title: The flaginserter: a simple device for automatically marking events in video recordings.
abstract: Dynamic imaging of cellular responses often involves the use of standard video components. While these components (cameras, monitors, etc.) are relatively inexpensive and easily available, there is the difficulty of integrating them into experimental set-ups. Especially for video recordings of fast signals that occur in neurobiological preparations (e.g. synaptic responses), there is a critical need for accurate synchronisation of video images with external events, such as extracellular stimulation or intracellular depolarising voltage steps. We developed a circuit that allows such events within the video sequence to be marked by means of a white flag that is inserted into the video image. Depending on the mode of insertion, the time resolution is better than 17 ms or better than 65 micros (i.e. a single video field or video line, respectively). The circuit has been shown to work reliable in combination with video-rate confocal imaging and patch-clamp recordings.
authors.affiliation: Physiologisches Institut, Universität des Saarlandes, Homburg, Germany. phjeil@med-rz.uni-sb.de
authors.forename: J
authors.initials: J
authors.lastname: Eilers
authors.forename: D
authors.initials: D
authors.lastname: Hof
authors.forename: A
authors.initials: A
authors.lastname: Konnerth
mesh_terms: D000818:Animals; D001331:Automation / Q000295:instrumentation / Q000379:methods; D002118:Calcium / Q000378:metabolism; D003712:Dendrites / Q000502:physiology*; D004558:Electric Stimulation; D004867:Equipment Design; D019706:Excitatory Postsynaptic Potentials; D008856:Microscopy, Fluorescence; D018715:Microscopy, Video / Q000295:instrumentation* / Q000379:methods; D009412:Nerve Fibers / Q000502:physiology; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D015203:Reproducibility of Results; D013997:Time Factors; D014741:Video Recording / Q000295:instrumentation* / Q000379:methods
chemical_list: D002118:Calcium