Photonics and Life Cell Imaging
Program Committee
Marloes Groot (program leader)
Huibert Mansvelder (program leader)
Johannes de Boer
George Kraal
Erwin Peterman
Ruud Toonen
Gijs Wuite
Davide Iannuzzi
Rationale
Photonics & life cell imaging is a technology development research program in which expertise of the collaborating groups at the LCVU, AMOLF and CNCR is united to develop new imaging paradigms. We aim to develop imaging techniques that can be applied to yield fundamental knowledge on in vitro systems and that in a second stage can be applied to in vivo and clinical studies. In particular this involves developments with a focus on high spatial resolution, deep tissue penetration, video imaging rates and intrinsic markers. Success of this project demands an intensive collaboration between physicists and biologists. This project has close connections with the new developments in the LaserCentre of the VU, which, supported by a NWO Groot investment grant, will expand its research in the direction biomedical photonics.
Background
A growing body of literature suggests that cognitive dysfunction in brain diseases such as Alzheimer’s (AD), Parkinson’s (PD) diseases and X-linked mental retardation disorders are associated with loss of synaptic plasticity and connectivity in neuronal networks. These neuropsychiatric diseases are characterized by morphological changes in dendrites and spines, and the progressive dysfunction of synaptic contacts involves connections between principal neurons (pyramidal cells) and various other types of neurons. Thus, changes in synaptic function and neuronal connectivity are most likely responsible for the decline in cognitive abilities in these brain disorders. A major future challenge will be to be able to detect these changes at an early enough stage to be able to halt and ultimately revert these pathological processes. The ability to detect biological changes at the (sub-) cellular level in vivo plays a key role for future progress in molecular neuroscience. This leads to a demand for new technologies and biomarkers, which will enable the identification and manipulation of neuropathological processes in a pre-clinical stage. Visualizing the flow of activity through identifiable brain circuits with (sub-) cellular resolution during behavior would be one of the most important accomplishments in the modern neuroscience era.
Executive summary
We will develop integrated non-linear optical imaging systems consisting of in vitro imaging platform and in vivo, whole animal, imaging platforms that make optimal use of shared versatile laser systems. Dedicated researchers will develop the setups and perform in vitro experiments aimed at photo-detection of the neurotransmitters involved in neurological disorders such as depression, Alzheimer’s (AD) and Parkinson’s (PD) disease: serotonin, dopamine and acetylcholine. Novel 2- and 3-photon excitation schemes will be explored that optimize detection and minimize phototoxicity. An addition we will identify the optimal conditions for deep-tissue imaging of endogenous fluorophores and tissue/cell morphology using pulse shaping, second- and third harmonic generation as well as Spectral Domain Optical Coherence Tomography (SDOCT).
The in vitro imaging will be complemented and extended towards ongoing research at the CNCR using transgenic models available at this center. In doing so we will translate optimal biophysical detection schemes obtained on the in vitro platform to the in vivo situation; further we will apply SDOCT in cortical networks to detect early morphological markers of degenerative brain disorders, such as Alzheimer’s and Parkinson’s disease. In addition, we intend to measure dendritic calcium dynamics in developing neurons in Fragile X syndrome, detect molecular mechanisms of synaptic vesicle and large-dense core vesicle exocytosis, and investigate axon guidance and target finding in secretion-deficient transgenic mouse models. In parallel to this we will setup a second in vivo imaging platform to study among others issues of inflammation and autoimmunity in relation to Multiple Sclerosis.
Future Perspectives
Advancement in neuroscience research requires the development of techniques that enable in vivo visualization of individual neurons, neuronal networks, and synaptic contacts, with high spatial and temporal resolution and penetration depth, while these circuits are processing information. The development of new optical in vivo imaging modalities that have sub-cellular resolution will allow identification of novel biomarkers for early detection of brain disease. New optical tools can, in addition to identification of new biomarkers, also be developed to perturb and interfere with the progression of disease at very early (pre-clinical) stages. We aim to develop a state of the art microscope that combines the newest developments in the field to further develop these techniques to advance neuroscience research performed at the VU.
