Nicholas J. Strausfeld, Ph.D.

Nicholas J. Strausfeld, Ph.D.'s picture
Regents Professor

Telephone: 

(520) 621-8382

Office: 

Gould-Simpson Rm 415

Areas of research pursued in my laboratory focus on the function and evolution of brains, with the aim of identifying evolutionarily conserved ground patterns of neuronal organization that variously mediate visual perception, allocentric memory, and the control of behavioral repertoires.

Degree(s): 

Ph.D. 1968, University College, London

 

Curriculum vitae

Research Interests: 

Areas of research pursued in my laboratory focus on the function and evolution of brains, with the aim of identifying evolutionarily conserved ground patterns of neuronal organization that variously mediate visual perception, allocentric memory, and the control of behavioral repertoires.

Arthropoda is the most species-rich phylum, and offers enormous challenges to systematists, both in resolving taxonomic relationships within this group and reconstructing their evolutionary history. Hypotheses about the relationships amongst the major arthropod clades have traditionally used morphological characters, mostly external, for developing ideas about which taxa are related through common ancestry. In recent years, the ascendance of molecular phylogenomics, which relies on molecular sequence data to infer evolutionary relationships, has all but displaced morphology-based studies. However, beginning in my laboratory in 1995, comparisons of brain organization have demonstrated that remarkably consistent morphological ground patterns exist within certain groups, irrespective of great differences in external morphologies. Because neural architectures are so highly conserved, they can be used for deriving phylogenetic relationships. Hennigian neural cladistics provides a neutral route to resolving such relationships. Defined structural features (characters), such as neurofibrillar architectures, types of tracts, types and boundaries of neuropils, cell body arrangements, and many more features, can each be scored as present or absent in some 75 taxa representing most arthropod groups, along with outgroups belonging to the Phylum Lophotrochozoa. Using computational tools, such as PAUP (Phylogenetic Analysis Using Parsimony), it is possible to infer relatedness among taxa and to interrogate relational trees (cladograms) to determine whether characters, or clusters of characters, have evolved by convergence or whether they share genealogical correspondence (homology). Importantly, neural cladistics supports the view that Hexapoda originated from a malacostracan-like ancestor. So do molecular results published recently in other laboratories, and our own, using molecular sequence data or expressed sequence tags.

These strategies are invaluable for investigating across the arthropods the occurrence of neural arrangements that have been studied in great detail in one exemplary species, such as Drosophila, in order to determine if such arrangements are novelties or ancestral. Hennigian neural cladistics challenges some common assumptions, one being that a group of morphologically simple crustaceans known as branchiopods gave rise to the hexapods. Branchiopods have very simple brains and possess only two optic neuropils in contrast to the three or more nested optic neuropils of insect and malacostracan crustaceans. Positing a branchiopod-like ancestry implies that similarities of brain organization in insects and malacostracans have evolved convergently. Recent evidence from the lower Cambrian, resolving a fossil arthropod with a preserved nervous system, shows that arthropod stem taxa possessed compound eyes supplying three nested optic neuropils even before the appearance of the first branchiopods. This alone suggests that many of the circuits observed in the optic centers of recently evolved taxa, such as Drosophila, are likely to have been inherited, largely unchanged for over 500 million years.

Theodosius Dobzhansky (1900-1975), one of the founders of the modern evolutionary synthesis, insisted "Nothing in biology makes sense except in the light of evolution." This dictum also resonates in my laboratory's more mundane research on the structure and function of brain centers, such as the paired mushroom bodies and their crustacean homologues, or the midline neuropils of the insect and crustacean central complex, and their arachnid homologues. Slowly, but surely, the view that arthropods have simple brains is being displaced by a growing body of knowledge that it is anything but: the elaborate organization of the arthropod brain suggests circuits and functions typifying the brains of vertebrates. If such organizations can be shown to be homologous across phyla, that would imply that, in the depth of time, the ancestor of vertebrates, arthropods and lophotrochozoans possessed a ground pattern of circuits that are essential to memory formation and behavioural choice.

Career

Dr. Strausfeld graduated from University College London, where he also received his Ph.D. in 1968. He joined the Max Planck Institute for Biological Cybernetics in 1970 and then moved to the European Molecular Biology Laboratory as a group leader in 1975. After habilitating at the University of Frankfurt in 1986, he was appointed Full Professor in the Division of Neurobiology at the University of Arizona and became a Regents' Professor in 1999.  In 2002 he was elected a Fellow of the Royal Society of London. He received a John Simon Guggenheim Memorial Foundation Fellowship in 1994, a John D. and Catherine T. MacArthur Foundation Fellowship in 1995, an Alexander von Humboldt Senior Research Prize in 2001, and a Volkswagen Stiftung Visiting Professorship in 2009. Currently Dr. Strausfeld is a Regents' Professor in the Department of Neuroscience and is the Director of the University of Arizona's Center for Insect Science.

 

Selected Publications: 

Ma X-Y, Hou X, Edgecombe GD, Strausfeld NJ. 2012. Complex brain and optic lobes in an early Cambrian arthropod. Nature, in press

Strausfeld NJ. 2012. Arthropod Brains: Evolution, Functional Elegance, and Historical Significance. Harvard University Press, Cambridge, MA, 821 pp.

Lin C, Strausfeld NJ. 2012. Visual inputs to the mushroom body calyces of the whirligig beetle Dineutus sublineatus: modality switching in an insect. J Comp Neurol 520:2562-2574. doi: 10.1002/cne.23158.

Mu L, Ito K, Bacon JP, Strausfeld NJ. 2012. Optic glomeruli and their inputs in Drosophila share an organizational ground pattern with the antennal lobes. J Neurosci 32:6061-6071. PMID: 22553013

Wolff G, Harzsch S, Hansson BS, Brown S, Strausfeld N. 2012. Neuronal organization of the hemiellipsoid body of the land hermit crab, Coenobita clypeatus: correspondence with the mushroom body ground pattern. J Comp Neurol 520:2824-2846. doi: 10.1002/cne.23059.

Phillips-Portillo J, Strausfeld NJ. 2012. Representation of the brain's superior protocerebrum of the flesh fly, Neobellieria bullata, in the central body. J Comp Neurol 520:3070-3087. doi: 10.1002/cne.23094.

Andrew DR, Brown SM, Strausfeld NJ. 2012. The minute brain of the copepod Tigriopus californicus supports a complex ancestral ground pattern of the tetraconate cerebral nervous systems. J Comp Neurol 520:3446-3470. doi: 10.1002/cne.23099.

Strausfeld NJ, Andrew DR. 2011. A new view of insect-crustacean relationships I. Inferences from neural cladistics and comparative neuroanatomy. Arthropod Struct Dev 40:276-288. PMID: 21333750

Strausfeld NJ. 2010. Brain homology: Dohrn of a new era? Brain Behav Evol 76:165-7. PMID: 21196694

Strausfeld NJ 2010. Neurons and circuits that contribute to the detection of directional motion across the retina of the fly. Handbook of Brain Microcircuits. Eds: Gordon M. Shepherd and Sten Grillner. Oxford University Press.

Strausfeld NJ. 2009. Brain organization and the origin of insects: an assessment. Proc Biol Sci 276:1929-1937. PMID: 19324805.

Strausfeld NJ, Sinakevitch I, Brown SM, Farris SM. 2009. Ground plan of the insect mushroom body: functional and evolutionary implication. J Comp Neurol 513:265-291. PMID: 19152379