Neuroscientists from all parts of the Australian National University have provided descriptions of research areas and projects for Honours students. A range of exciting projects are available from the following areas:

The John Curtin School of Medical Research
School of Biochemistry and Molecular Biology
Research School of Biological Sciences

Please take your time to read through this document. Select two or three projects which really interest you and then contact Dr Anna Cowan by phone, (02) 6125 1606/ 58506, or E-mail: anna.cowan@anu.edu.au , about further meetings with the staff supervising those projects. If you have your own ideas about a project please consult Dr Cowan (every effort will be made to find a staff member willing to supervise the proposed project).

Further information on Neuroscience in all parts of the ANU can be found through the ANU library . Numerous web links are also scattered through the project outlines given below.

Prospective students should note that the Honours year usually begins in early February and finishes in late November (10 months). It is possible to start in July and finish the following May and some projects listed below demand this. A Graduate Diploma student is permitted up to 2 years full-time study but in Neuroscience we urge such students to join in with the Honours program and complete studies in 10-12 months, if the project permits.

Both Honours and Graduate Diploma students may study part-time and enrolment in either course does not need to be contiguous with completion of a Bachelors degree.

Dr John Bekkers, Cerebral Cortex Lab , JCSMR

How the Brain Decodes Odors The mammalian brain recognises and remembers odours in a specialised cortical region, the olfactory cortex, located just behind the nose in the ventral forebrain. The olfactory cortex has a remarkably simple anatomical structure, yet little is known about how it does its job. My laboratory is using patch clamp techniques to study the cellular physiology of the primary olfactory cortex of mice, with the eventual aim of understanding how the brain represents olfactory information. Projects are available that study synaptic transmission and excitability in acute slices of mouse olfactory cortex.

The role of different neuronal calcium sources in synaptic plasticity

The role of different neuronal calcium sources in synaptic plasticity

The term synaptic plasticity refers to the ability of neuronal connections to change their properties in response to particular types of input. This plasticity is important because it allows the brain to adapt to, and learn from, the external environment. One example of synaptic plasticity that is of particular interest is long-term potentiation (LTP) , which is widely believed to underlie learning and memory in the brain. LTP is a persistent enhancement of the strength, or efficacy, of a synapse in response to specific patterns of neuronal activity. This change is measured in the laboratory as a change in the size of the excitatory postsynaptic potential (EPSP) evoked by stimulation of presynaptic axons.

Much has been learned about LTP over the past 30 years, including the crucial role of postsynaptic calcium in triggering the change. It is also known that different biochemical pathways are important for maintaining LTP over different periods of time. We have recently found that different calcium sources in different parts of the neuron are selectively involved in triggering LTP of different durations. We are currently investigating various aspects of the physiological signalling underlying these different forms of LTP in the rat hippocampus. We will be using a combination of extracellular field recordings, whole-cell patch-clamp, and 2-photon laser scanning microscopy.

Reference:

Raymond CR and Redman SJ (2006) Spatial segregation of neuronal calcium signals encodes different forms of LTP in rat hippocampus. Journal of Physiology 570(1): 97-111

Our group is interested in the basic mechanisms of synaptic transmission in the mammalian central nervous system, how it is modulated and the efficiency with which information is transferred from one cell to another. This information is important for understanding defining principles in the functional connectivity of neuronal networks, how network behaviour is modified by preceeding or concurrent activity, and how networks adapt to environmental influences. Our current research is focussed on synaptic transmission between neurones in the somatosensory cortex in acute rat brain slices.

We offer projects in the following areas:

• Role of intracellular calcium stores in evoked and spontaneous transmitter release.
• Electrophysiology and/or modelling of synaptic dynamics.
• Computer-assisted reconstruction of connected cells and modelling of synaptic transmission.
• Mathematical modelling of non-random processes in synaptic transmission.

Dendrites: The brain within the brain.

Reference: Hausser M, Spruston N, Stuart GJ. Diversity and dynamics of dendritic signaling. Science. 2000 290:739-44.

Mechanisms of Axonal Signalling.

Photoreceptor and bipolar cell responses in vivo measured from the human electroretinogram (ERG)

The electroretinogram (ERG), measured from the living eye in response to illumination, comprises the summed activity of several types of retinal cell.The photoreceptors respond first and then, after a delay, signals arise from bipolar cells, and then from other more proximal retinal neurons.

In the Visual Neuroscience Laboratory we study responses from retinal neurons with the ERG technique, using full-field ("e;ganzfeld"e;) stimuli to stimulate the entire retina uniformly. Projects are offered in the following areas:

• Responses of cone photoreceptors to the cessation of a light stimulus.
• Responses of rod bipolar cells to very dim illumination.

The Blood Vessel Lab is interested in the formation and function of synapses between autonomic nerves and their target tissues. One of the more important of these targets is the cardiovascular system. Efficient coupling between smooth muscle cells of the walls of blood vessels seems crucial to the production of coordinated contractions following either receptor activation or in the case of spontaneous rhythmic contractions. Current studies are focused on mechanisms of arteriolar contractility with special emphasis on the role and regulation of cell to cell coupling through structures called gap junctions which in turn contain molecules called connexins. Evidence suggests that upregulation of connexin molecules plays an important role in cardiovascular disease, such as hypertension. Our current research aims to determine the precise role of connexins in nerve-mediated and spontaneous contractions, using intracellular recording techniques, single cell dye injection and calcium imaging. Dye coupling and calcium movements will also be measured after activation of neurotransmitter receptors and their linked intracellular pathways. Involvement of specific pathways can be tested using drugs which can interfere with or mimic the molecules mediating these pathways. It is hoped to extend these studies to blood vessels of mice in which connexin expression has been upregulated.

Hirschsprung's disease (HSCR) is a congenital malformation characterized by the absence of enteric ganglia (aganglionosis) and is associated with a variety of neurological disorders. HSCR in human, rat and mouse is polygenic, and the endothelin receptor B (ETRB) gene mutation is involved. One of our main scientific goals is to understand the cellular, molecular and functional abnormalities in the brains of HSCR patients, using a rat model of HSCR caused by an ETRB mutation (spotting lethal rat, sl rat). Our initial studies showed that substantially fewer proliferating cells but more apoptotic cells in many brain regions in sl rat, compared with normal littermates. We also expect to reveal significant changes in the biochemistry of sl rat brains, including altered levels of cytoskeletal proteins and production of neurotrophic factors and endothelins. We are conducting a battery of molecular biological and morphological tests in fetal and postnatal sl rats. Because the endothelin system interacts with the GDNF signalling system commonly involved in HSCR, our findings in the sl rat will contribute to the understanding of HSCR etiology in human. New understanding of the changes in the brains of HSCR patients will allow investigation of functional defects in the CNS.

Our group is interested in the basic mechanisms of synaptic transmission in the mammalian central nervous system. Our current research is focussed on synaptic transmission between neurones in the auditory system, as this system offers unique technical advantages for the study of fundamental synaptic mechanisms. We offer projects in two main areas of research: neurophysiology and neuroanatomy.

Electrophysiological measurements of synaptic currents

The mechanisms of synaptic transmission will be studied in thin slices of living brain tissue. Neurones will be visualized in thin brain slices using special infra-red video microscopy, and recordings of synaptic currents made using patch-electrodes. Calcium is the major trigger for neurotransmitter release and experiments will be carried out to determine the role and modulation of different calcium channels in transmitter release at auditory synapses.

Neuroanatomical studies of synaptic structure

The clustering of neurotransmitter receptors in the postsynaptic membrane is an important determinant of synaptic strength. The location and clustering of these receptors will be studied using intracellular fluorescence labelling of individual neurones in conjunction with immunohistochemical localization of specific receptors. The clustering of receptors will be mapped over the surface of the neurones using confocal microscopy.

Molecular mechanisms of ion channel function

The ligand-gated ion channels combine the functionalities of a receptor and an ion channel in a single protein, and mediate fast synaptic signalling in the central nervous system. I endeavour to understand the function of these multi-subunit protein complexes from the perspective of a protein chemist, in both native and model systems. The functional studies are focused on GABA A receptors with an emphasis on drug modulation (benzodiazepines, anaesthetics, barbiturates) and the relationship between drug action and the organised expression of GABA A receptors. Possible projects are outlined briefly below.

Functional consequences of clustering GABA A receptor and the physical interactions underlying clustering.

The GABAA receptor is the major inhibitory ligand-gated ion channel in the central nervous system. Receptors are found clustered at synapses and may be either dispersed or clustered at extrasynaptic locations. These three pools of GABA A receptors have important functional differences and their relative expression levels are critical for not only neuronal inhibition, but also basic functions such as learning and memory, motor and cognitive functions as well as clinical areas such as epilepsy, sleep disorders, anxiety and drugs of dependence. We have shown that recombinant receptors clustered by the GABA A receptor associated protein (GABARAP) behave differently when clustered. The conductance of the ion channel increases and drugs are more efficacious.

a) Identification of GABA A subunit interaction partners. : Clustering of GABA A receptors involves a physical interaction between receptors. To identify the specific subunits involved in receptor interactions and their interacting sequences, a recombinant expression system will be used to express and purify fragments of GABA A subunits. Combinations of fragments will then be tested for specific interactions using a modified Western blotting technique.

b) Single channel properties of extrasynaptic GABA A channels. Using the patch clamp technique the electrophysiological consequences of clustering and declustering will be examined, with particular attention to how drug effects are altered.


Selected Publications:

• Luu T, Gage PW, Tierney ML. 2006. GABA increases both the conductance and mean open time of recombinant GABA A channels co-expressed with GABARAP. J Biol Chem accepted .
• Everitt AB, Tien T, Cromer B, Tierney ML, Birnir B, Olsen RW, Gage PW. 2004. Conductance of recombinant GABA A receptors is increased in cells co-expressing GABARAP. J Biol Chem 279: 21701-06.
• Eghbali M, Curmi JP, Birnir B, Gage PW. 1997. Hippocampal GABA A channel conductance increased by diazepam. Nature 388: 71-75.

Dr Rosemary Martin , Division of Biochemistry & Molecular Biology, The Faculties

Recycling of glutamate and GABA in the brain

Glutamate is the most abundant excitatory neurotransmitter in the brain. It is involved in fast neurotransmission underlying thinking, memory, movement, processing of sensual information etc. After its release into the synaptic cleft its action is terminated by uptake of glutamate into neighbouring astrocytes. Inside astrocytes, glutamate is converted into glutamine, which is released from astrocytes and subsequently used by neurons to synthesize glutamate. My group is interested in the function and regulation of transporters mediating the transfer of glutamine between astrocytes and neurons. Alterations in the activity of these transporters might influence neuronal activity. A similar recycling process is also observed in the case of the major inhibitory neurotransmitter GABA. We use primary cultures of brain astrocytes and neurons to analyze the mechanism of metabolite release and the regulation of these processes. To characterize the transporters on a molecular level we express them in Xenopus laevis oocytes and analyze their function by biochemical techniques and flux studies. Available honours project:

Identification and characterisation of novel members of the neurotransmitter transporter family.
The aim of the study would be to identify the major pathways which mediate glutamine uptake into neurons. We have recently identified a new member of the neurotransmitter transporter family, which now allows us to study the function of previously uncharacterised members of this family. We will clone the transporters from mouse brain, express them in oocytes and characterise their function in neuronal or astroglial cell cultures.

References:

• Broer, A., Deitmer, J. W., and Broer, S. (2004). Astroglial glutamine transport by system N is upregulated by glutamate. Glia 48, 298-310.
• Kowalczuk, S., Broer, A., Munzinger, M., Tietze, N., Klingel, K., and Broer, S. (2005). Molecular cloning of the mouse IMINO system: an Na+- and Cl--dependent proline transporter. Biochem J 386, 417-422
• Seow, H. F., Broer, S., Broer, A., Bailey, C. G., Potter, S. J., Cavanaugh, J. A., and Rasko, J. E. (2004). Hartnup disorder is caused by mutations in the gene encoding the neutral amino acid transporter SLC6A19. Nat Genet 36, 1003-1007.
• Broer, S.,Brookes, N., 2001. Transfer of glutamine between astrocytes and neurons. J. Neurochem 77, 705-19.

Professor Jonathan Stone and Dr Krisztina Valter, CNS Stability and Degeneration Group, RSBS

• electrophysiology, ERG recordings and data analysis
• histological techniques, high level microscopy on confocal and/or deconvolution microscope
• immunohistological techniques
• molecular techniques incl genechip/gene array, real-time PCR

Projects currently active:

• Effects of environmental factors on the rodent retina
• Protective mechanisms in the rodent retina
• Molecular mechanisms of retinal degeneration
• Roles of mitochondria in retinal degenerations

Further opportunities in new and future projects:

• The role of neuroglobins in the retina - a structural and molecular approach
• Crystallins in the retina
• Molecular genetics of oxygen vulnerability

Reference: Stone, J., Maslim, J., Valter-Kocsi, K., Mervin, K., Bowers, F., Chu, Y., Barnett, N., Fisher, S.K., Lewis, G., Bisti, S., Gargini, C., Cervetto, L., Merin, S. and Pe'er, J. Mechanisms of photoreceptor death and survival in mammalian retina. Progress in Retinal and Eye Research 1999; 18:689-735.

Patterning in the Outer Retina of Chicks and Humans.

In the developing chick retina, there are distinct dorsal and ventral gene expression patterns which do not overlap along the horizontal meridian. Rather, there is a middle ground where neither dorsal nor ventral genes are expressed, in which territory a rod-free (pure cone) region, resembling the incipient fovea of the primate, later forms. Using a targeted gene approach, and in collaboration with Dr Keely Bumsted-O'Brian at the University of Auckland, we are carrying out a comparative analyses of chick with human and macaque foetal retinas to attempt to identify genes which specify the rod-free, cone-rich region of primate retina. The project involves Laser Capture Microdissection, PCR, confocal microscopy and image analysis.

The worker honeybee carries a tiny brain. It occupies a volume of about a cubic millimetre, weighs about one milligram and contains about a million neurones. Nevertheless, this creature, by virtue of its lifestyle, is a spectacularly suitable organism for studying principles of pattern recognition and learning in a general sense. Over the past decade, work on the honeybee in our laboratory is beginning to suggest that insects may not be the simple, reflexive creatures that they were once believed to be. Bees display perceptual and "cognitive" capacities that are surprisingly rich, complex and flexible. Our research focuses on the following issues:

Study of memory organisation

We are using the delayed match-to-sample (DMTS) paradigm to study various aspects of memory formation. In the DMTS task, a bee has to learn to match an "indicator" stimulus that it encounters at the entrance to a maze with one of two other test stimuli that it subsequently encounters in a decision chamber. In such a task, the bee has to remember the indicator at the entrance and determine which of the test stimuli corresponds to it. In the DMTS task, two types of memories are involved. First of all the bee has to learn, remember and recall the rules of the task. This is an aspect of long-term memory (or so-called "reference" memory). On the other hand, whilst executing the actual task the bee has to temporarily remember the indicator stimulus in order to carry out the matching task. This involves short-term memory (or so-called "working" memory). We intend to investigate the properties of reference memory and working memory using behavioural and pharmacological approaches.

Categorization of visual stimuli

Recent work in our laboratory has revealed that honeybees are capable of conceptually grouping visual patterns into various categories such as stripes, rings and checkerboards. They can also group natural scenes into various categories such as flowers, plants and landscapes. The next steps in this research would be to investigate what cues honeybees use to make these categorizations, and to determine to what extent the ability to categorize is innate or acquired through experience.

Molecular basis of experience-dependent brain plasticity in the honeybee, genes and their products, functional neurogenomics. Our broadly defined goal is to understand how gene function translates to behaviour. Using a simple, easily manageable model organism, the Western honeybee ( Apis mellifera ), we are creating databases of gene expression patterns in the brain that allow us to unravel the intricacies of genetic networks controlling the behavioural development of this species in the context of learning and sociality. To achieve our goals we are using state-of-the-art molecular technologies combined with pharmacological and behavioural approaches.

Recent publications

Si, A., Zhang, S. W. and Maleszka, R. (2005) Effects of caffeine on olfactory and visual learning in the honey bee ( Apis mellifera ). Pharmacol. Biochem. Behav. 82, 664-672.

Kucharski, R. and Maleszka, R. (2005) Microarray and rtPCR analyses of gene expression in the honey bee brain following caffeine treatment. J. Mol. Neurosci. 27:269-276

Jones JC, Helliwell P, Beekman M, Maleszka R, Oldroyd BP. (2005)The effects of rearing temperature on developmental stability and learning and memory in the honey bee, Apis mellifera . J Comp Physiol A. 28:1-9.

You can do an Honours project in one of three research areas in my laboratory. You can study visual processing in humans, cats or insects. All the projects are working towards understanding how moving scenes are processed by the nervous system.

Human visual psychophysics

In these experiments subjects are presented with a series of visual stimuli that probe the mechanisms used by humans to extract motion from the visual image during locomotion, i.e. during walking, driving and sport. Subjects are instructed to respond based on their perception of what the stimulus is doing. Computer literate neuroscience and/or psychology students are qualified for this type of project.

Cat vision

We record from single neurons in the visual cortex of anaesthetised cats. Although the cat is unconscious, its sensory system is still fully functional (as illustrated by the fact that an alarm clock or bright light will wake you from deep sleep). We record from areas of the brain specialised in detecting visual motion. The sleeping cat is presented with visual stimuli and we record the responses of individual cells. In this way, we can learn about the specific cellular mechanisms underlying visual processing and perception. These experiments are demanding but students aiming for a career in neuroscience are strongly encouraged to apply.

Insect vision

Despite their small brains, flying insects have highly sophisticated visual motion processing systems. The department is trying to mimic the intricate processing that occurs in insect brains to build autonomous flying vehicles. As the engineering component of this project develops, we need to learn more about the functioning of the insect brain. Experiments involve intracellular recording from single visual neurons in the brains of honeybees and subsequent reconstruction of the neurons using 3-dimensional visualisation programs. The stimulus environment is similar to that used for cats but recording from insects is less demanding. Anybody with a neuroscience interest is encouraged to apply.

The main research interests of my colleagues and I are in the area of dynamic, adaptive and nonlinear vision. Techniques in the lab include eye movement monitoring, psychophysical, behavioural, and evoked potential (EP) methods. An area of interest is what visual illusions can tell us about visual processing. A list of possible Ph.D. or Honours projects follow although projects proposed by students that fall within our interests and techniques are encouraged.

Evoked Potentials - New methods allow EP responses to many concurrently presented stimuli to be measured. Applied to glaucoma and multiple sclerosis.

Illusory brightness - Illusory brightness, as seen in the Craik-O'Brien-Cornsweet (COC) effect, can be investigated in humans and bees.

Apparent Fineness - Certain patterns are seen to have a scale that is illusory. Our initial work has shown that cortical processing accounts for some of the effect.

Spatial Frequency Doubling - We have used FD in new tests for glaucoma that are being sold internationally. We would examine how and why we see this illusion.

Texture Discrimination - Iso-trigon textures is of particular interest here. Both Human and Bee studies have been conducted.

Second Order Motion - This project looks at a case where one of these possible mechanisms appears to break down.

Eye Movements - The study uses eye movements to investigate adaptive effects under relatively natural conditions. Application to glaucoma is also possible.

We have described a circuit in the retina consisting of the photoreceptors, dopaminergic amacrine cells and amacrine cells which are immunoreactive to enkephalins, somatostatin and neurotensin (the ENSLI amacrine cells). This circuit appears to function as a switch, flipping from a dark to a light state at quite low light intensities. It is important in relation to control of circadian rhythms and of retinal sensitivity at different light levels through its regulation of the rate of release of dopamine, melatonin and retinal peptides.

This circuit also appears to play a role in relation to the control of eye growth, primarily through the regulation of dopamine release. This area of research has become important because of the emergence of an epidemic of myopia in urban East Asia, where over 90% of school leavers are currently myopia, and around 20% with such severe myopia that they are at significantly increased risk of low vision and blindness. This epidemic appears to be slowly spreading to other parts of the world. Our laboratory-based work in Canberra deals with the molecular and cellular basis of eye growth control in animal models of myopia. In parallel, we carry out epidemiological work in Sydney and Singapore in collaboration with the School of Applied Vision Sciences and the Department of Ophthalmology at Sydney University, and the Singapore Eye Research Institute.

Recent laboratory work has shown that the interactions between stimuli that promote and inhibit eye growth and myopia are highly non-linear. Specifically, short periods of growth inhibitory signals can neutralise prolonged exposure to stimuli that promote eye growth. Based on this discovery, we have obtained promising results in a series of clinical interventions aimed at preventing the worsening of myopia with plus lenses. This approach is now the subject of a randomised clinical trial in Singapore, with a further trial planned in Guangzhou. The role of dopamine in the suppression of eye growth with plus lenses is now being studied in the laboratory.

At the same time, our epidemiological work has shown that greater amounts of time spent outdoors protect from the development of myopia. We have reproduced this effect in animal models. Our hypothesis is that the high light intensities typical of day-light hours outside promote the release of dopamine, which is known to act, in certain circumstances, as a growth inhibitor.

Reverse-engineering the dragonfly ocellar visual system: creating a blueprint for the design of control systems in flying robots

Most adult insects carry two visual systems, namely a pair of compound eyes and a triplet of simple eyes, the dorsal ocelli. Knowing that one of the functions of the ocelli is the maintenance of equilibrium during flight, the biorobotics group at RSBS has recently implemented a biomimetic version of the underlying principles and have designed a control system for robotic miniature aircraft, with superior performance. This engineering effort has, in turn, inspired a new round of biological research, with unexpected results. The ocellar system of dragonflies exhibits features that were previously unknown, such as image formation by focused optics. The resulting new project comprises many aspects and methods, suitable as distinct topics for honours projects.

• Development of an understanding of image processing in the dragonfly ocellar system.
• Description of the detailed anatomical structure of the dragonfly ocellar system.
• Description of the anatomy and physiology of the output neurons that convey the visual information from the ocelli to the brain and motor control systems of the animal.
• Understanding of the biophysical mechanisms (via intracellular recording) that allow the ocellar system to extract complex information such as object detection from the image of the world produced by the ocellar lenses.
• Characterization of the ocellar optical properties, by refractometry of the lenses and ray tracing, together with direct observation of the images formed by excised ocelli.
• Electrophysiological recordings from single receptor neurons, in order to determine receptor neuron visual fields and acceptance angles and to determine the transfer characteristics in the intensity, spectral and time domains.
• Electrophysiological recordings from second order cells and establishment of an inventory of structurally and functionally identified second order neurons, the determination of their functional properties being the main component of the project.
• Application of computer-generated visual stimuli that are partially controlled by the output of the neuron under investigation, akin to virtual-reality systems.
• Provision of information on central projections and putative interactions between ocelli, compound eyes and other sensory modalities.
• Behavioral experiments on tethered dragonflies in a wind tunnel, in order to determine whether moving visual stimuli applied to the ocelli evoke steering responses.

The biological results will be applied to the further development of concepts for novel attitude control systems capable of being implemented in ultra-light hardware for application to micro-unmanned aerial vehicles.

Mammalian Colour Vision

With the exception of some primates, most mammals are dichromats. This means they have only two spectral cone classes as opposed to three for trichromats (eg. humans). Recent research, however, has indicated that at least some marsupials are also trichromatic. It is as yet unclear what the exact nature of the third marsupial cone class is. We have recently started a program to explore colour vision in different marsupials in more detail, using behavioural, anatomical (immunocytochemistry) and physiological techniques to characterise their colour vision. There is a range of potential honours or PhD projects available in this area using one or more of the techniques described. I am also open for project proposals in the area of colour vision or one that is related to the fiddler crab work (see below).

Drs Jochen Zeil & Jan Hemmi, Visual Ecology and Comparative Vision, Visual Sciences, RSBS

To fully appreciate and understand the properties of neurons and of sensory systems, there is a need to analyse the natural conditions in which animals process information. Neural systems, like all other biological systems, have evolved in a specific context, defined by the tasks animals have to solve and the environment in which they live. We are particularly interested in understanding how visual systems are shaped by these "real life conditions" and currently work on the following projects:

Visual ecology of fiddler crabs

We attempt to establish an inventory of visual tasks in fiddler crabs. The crabs' eyes are exquisitely tuned to the visual geometry of the flat world these animals inhabit. We analyse behaviour to identify the visual cues used by the crabs in predator avoidance and social interactions and employ a suite of fancy imaging devices to analyse visual signals and natural scenes from crab perspective. Interesting challenges are to understand (a) colour vision in fiddler crabs, (b) the signalling function of their variable body colours, (c) the choreography of their waving displays and (d) the image motion signals these displays present to the brain of a crab observer.

View-based homing in insects

Homing insects are thought to use snapshots of the goal environment when navigating back to their nest or a feeding site. Many fundamental aspects of "view-based" navigation are not understood. We use a panoramic imaging device on a robotic gantry (which we can wheel around the ANU) to reconstruct what flying insects see and to study the limits of view-based navigation outdoors. Projects include (a) the reconstruction of natural optic flow, (b) the effects of environmental motion and of variable illumination on view-based homing and (c) testing different homing algorithms under natural conditions.