This study investigates the neural mechanisms underlying theta phase coding in hippocampal place cells, focusing on firing rate adaptation within a continuous attractor neural network (CANN). The authors demonstrate that firing rate adaptation causes the neural activity bump to oscillate around the external input, resembling theta sweeps of decoded position during locomotion. These forward and backward sweeps naturally account for theta phase precession and procession of individual neurons. By tuning the adaptation strength, the model explains the difference between 'bimodal cells' showing interleaved phase precession and procession, and 'unimodal cells' where phase precession predominates. The model also explains the constant cycling of theta sweeps along different arms in a T-maze environment, the speed modulation of place cell firing frequency, and the continued phase shift after transient silencing of the hippocampus. The study provides valuable insights into the neural mechanisms supporting theta phase coding in the brain, contributing to our understanding of hippocampal dynamics and their computational functions.This study investigates the neural mechanisms underlying theta phase coding in hippocampal place cells, focusing on firing rate adaptation within a continuous attractor neural network (CANN). The authors demonstrate that firing rate adaptation causes the neural activity bump to oscillate around the external input, resembling theta sweeps of decoded position during locomotion. These forward and backward sweeps naturally account for theta phase precession and procession of individual neurons. By tuning the adaptation strength, the model explains the difference between 'bimodal cells' showing interleaved phase precession and procession, and 'unimodal cells' where phase precession predominates. The model also explains the constant cycling of theta sweeps along different arms in a T-maze environment, the speed modulation of place cell firing frequency, and the continued phase shift after transient silencing of the hippocampus. The study provides valuable insights into the neural mechanisms supporting theta phase coding in the brain, contributing to our understanding of hippocampal dynamics and their computational functions.