Flexible Coupling of Respiration and Vocalizations with Locomotion and Head Movements in the Freely Behaving Rat

Figure 1

Recorded behavioral variables. Photograph of a male Long Evans rat, side view. The rat has a cannula with one end in the nasal cavity and the other over the cranium, with a ring magnet at its end. A wireless headstage carrying a pressure sensor and a 3-axis accelerometer is magnetically attached to the cannula. Throughout this work, respiration is intranasal pressure and and are the signals from the horizontal and vertical axes of the accelerometer. Ultrasonic vocalizations were recorded from ambient condenser microphones and instantaneous speed was measured from video tracking. Black arrows point to possible sources for the forces acting on the accelerometer: hindlimb and forelimb muscles, back/neck muscles, and changes in the decomposition of gravity from tilting of the head.