Neocortical and hippocampal networks in rodents exhibit synchronized oscillations during sleep, which may play a role in memory consolidation. This study shows that neuronal discharges in the somatosensory cortex and hippocampus are temporally linked on both slow and fine time scales. Neocortical bursts, associated with sleep spindles and delta waves, effectively trigger hippocampal discharges related to ripple oscillations. These oscillations may coordinate information transfer between neocortical and hippocampal cell assemblies during slow wave sleep. The study used multisite recordings in the hippocampus and somatosensory cortex to investigate the temporal coupling of neuronal activity. Neocortical activity can time the occurrence of hippocampal sharp waves and ripples. This coupling may assist in linking neocortical and hippocampal cell assemblies during slow wave sleep. The results show a robust temporal relationship between neocortical and hippocampal activity on both slow and fine time scales. Neocortical activity precedes hippocampal discharges, and this relationship is consistent during ripples, spindles, and delta waves. CSD analysis confirmed that neocortical activity can reach the hippocampus via entorhinal input. Neocortical spindles and delta waves are associated with rhythmic phase-locking of CA1 unit activity and delayed discharge of hippocampal neurons. The findings suggest that neocortical activity modulates hippocampal activity, which may be important for memory consolidation. The temporal relationship between neocortical and hippocampal activity provides a framework for coordinated information transfer between the two structures. This coupling may strengthen the coalition between neocortical and hippocampal cell assemblies during sleep.Neocortical and hippocampal networks in rodents exhibit synchronized oscillations during sleep, which may play a role in memory consolidation. This study shows that neuronal discharges in the somatosensory cortex and hippocampus are temporally linked on both slow and fine time scales. Neocortical bursts, associated with sleep spindles and delta waves, effectively trigger hippocampal discharges related to ripple oscillations. These oscillations may coordinate information transfer between neocortical and hippocampal cell assemblies during slow wave sleep. The study used multisite recordings in the hippocampus and somatosensory cortex to investigate the temporal coupling of neuronal activity. Neocortical activity can time the occurrence of hippocampal sharp waves and ripples. This coupling may assist in linking neocortical and hippocampal cell assemblies during slow wave sleep. The results show a robust temporal relationship between neocortical and hippocampal activity on both slow and fine time scales. Neocortical activity precedes hippocampal discharges, and this relationship is consistent during ripples, spindles, and delta waves. CSD analysis confirmed that neocortical activity can reach the hippocampus via entorhinal input. Neocortical spindles and delta waves are associated with rhythmic phase-locking of CA1 unit activity and delayed discharge of hippocampal neurons. The findings suggest that neocortical activity modulates hippocampal activity, which may be important for memory consolidation. The temporal relationship between neocortical and hippocampal activity provides a framework for coordinated information transfer between the two structures. This coupling may strengthen the coalition between neocortical and hippocampal cell assemblies during sleep.