It is unknown how thalamic head direction neurons extract meaningful information from multiple conflicting sensory information sources when animals run under conditions of sensory mismatch. In the present study, rats were placed on a treadmill on a stage that moved in a figure-8-shaped pathway. The anterodorsal and laterodorsal neurons were recorded under two conditions: (1) control sessions, in which both the stage and the treadmill moved forward, or (2) backward (mismatch) sessions, in which the stage was moved backward while the rats ran forward on the treadmill. Of the 222 thalamic neurons recorded, 55 showed differential responses to the directions to window (south) and door (north) sides, along which the animals were translocated in the long axis of the trajectory. Of these 55 direction-related neurons, 15 showed heading direction-dependent responses regardless of movement direction (forward or backward movements). Thirteen neurons displayed heading and movement direction-dependent responses, and, of these 13, activity of 6 neurons increased during forward movement to the window or door side, while activity of the remaining 7 neurons increased during backward movement to the window or door side. Eighteen neurons showed movement direction-related responses regardless of heading direction. Furthermore, activity of some direction-related neurons increased only in a specific trajectory. These results suggested that the activity of these neurons reflects complex combinations of facing direction (landmarks), movement direction (optic flow/vestibular information), motor/proprioceptive information, and the trajectory of the movement.

SUMMARY:Recently, the curriculum and the educational methodologies associated with health sciences courses are being reviewed and adapted. Pre-clinical sciences, such as anatomy and embryology are as well subjected to those changes. In human embryology courses it is common to use models to represent the different phases of development to facilitate learning, since the students can see and touch the models, obtaining knowledge by analogies. The purpose of the present study was to investigate if the construction of models by the students during practical embryology classes would improve or facilitate their learning. One year after the classes, 60 students answered a questionnaire with nine objective questions, including spaces for suggestions and observations. The student's responses suggested that the construction of models contributed to their learning.