PT - JOURNAL ARTICLE AU - Silva, Artur AU - CarriƧo, Paulo AU - Fernandes, Ana B. AU - Saraiva, Tatiana AU - Oliveira-Maia, Albino J. AU - da Silva, Joaquim Alves TI - High-Precision Optical Fiber-Based Lickometer AID - 10.1523/ENEURO.0189-24.2024 DP - 2024 Jul 01 TA - eneuro PG - ENEURO.0189-24.2024 VI - 11 IP - 7 4099 - http://www.eneuro.org/content/11/7/ENEURO.0189-24.2024.short 4100 - http://www.eneuro.org/content/11/7/ENEURO.0189-24.2024.full SO - eNeuro2024 Jul 01; 11 AB - Quantifying and analyzing licking behavior can offer valuable insights into fundamental neurobiological mechanisms controlling animal consummatory behaviors. Lickometers are typically based on electrical properties, a strategy that comes with limitations, including susceptibility to electrical interference and generation of electrical disturbances in electrophysiological measurements. While optical lickometers offer an alternative method to measure licks and quantify fluid intake in animals, they are prone to false readings and susceptibility to outside light sources. To overcome this problem, we propose a low-cost open-source lickometer that combines a restricted infrared beam defined by optical fibers, with a poke design that allows easy access to the tongue while limiting access of other body parts and external light sources. This device also includes features for detecting nose pokes and presenting visual cues during behavioral tasks. We provide validation experiments that demonstrate the optical lickometer's reliability, high-sensitivity and precision, and its application in a behavioral task, showcasing the potential of this tool to study lick microstructure in combination with other techniques, such as imaging of neural activity, in freely moving mice.