Previously, we reported that hippocampal pyramidal neurons exhibited differential spatial and event related firing patterns while rats retrieved rewards from different locations in the same environment (Smith et al, 2002, SFN abs 677.11). These differential firing patterns could serve as a context code that would be useful in disambiguating similar contexts that require different behavioral responses. Although most electrophysiological studies of hippocampal function have examined pyramidal neurons, recent findings indicate that high rate, presumptive inhibitory interneurons can also exhibit task relevant responses (Wiebe and Staubli, 2001, J Neurosci, 21(11) 3955-67). Here, we examined the role of these high rate neurons in context processing using our previously employed learning task. Neuronal activity was recorded while rats (n=11) learned to retrieve rewards at one location on a plus maze for the first block of a session and from a different location during the second block. Both blocks took place in ...