ZEBRAFISH RESEARCH AT UCL ucl logo click to visit home page
NEWS

Anukampa Barth

Post Doc
a.barth@ucl.ac.uk
020 3549 5642 (t)
33343 (internal)

From Asymmetric Neuroanatomy to Lateralised Behaviour

My interest lies in understanding the functional significance of the observed neuroanatomical asymmetries in the vertebrate CNS, and how these asymmetries are linked to lateralised behaviour. My goal is to establish causal relationships between the lateralisation of the epithamalus, its afferent and efferent projections and animal behaviour using genetic, molecular and laser-ablation approaches to manipulate lateralised habenular circuitry and subsequently test animals in our behavioural assays.

In humans, neuroanatomical asymmetries are reflected in the specialised functional abilities residing in the left and right brain hemispheres. The importance of these brain asymmetries is underscored by the fact that several neuropathologies such as autism, dyslexia, schizophrenia and Alzheimer's disease are linked to changes in neuroanatomical asymmetries. Lateralised behaviours, such as handedness in humans and eye preference for prey and predator detection in amphibians is widespread throughout the animal kingdom and even found among invertebrates such as c.elegans and Drosophila.

For many years, our lab has been characterising the asymmetries in the epithalamus (for details see The Asymmetric Brain link). The habenular nuclei are part of a highly conserved limbic system circuit involved in modulating a wide variety of behaviours including anxiety, aggression, and sleep and memory formation. Are the epithalamic asymmetries we observe linked to lateralised behaviour? Due to the conserved nature of the limbic system, we believe that the insights gained in the zebrafish will help to understand functional relationships of neuro-circuitry in higher vertebrates.

This project was initiated in collaboration with Richard Andrew's group at the University of Sussex, and we have previously shown that young larval zebrafish show a lateralization of eye preference when viewing a conspecific (for example their own reflection). Interestingly, the orientation of this bias is reversed in fsi (frequent-situs-inversus) mutant fry that show reversal of epithalamic asymmetries. These ‘reversed' fry also show a ‘bolder' and more exploratory behaviour (Barth et al, 2005).

The initial tests focused on young zebrafish larvae (fry) with genetically reversed epithalamic asymmetries (fsi); I have now extended the analysis to fry with other genetically or experimentally altered epithalamic asymmetries, for example fry with more symmetric habenulae and efferent neuronal circuitry.

I aim to closely dissect the circuitry of fry that show either strong or no lateralized behaviours. Such detailed analysis will help us to understand how complex behaviours are formed and how only slight changes in connectivity can affect the behavioural outcome, making some individual animals more bold and others more anxious. The results will contribute to our understanding of behavioural drives, and might help to shed light on behavioural patterns that are seen in Humans.

In addition, new tests are being devised to address other aspects of behaviour such as sleep and memory formation. The lab is currently undertaking an ENU mutagenesis screen for asymmetry/laterality mutants. Some of these fry are viable and will be used for behavioural testing.







(left panel) In Situ Hybridisation of normal and fsi embryos reversals that visceral asymmetries such as heart looping are reversed in fsi embryos; (right panel) brain asymmetries such as the position of the parapineal (pp) are reversed as well









(left panel) Reversal of parapineal position can be visualised in living fsi x tg(foxd3:GFP) transgenic embryos; (right panel) using lipophilic dyes we show that the dorso-ventral segregation of habenular efferent projections is reversed in fsi fry with reversed pp position. (see Barth et al, 2005 for details)



CV/HISTORY

My initial studies were orientated towards molecular biology and early mouse development; for my PhD I analysed a mutation affecting gastrulation in the mouse in Liz Robertson's lab at Columbia University, USA.

I began my post-doctoral career with Steve Wilson quite a few years ago. Over the years my interests morphed from studying early patterning of the neural plate and the forebrain to CNS asymmetry, and finally on to my current incarnation as a behavioural neurobiologist.

PhDDept of Genetics & Development; Columbia University, New York
BScFreie Universitaet Berlin, Germany
Exchange Student & Research AssistantVanderbilt University, Nashville, USA
PhD StudentColumbia University, New York, USA
Research FellowKing's College London, UK
Senior Research FellowCurrent: University College London, UK

SELECTED PUBLICATIONS

Barth,A., Miklosi,A., Watkins,J., Bianco,I.H., Wilson,S.W., Andrew,R.J. (2005)
fsi Zebrafish Show Concordant Reversal of Laterality of Viscera, Neuroanatomy, and a Subset of Behavioral Responses.
Current Biology 15:844-850
click to download pdf

Mathieu,J., Barth,A., Rosa,F.M., Wilson,S.W., Peyrieras,N. (2002)
Distinct and cooperative roles for Nodal and Hedgehog signals during hypothalamic development.
Development 129:3055-3065
click to download pdf

Houart,C., Caneparo,L., Heisenberg,C., Barth,K.A., Take-Uchi,M., Wilson,S.W. (2002)
Establishment of the telencephalon during gastrulation by local antagonism of Wnt signaling.
Neuron 35:255-265
click to download pdf

Rohr,K.B., Barth,K.A., Varga,Z.M., Wilson,S.W. (2001)
The nodal pathway acts upstream of hedgehog signaling to specify ventral telencephalic identity.
Neuron 29:341-351
click to download pdf

Shanmugalingam,S., Houart,C., Picker,A., Reifers,F., Macdonald,R., Barth,A., Griffin,K., Brand,M., Wilson,S.W. (2000)
Ace/Fgf8 is required for forebrain commissure formation and patterning of the telencephalon.
Development 127:2549-2561
click to download pdf

Barth,K.A., Kishimoto,Y., Rohr,K.B., Seydler,C., Schulte-Merker,S., Wilson,S.W. (1999)
Bmp activity establishes a gradient of positional information throughout the entire neural plate.
Development 126:4977-4987
click to download pdf

Masai,I., Heisenberg,C.P., Barth,K.A., Macdonald,R., Adamek,S., Wilson,S.W. (1997)
floating head and masterblind regulate neuronal patterning in the roof of the forebrain.
Neuron 18:43-57
click to download pdf

Kazanskaya,O.V., Severtzova,E.A., Barth,K.A., Ermakova,G.V., Lukyanov,S.A., Benyumov,A.O., Pannese,M., Boncinelli,E., Wilson,S.W., Zaraisky,A.G. (1997)
Anf: a novel class of vertebrate homeobox genes expressed at the anterior end of the main embryonic axis.
Gene 200:25-34
click to download pdf

Barth,K.A., Wilson,S.W. (1995)
Expression of zebrafish nk2.2 is influenced by sonic hedgehog/vertebrate hedgehog-1 and demarcates a zone of neuronal differentiation in the embryonic forebrain.
Development 121:1755-68
click to download pdf

Macdonald,R., Barth,K.A., Xu,Q., Holder,N., Mikkola,I., Wilson,S.W. (1995)
Midline signalling is required for Pax gene regulation and patterning of the eyes.
Development 121:3267-78
click to download pdf

Macdonald,R., Xu,Q., Barth,K.A., Mikkola,I., Holder,N., Fjose,A., Krauss,S., Wilson,S.W. (1994)
Regulatory gene expression boundaries demarcate sites of neuronal differentiation in the embryonic zebrafish forebrain.
Neuron 13:1039-1053
click to download pdf



University College London - Gower Street - London - WC1E 6BT - Telephone: +44 (0)20 7679 2000 - Copyright © 1999-2009 UCL


Search by Google