2012/07/03 by Benjamin Migliori, Massimiliano Di Ventra, Migliori, Benjamin +3
Neuroscience · #Biological Physics (physics.bio-ph) #FOS: Biological sciences #FOS: Physical sciences #Neurobiology and Insect Physiology Research #Olfactory and Sensory Function Studies #Photoreceptor and optogenetics research #Quantitative Methods (q-bio.QM)
paper · pdf · doi:10.48550/arxiv.1207.0556
openalex publication_date 2012/07/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present a method for achieving temporally and spatially precise photoactivation of neurons without the need for genetic expression of photosensitive proteins. Our method depends upon conduction of thermal energy via absorption by a dye or carbon particles and does not require the presence of voltage-gated channels to create transmembrane currents. We demonstrate photothermal initiation of action potentials in Hirudo verbana neurons and of transmembrane currents in Xenopus oocytes. Thermal energy is delivered by focused 50 ms, 650 nm laser pulses with total pulse energies between 250 and 3500 \muJ. We document an optical delivery system for targeting specific neurons that can be expanded for multiple target sites. Our method achieves photoactivation reliably (70 - 90% of attempts) and can issue multiple pulses (6-9) with minimal changes to cellular properties as measured by intracellular recording. Direct photoactivation presents a significant step towards all-optical analysis of neural circuits in animals such as Hirudo verbana where genetic expression of photosensitive compounds is not feasible.