Flexible Tube-Shaped Neural Probe for Recording and Optical Stimulation of Neurons at Arbitrary Depths

Transparent tube-shaped neural probes consisting of 8 recording areas on the surface of a cylinder and a movable optical fiber that is set in a groove of a stainless steel needle at the core have been developed. The recording areas are placed perpendicularly to the brain surface so that neural activities can be recorded across cortical layers. The movable metal needle with optical fiber enables optical stimulation of neurons surrounding the recording areas at any depth in the cortex. The neural probe was fabricated and examined for its applicability in optogenetic studies in neuroscience. The fabricated probe successfully recorded neural activities from the cortex of an anesthetized animal while optical stimulation was delivered successively at any depth of the cortex. Distinct neural activation patterns depending on the depth of optical stimulation were found. It was confirmed that the fabricated probe is suitable for optical manipulation for analysis of neural activities across cortical layers and simultaneously monitoring the effects of stimulation on neural activities.