Animals evaluate crucial external events, such as aversive stimuli and rewards. The hippocampus contains place cells that represent spaces, which are suggested to play a fundamental role in spatial processing. In our early study, we designed a T-maze alternation task for rats in which an aversive airpuff stimulation was applied at a specific location. Recording of spike patterns from the dorsal hippocampus revealed that the application of airpuff altered spatial firing activity of a certain population of neurons, suggesting that hippocampal spatial maps are flexibly reorganized to represent particular aversive events. On the other hand, the role of the ventral hippocampus remains to be elucidated. Ventral hippocampal neurons project to different extrahippocampal areas such as the amygdala and nucleus accumbens and encode different emotional states such as reward anticipation and fear. To further analyze their spike patterns, we simultaneously recorded spike patterns from dorsal and ventral hippocampus in rats performing a modified version of the T-maze task. Here, we present some typical spike patterns encoding places, reward, and aversive stimulation. Our results provide a new insight into neuronal mechanisms underlying information processing of spatial and aversive events along the dorso-ventral axis of the hippocampus.