 100 Jahren: Julius Bernstein (1839 - 1917) formuliert seine "Membrantheorie".
Neuroforum 02 (4): 274-276.

Höger, U. ; Seyfarth, E.-A. (2001):
Structural correlates of mechanosensory transduction and adaptation in identified neurons of spider slit sensilla.
J Comp Physiol A 187: 727-736.

Buchholtz, E. A. ; Seyfarth, E.-A. (2001):
The study of "fossil brains": Tilly Edinger (1897-1967) and the beginnings of paleoneurology.
BioScience 51: 674-682.