Place recognition responses of neurons in monkey hippocampus

Neuronal activity in the monkey hippocampus was recorded while the monkey sat in a rotatable cab which it could cause to move from one location to another by pressing bars, and while it was presented various visual stimulation from several horizontal directions (directional stimulation). Of 174 hippocampal neurons recorded, 20 were selective to direction of the stimulus without place relation. Responses of these neurons could be described in egocentric coordinates for some and allocentric coordinates for others. Seventy-seven neurons had place related activity (place related neurons). Of these place related neurons, 21 were also directionally selective with responses described in egocentric or allocentric coordinates or both. The results show close relations between the coding of environmental space cues in egocentric and allocentric coordinates, and place related activity in the primate hippocampus.