This Satellite Symposium brings together many of the leaders in the field of imaging to present recent results and developments in imaging. The symposium will have speakers working on cellular imaging (confocal and multiphoton imaging), whole field imaging (MRI and PET) as well as optogenetic techniques.

The ANS 2012 Satellite Symposium on Imaging will take place at the Queensland Brain Institute on Saturday 28 and Sunday 29 January 2012. There is no charge to attend the symposium, but registration is required for catering purposes. To register contact  Sue Campbell  email: s.campbell4@uq.edu.au  phone 3346 3328.
 

 

 

 

Program for ANS 2012 Satellite Symposium on Imaging

Queensland Brain Institute

Saturday 28 and Sunday 29 January 2012

 

Time

Speaker

 

Saturday 28 January 2012

  1.00 - 1.10pm

Welcome

  1.10 - 1.30pm

Dr John Power, Queensland Brain Institute, UQ – Calcium store release in amygdala neurons.

The majority of connections between excitatory neurons are made on small, specialized compartments call spines.  These structures are connected to the neuron by a thin neck that limits diffusion from spine head, enabling signalling molecules, such as calcium, and the changes they trigger, to be restricted to individual synaptic connections between neurons.  At nearly all synapses in the brain the induction of synaptic plasticity requires a rise in spine calcium, which is thought to occur via calcium influx through NMDA glutamate receptors.  In the basolateral amygdala learning and synaptic plasticity also require activation of metabotropic receptors.  Using two-photon fluorescence imaging we have shown that activation of these G-protein coupled receptors raises spine calcium through release of calcium from IP3-sensitive intracellular calcium stores.  This IP3-sensitive spinal calcium response results from calcium stores release in the spine head itself and from the invasion of propagating dendritic calcium waves.  

 

 

  1.30 - 1.50pm

A/Prof Peter Thorn, School of Biomedial Sciences, UQ – Rea-time imaging exocytosis in intact islets of Langerhans.

Real –time imaging exocytosis in intact Islets of Langerhans.

 

Glucose homeostasis is maintained by the secretion of insulin from the pancreatic beta cells of the islets of Langerhans. Type 2 diabetes is known to result, in part, from a defect in insulin secretion with evidence that it is the final stages of exocytosis that are compromised. Our long-term aim is to understand the control of secretion in normal and diseased cells. We have set out to determine the kinetics of exocytic fusion in intact islets and here I will present evidence that transient granule fusion is important in the beta cells.

  1.50 - 2.10pm

Pankaj Sah – QBI – Intrinsic circuitry of the amygdala

The amygdaloid complex is temporal lobe structure that plays a key role in fear learning and expression.  It is divided into a large number of nuclei that have extensive intrinsic as well as inter nuclear connections.  Most, but not all sensory information enters the amygdaloid complex via the basolateral amygdala (BLA) where it is initially processed.  This information is then transmitted to the central nucleus, the outputs of which mediate the physiological responses to learnt fear.  The intrinsic circuitry of this interesting region has till now been studied using a combination of tract tracing and in vitro electrophysiological recordings.   However, tract tracing largely provides anatomical information showing the connections between regions and does not provide information on which cells are being innervated. In vitro slices recordings will provide this information, but because the amygdala does not have a clear anatomical organisation, stimulation of specific inputs in slices are not possible. To get around these problems, we have begun to use optical stimulation using channelrhodopsin and in vitro slice recordings to understand the intrinsic amygdala circuitry.  I will describe our preliminary data investigating the local circuitry of the basolateral showing the responses to cortical and thalamic inputs to neurons in the amygdala.

 

  2.10 - 2.30pm

Graham Galloway – Ultra high field human MRI imaging.
MRI has become the imaging modality of choice for many neurological clinical assessments. The reason is that it offers excellent resolution and a wide range of endogenous contrast, which can be used to identify anatomical and pathological features. As it does not employ ionizing radiation, it is considered non-invasive, making it far preferable for repeated examinations to follow the course of a disease and the effect of therapy.

The push towards better resolution and higher speed has driven the desire for higher magnetic field. This has meant stretching the engineering to the limits, which has significant implications for system maintenance and quality assurance. The engineers and physicists responsible for these systems need to have an understanding of the underlying principles and an appreciation of the sources of error, how they can be detected, and what actions need to be employed to minimize their effects.

This presentation will introduce some of the basics of MR physics, present some of the new applications, and describe some of the potential pitfalls that need to be addressed at the local level.

  2.30 - 2.50pm

Dr Ross Cunnington, Queensland Brain Institute, UQ –  High-resolution functional MRI of the basal ganglia and thalamus at 7 Tesla.
Motor regions in the midline of the brain, including the supplementary motor area (SMA) and cingulate motor areas, form re-entrant loops with specific nuclei of the basal ganglia and thalamus that are crucial for the planning and control of voluntary action. Most of what is known about basal-ganglia-cortical motor circuits comes from direct neuronal recordings in monkeys, as human brain imaging studies typically lack the spatial resolution to delineate activation in different nuclei of the basal ganglia and thalamus. In this study, use we ultra-high field MRI at 7.0 Tesla for high-resolution functional imaging of the motor circuits involved specifically in motor timing compared with sequencing of voluntary actions. For complex sequencing, a region of the SMA-proper was significantly more active, together with dorsal premotor and parietal cortical regions bilaterally. For complex timing, a region more superior and anterior in the pre-SMA was significantly more active, together with bilateral activation in the head and body of the caudate nucleus of the basal ganglia. High-resolution fMRI was able to clearly delineate activation within different parts of the basal ganglia and thalamus, and suggest that basal ganglia motor circuits are most involved in co-ordinating complex timing of voluntary actions.

  2.50 - 3.20pm

Afternoon Tea

  3.20 - 4.20pm

Bernd Pichler – Advances in MR/PET

“The combination of Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) merges functional, molecular und morphological information together. Integrated PET/MRI systems thus allow the temporal and spatial correlation of multiparametric imaging data. PET/MRI was pioneered in the realm of small animal imaging where functional and molecular information is desired along with high resolution and high soft tissue contrast morphology provided by the MRI. The development of multimodal PET/MR imaging took over 15 years of research, especially for new detector technology for PET. Just recently became a first fully integrated clinical whole body PET/MRI system commercially available. Also first commercial sequential or simultaneous small animal imaging PET/MR systems are on the horizon. Especially the fields of oncology and neurology will benefit from this new imaging system. While in oncology the tumor morphology will be supplemented by the molecular information providing the status of glucose metabolism or receptor expression, in neurology the combination of functional information such as blood flow, diffusion or the BOLD effect along with specific receptor expression, provided by PET, will be a major application. Hence we valuated and cross-validated functional MRI (fMRI), BOLD effect or arterial spin labelling with PET measurements assessing the glucose metabolism by F18-FDG or the perfusion by O15-water PET. The talk will provide an overview about the potential of PET/MRI in neurology.”

  4.20 - 4.40pm

Steve Meikle – Advances in animal PET neuroimaging

“Positron emission tomography (PET) is now a well developed tool for preclinical research and drug development. Current state of the art animal PET systems are capable of achieving spatial resolution approaching 1mm and sensitivity approaching 10%. With these parameters, they are suitable for imaging the rodent brain in order to study metabolic pathways and receptor-ligand systems in living subjects. However, there are also some limitations of the technology. For example, 1mm spatial resolution is in many cases inadequate for the mouse brain and the quantitative accuracy of rat brain measurements is limited by the partial volume effect. Furthermore, PET requires the animal to be anaesthetised which interferes with important aspects of brain function and precludes a potentially diverse range of experimental paradigms on conscious animals. In this paper, recent advances addressing these challenges will be explored and discussed.”

  4.40 - 5.00pm

Leigh Johnston – Diffusion MRI – Imaging axonal size

“Diffusion weighted MRI can be used to probe structure in the brain at the micron-level scale, by varying sequence parameters such as diffusion time, gradient duration and gradient strength, that typically remain constant in a traditional dMRI scan.  This talk will outline models of the biophysical processes that give rise to the measured q-space data, and will present techniques for the inference of biologically meaningful parameters of the underlying system.  Of particular interest is axon diameter density, a key indicator of white matter integrity in normal and diseased states.”

  5.00 - 5.20pm

David Reutens – High field animal MR imaging

“Ultra high field MRI provides the ability to image the animal brain at microscopic resolution and with novel mechanisms of contrast. This talk will discuss:

1. the creation of anatomical models and probabilistic atlases of brain and spinal cord using ultra high field MRI and mouse and zebrafish.

2. the use of Volumetry and diffusion imaging to phenotype experimental models, providing complementary information to histology 3. Applications of functional imaging.”

  6.30pm

Speakers dinner at Hillstone, St Lucia Golf Course

 

 

 

Sunday 29 January 2012

  9.00 - 10.00am

Dr Feng Zhang, Broad Institute of MIT and Harvard, McGovern Institute for Brain Research, Massachussetts Institute of Technology, Cambridge, MA, USA- Optogenetics: Development and Applications

The integration of genetic, behavioral, and engineering techniques has enabled us to chart the heterogeneous cellular and circuit organization of the brain with unprecedented resolution. Yet, the emerging brain atlas is both illuminating and perplexing in its complexity. How do brain circuit elements interoperate and give rise to the panoply of behavioral and cognitive functions?

Recent developments in optogenetic technologies (channelrhodopsins and halorhodopsins) are beginning to give researchers the ability to reverse engineer intact neural circuits, by directly probing the necessity and sufficiency of cellular and topological circuit characteristics with high-speed and cell type-specific perturbations, using light to directly activate or inhibit specific neurons. Our latest developments have focused on three directions: 1) expanding the repertoire of genetically-encoded neuromodulators for controlling a variety of cellular functions, 2) developing better cell-type and circuit-specific gene targeting and genome engineering systems, and 3) integrating optogenetics with a variety of circuit-level and behavioral readout methods. The emerging optogenetic platform enables deconstruction of  previously inaccessible brain circuits, and will improve our understanding of the causal relationship between circuit activities and neuropsychiatric diseases.

  10.00 - 10.20

Greg Stuart, ANU – Electrical properties of dendritic spines.

  10.20 - 10.40

Morning Tea

  10.40 - 11.00

Fernando Calamante  - Diffusion MRI track density Imaging

“Despite the immense role to neurosciences, MRI suffers from an intrinsic limitation: spatial resolution, signal-to-noise ratio (SNR), and acquisition-time are strongly coupled; this makes it impossible to improve any of them without compromising the others. This presentation will describe the recently developed super-resolution track-density imaging (TDI) technique [1], which generates higher-resolution images with exquisite contrast by incorporating the long-range information from whole-brain fibre-tracking. TDI can produce human brain MRI images with higher resolution than previously possible in vivo. Importantly, this can be achieved not at the expense of SNR or by an associated increased acquisition-time. The super-resolution properties of the TDI methodology have been recently validated using in vivo human 7 Tesla MRI data and simulated data from a realistic in silico phantom [2]). Furthermore, the anatomical information content of the TDI images was assessed using ex vivo mouse 16.4 Tesla MRI data and compared with histological staining in the same brains [3]. Finally, a generalised framework to extend the TDI principles to generate super-resolution track-weighted imaging (TWI) will be described [4].”

  11.00 - 11.20

Victor Villemagne – Advances in human PET imaging

“With the advent of new therapeutic strategies aimed at reducing b-amyloid (Ab) and tau burden in the brain to potentially prevent or delay functional and irreversible cognitive loss, there is increased interest in developing agents that allow assessment of Ab and tau burden in vivo.  Molecular neuroimaging techniques such as PET, in conjunction with related biomarkers in plasma and CSF, are proving valuable in the early and differential diagnosis of Alzheimer’s disease (AD). ”

  11.20 - 11.40

Andrew Janke – Neuroinformatics and multimodal imaging.

“The more data we acquire with our latest and greatest imaging toys inevitably leads to information overload. 10TB multi-modal datasets per subject also present their own unique challenges. It is the role of the neuroinformatics community to make sense of this data and extract what would be considered pertinent for the particular research question at hand despite this often being sourced from multiple imaging sources. These larger datasets of populations also allow us to make inferences about the distribution of variance in our own study populations as compared to the whole. This presentation will give an overview of current techniques used to make sense of such massive multi-modal datasets.”

 

  11.40 - 1.00

 

Lunch and Seminar ends