Nonlinear light microscopy has brought about a significant change in how we observe and comprehend complex biological processes. However, it is crucial to recognize that intense light can lead to damage in living organisms. The precise mechanism behind this irreversible perturbation of cellular processes due to intense light exposure is not fully understood.
Researchers at the Max Planck Institute for the Science of Light and Max-Planck-Zentrum have collaborated to investigate the conditions under which intense pulsed lasers can be used in vivo without causing harm to the organism. By utilizing zebrafish as a model, the international team based in Erlangen has delved into the mechanisms of photodamage in deep tissue at a cellular level triggered by femtosecond excitation pulses.
The study, published in Communications Physics, highlights that damage to the central nervous system of zebrafish occurs abruptly when irradiated by femtosecond pulses at 1030 nm. This damage occurs at extreme peak intensities required for low-density plasma formation. However, it was discovered that as long as the peak intensity remains below the low-plasma density threshold, there can be a noninvasive increase in imaging dwell time and photon flux during irradiation at 1030 nm. These findings are crucial for nonlinear label-free microscopy techniques.
The results of this research significantly contribute to advancements in deep tissue imaging techniques and innovative microscopy methods, such as femtosecond fieldoscopy. This technique, currently being developed by Fattahi’s group, allows for capturing high spatial resolution, label-free images with attosecond temporal resolution. It opens up new possibilities for precise manipulations in the central nervous system through light-based interventions.
The collaboration between the fields of physics and biology is highlighted in this study, showcasing the value of interdisciplinary partnerships in advancing scientific knowledge. These findings not only shed light on photodamage mechanisms in living organisms but also pave the way for potential in vivo applications that enable precise manipulation of the central nervous system. This research signifies a step forward in understanding the impact of nonlinear light microscopy on biological processes.