Real time online data processing system for the e.e.g. and body movement during the lifetime of a freely moving mouse

Imaging local brain activity of multiple freely moving mice sharing the same environment

Electrophysiological field potential dynamics have been widely used to investigate brain functions and related psychiatric disorders. Considering recent demand for its applicability to freely moving subjects, especially for animals in a group and socially interacting with each other, here we propose a new method based on a bioluminescent voltage indicator LOTUS-V. Using our fiber-free recording method based on the LOTUS-V, we succeeded in capturing dynamic change of brain activity in freely moving mice. Because LOTUS-V is the ratiometric indicator, motion and head-angle artifacts were not significantly detected. Taking advantage of our method as a fiber-free system, we further succeeded in simultaneously recording from multiple independently-locomotive mice that were freely interacting with one another. Importantly, this enabled us to find that the primary visual cortex, a center of visual processing, was activated during the interaction of mice. This methodology may further facilitate a wide range of studies in neurobiology and psychiatry.

Doppler radar device as a useful tool to quantify the liveliness of the experimental animal

The Doppler radar device which is described here is shown to be a reliable and accurate device to quantify the liveliness of an experimental rat. During recording the animal did not seem to be disturbed in any way by the device. It could stay in its normal cage, move freely, walk around and eat and drink ad libitum. Measurement did not require extra light, sound or other stimuli. Interpretation of the data was easy. The computer which samples the Doppler radar output signal generates activity curves which were easily interpreted for different ranges of vitality, varying between high liveliness and apnoea or cardiac arrest. The apparatus is low priced, and simple to build and use.

Method of dynamic behavioral stage analysis (DBSAM) in the free moving mouse

The process of analysis involved in DBSAM was described based on both the processing flow and the acquired model data. In the first step, the behavior of a mouse was classified into moving stage (MV), deep sleep stage (EP) and OT stage, in which the brain activity of the mouse was near the consciousness level. In the second step, the vague OT stages were classified into stages of quietness during the wakefulness state (QU) and light sleep stages (LSP) by the logical matrix. Finally, the symbol presentation for the stage-linkage of multiple stages per 1 sec was demonstrated.