Xu et al. from Dr. Ileana Hanganu-Opatz lab used NeuroNexus acute one-shank optoelectrodes (A1x16-5mm-100-703-OA16LP; A1x16-5mm-50-703-OA16LP) and four-shank optoelectrodes (A4x4-3mm-100-125-703-OA16LP) to target and span recording sites across lateral entorhinal cortex (LEC), CA1 area of the hippocampus (HP), and the prelimbic subdivision of prefrontal cortex (PFC), respectively. Their results uncover novel mechanisms of miswiring in the neonatal brain and highlight the critical role of the LEC for the function of prefrontal-hippocampal circuits.