Figure 2:

Dome subsystems. (A) Dome shell and support legs. Note that a sectioned view of the shell is shown. The support legs are anchored to the floor of the laboratory, and the shell can pivot on the support legs. The handle, control cable and latch are used to lock or pivot the Dome. (B) Projection system. The plane mirror can be tilted in two axes using control knobs; this can be used to adjust image alignment. The top hat blocks the view of the rat above the Dome, and the collar blocks its view of the spherical mirror. Figure is to scale. (C) Side view. A camera is mounted above the top hat to view and track the rat. The central pillar is rotated using a motor and gear system. Control signals (e.g. for feeding) can be sent to, and neural signals can be received from, the rotating central pillar through a commutator placed beneath the central pillar. A white-noise producing speaker is placed at the bottom center of the apparatus. Figure is to scale. (D) Table top. The rats runs in the enclosed region between the front and back boom arms. The recording tether is laid out along the back boom arm, whereas the feed tube is routed along the front arm. The feed assembly is mounted on the rotating central pillar.