The hippocampus' role in spatial cognition is well-established, with place cells encoding environmental spatial information and interneurons modulating neural circuitry. Our research explores the role of NEIL3, a DNA glycosylase, in hippocampal neural processing. To determine the role of NEIL3 in the functioning of hippocampal neurons, we conducted in-vivo electrophysiological recordings to measure the activity of place cells and inhibitory interneurons in the hippocampus of both wild-type mice and mice lacking NEIL3 (Neil3-/-). We found that NEIL3-deficient CA1 place cells maintain normal spatial activity and remapping capabilities. However, these cells displayed a significant impairment in long-term spatial stability, suggesting a role for NEIL3 in memory consolidation. The analysis of hippocampal neural oscillations revealed decreased power in the slow gamma oscillatory band in the Neil3-/-hippocampus, suggesting that NEIL3 impacts the modulation of neural oscillations critical for cognitive functions. While it is known that interneurons influence neural oscillations, our study is the first to show that a NEIL3 deficiency can disrupt this regulation, indicating a novel aspect of NEIL3's role in hippocampal functionality. Collectively, this study offers new insights into NEIL3's impact on the hippocampal neuronal network, with broader implications for understanding the cellular basis of spatial memory and its deterioration with age or pathology.