The head-direction signal is generated from two types of head direction cells in brainstem nuclei

Head direction (HD) cells discharge based on an animal’s directional heading. Computational models propose that a ring-attractor network across the connections between the lateral mammillary (LMN) and dorsal tegmental nuclei (DTN) underlies the signal’s generation. These models contain neurons that encode either HD or angular head velocity (AHV), but also require cells that are sensitive to both parameters conjunctively (HD + AHV). Here we identify both types of HD cells in the LMN and DTN of female rats, with one population sensitive to AHV (both symmetric and asymmetric), and the other population insensitive to AHV. Notably, many HD + AHV cells are also sensitive to the animal’s linear head-speed (LHS). In contrast, anterodorsal thalamic HD cells are rarely sensitive to AHV or LHS. These findings demonstrate that the requisite HD + AHV cell is present in areas that generate the HD signal and supports the view that a ring attractor network underlies its generation in mammals. The mechanisms generating the head direction cell signal in rats are not fully understood. Here, two distinct types of head direction cells in the lateral mammillary and dorsal tegmental nuclei were identified: one type is angular head velocity independent, while the second type depends on the animal’s angular head velocity.