Dual-line femtosecond laser for use on the multiphoton microscope

• Subject Area: Neurosciences ; Basic Research in Biology and Medicine
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 567866377

A fully automated dual-line femtosecond laser with a fully dispersion-compensated tuning range (adjustment range of 680 nm-1300 nm and second fixed line at 1045 nm) of the current generation (>1.0 W at 700 and 1300 nm and >3.5 W at 1045 nm) is requested. It is intended to replace the existing laser of the same type on the multiphoton microscope, which no longer provides the required power due to its operating lifetime. The new system will enable label-free in vivo imaging using autofluorescence and backward Second Harmonic Generation (SHG) in the ongoing projects and will also enable the analysis of forward SHG and Third Harmonic Generation (THG) signals. For this purpose, the system is to be equipped with transmitted NDD detectors (for forward SHG) and a true resolution water immersion objective (NA 1.05) with a high transmission rate for wavelengths >1100 nm and new sensitive reflected NDD detectors (for THG). The existing laser is to be integrated into the modular platform system for time-resolved confocal fluorescence microscopy. This allows the same sample to be analyzed multimodally with high precision not only by means of fluorescence lifetime and anisotropy, but also with regard to SHG. The focus of the work on the multiphoton microscope and the setup of time-resolved confocal fluorescence microscopy is on the native analysis of murine and human organ, tissue and cell samples as well as on the whole animal model. In the cellular model, the compartmentalization of the glucose sensor enzyme glucokinase in hepatocytes and the mitochondrial life cycle and metabolism in pancreatic beta cells will be investigated. New aspects of diabetic neuropathy in the skin and eye in mouse and rat models will be elaborated. In addition, pathologies of the cornea and lens of the eye will be analyzed in human surgical explants with a focus on changes in the cell structure and architecture of the extracellular matrix (collagen, elastin and other connective tissue). Detailed studies on collagen remodeling will expand our understanding of the underlying pathomechanisms and identify new therapeutic options. Muscle changes during embryogenesis and the ageing process in the mouse model will be visualized and assessed both qualitatively and quantitatively. During embryogenesis, the composition of the murine abdominal wall in the developmental process will be described with a focus on the closure of the midline in order to better understand pathologies with the formation of a congenital hernia due to insufficient regression of the physiological umbilical hernia. The characterization of fast and slow muscle fibers (extensor digitorum longus and soleus muscles) at the level of the individual muscle fiber as well as the entire muscle (including connective tissue) will enable the comprehensive assessment of physiological and biochemical parameters of aging processes.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Dual-line Femtosekundenlaser zur Nutzung am Multiphotonenmikroskop
• Instrumentation Group: 5060 Mikroskopbeleuchtung
• Applicant Institution: Universität Rostock
• Leader: Professorin Dr. Simone Baltrusch