The hippocampus constructs a cognitive map for spatial and mental navigation, whose fundamental units are the place fields of pyramidal cells. Prevailing models attribute place field generation and flexibility (remapping) to excitatory circuits and their synaptic plasticity. In contrast, an alternative hypothesis posits that diverse inhibitory microcircuits critically shape place field properties through their family-specific, cooperative control of pyramidal neurons. However, testing this model has been technically challenging, as it requires simultaneously recording multiple interneuron types—a capability beyond the reach of conventional methods, which typically target only one or two families. Valero et al. recently overcame this limitation in Science by developing a machine-learning classifier that identifies interneuron families in large-scale recordings based on optogenetically tagged physiological features. By combining this classification with targeted manipulation, the authors demonstrated that interneuron families differentially and cooperatively regulate the place field properties of pyramidal neurons.
Cao et al. (Wed,) studied this question.