Topic: channelrhodopsins

Three complementary lectures explain the development and applications of optogenetics. Gero Miesenböck traces optical control of neuronal activity from early experiments to studies of sleep, including neurons that respond to accumulated sleep need and molecular mechanisms governing sleep pressure. Peter Hegemann connects microbial photobiology to channelrhodopsins that control neuronal membrane voltage. He discusses their use in studying development and learning, and prospects for extending optical control to enzymes, transcription and translation. Georg Nagel follows the discovery and expre

Compared to mice, similar genetic tools have been traditionally very limited in rats, such that selective imaging or manipulation of circuits has been challenging. Developing blood-brain barrier (BBB) crossing and cell-type specific AAVs is an important research avenue as these viral vectors allow more precise control over transduction sparseness and coverage of larger target areas upon minimally invasive intravenous delivery (e.g. tail injections). One example of such an AAV is CAP-Mac, previously shown to be highly neuron-specific and to have high transduction efficiency in non-human primate

Rodents show pronounced local field potential (LFP) oscillations in the theta frequency range (7-12Hz in rodents) during exploration. Theta frequencies are thought to take part in memory processing by ensuring accurate sequences of neuron firing to facilitate plasticity processes. Many principal neurons in the parahippocampal areas, such as grid cells and place cells, show pronounced theta modulation. Grid cells in the medial entorhinal cortex (MEC) are theta modulated during active wakefulness, with power and frequency correlating to e.g. running speed or environmental familiarity. Suppressin