A longstanding line of research in our lab is to reconstruct how lineages assemble the major circuits of the fly brain. For the small larval brain, this reconstruction can now be done at a so far unparalleled level of resolution, using a series of several thousand contiguous electron microscopic sections in conjunction with a specially developed software package that allows us to assign all synapses to specific neurons and their lineages.
More recently, we have identified a specific circuit, called the anterior visual pathway (AVP), which conducts input form the eye to a brain center, the central complex, known to process and store visual information in order to control fly locomotion (walking, flight). The central part of this circuit is formed by three lineages, whose neurons form several classes of highly ordered parallel and sequential elements. We are investigating the function of the neuronal classes of the AVP, by recording their activity in response to defined visual stimuli, and follow the question of how the developmental history of a neuron (time of birth, placement within the spatial framework of the developing brain) relates to its later connectivity within the AVP circuit.
We conduct research contributing to our understanding of the genetic specification of brain circuitry. During the course of its proliferation, each neuroblast expresses characteristic sets of regulatory genes. These genes are assumed to be relevant in the control of the wiring properties of the neurons born from a particular neuroblast during a particular time interval. Our research aims to link the structurally defined lineages mapped in the larval brain with the neuroblasts of the embryo, using a technique that systematically labels all transcription factors expressed in neuroblasts and then follows the expression of these genes from neuroblast to lineage.
Finally, our work on the genetic patterning of the Drosophila brain guided us towards becoming more active in comparative studies, addressing questions of stem cells and neural development in other animal taxa. We decided to focus on several clades of basal metazoan, notably the flatworms (platyhelminthes) and acoels, generally considered to be the most primitive animals with a central nervous system, as well as cnidarians, which predate bilaterian animals.
Kendroud S, Bohra AA, Kuert PA, Nguyen B, Guillermin O, Sprecher SG, Reichert H, VijayRaghavan K, Hartenstein V., "Structure and development of the subesophageal zone of the Drosophila brain. II. Sensory compartments", J Comp Neurol 526: 33-58 (2018).
Hartenstein V, Omoto JJ, Ngo KT, Wong D, Kuert PA, Reichert H, Lovick JK, Younossi-Hartenstein A. , "Structure and development of the subesophageal zone of the Drosophila brain. I. Segmental architecture, compartmentalization, and lineage anatomy", J Comp Neurol 526: 6-32 (2018).
Boyan G, Liu Y, Khalsa SK, Hartenstein V., "A conserved plan for wiring up the fan-shaped body in the grasshopper and Drosophila", Dev Genes Evol 227: 253-269 (2017).
Hartenstein V, Takashima S, Hartenstein P, Asanad S, Asanad K., " bHLH proneural genes as cell fate determinants of entero-endocrine cells, an evolutionarily conserved lineage sharing a common root with sensory neurons", Dev Biol 431: 36-47 (2017).
Lovick JK, Omoto JJ, Ngo KT, Hartenstein V., "Development of the anterior visual input pathway to the Drosophila central complex", J Comp Neurol 525: 3458-3475 (2017).
Ngo KT, Andrade I, Hartenstein V., "Spatio-temporal pattern of neuronal differentiation in the Drosophila visual system: A user's guide to the dynamic morphology of the developing optic lobe", Dev Biol 428: 1-24 (2017).
Omoto JJ, Keles MF, Nguyen BM, Bolanos C, Lovick JK, Frye MA, Hartenstein V., "Visual Input to the Drosophila Central Complex by Developmentally and Functionally Distinct Neuronal Populations", Curr Biol 27: (2017).
Hartenstein, V, "The Central Nervous System of Invertebrates", The Wiley Handbook of Evolutionary Neuroscience 173-235 (2017).
Hartenstein V, Cruz L, Lovick JK, Guo M., "Developmental analysis of the dopamine-containing neurons of the Drosophila brain", J Comp Neurol 525: (2017).
Hartenstein, V., "Platyhelminthes", Structure and evolution of invertebrate nervous systems (2016).
Omoto JJ, Lovick JK, Hartenstein V., "Origins of glial cell populations in the insect nervous system", Curr Opin Insect Sci 18: (2016).
Joly JS, Recher G, Brombin A, Ngo K, Hartenstein V., "A Conserved Developmental Mechanism Builds Complex Visual Systems in Insects and Vertebrates", Curr Biol 26: R1001-R1009 (2016).
Aghajanian P, Takashima S, Paul M, Younossi-Hartenstein A, Hartenstein V., "Metamorphosis of the Drosophila visceral musculature and its role in intestinal morphogenesis and stem cell formation", Dev Biol 420: (2016).
Gold DA, Nakanishi N, Hensley NM, Hartenstein V, Jacobs DK., "Cell tracking supports secondary gastrulation in the moon jellyfish Aurelia", Dev Genes Evol 226: (2016).
Takashima S, Aghajanian P, Younossi-Hartenstein A, Hartenstein V., "Origin and dynamic lineage characteristics of the developing Drosophila midgut stem cells", Dev Biol 416: (2016).