The human brain comprises about 86 billion neurons organized in well-defined spatial locations that define clusters of neurons (modules). Each cognitive and motor function is possible thanks to the correct interaction among them. The disruption, loss, or alteration of these connections can produce pathological conditions. To understand how the information is transmitted and computed, we need to investigate the communication among the different modules. Another essential feature to understand is how the electrophysiological signals are transmitted is the 3D spatial organization. Many studies make use of in vivo approach, with the obvious limit to study a well-specific circuit. The module activity we observe is always influenced by all its inputs. In this perspective, in vitro engineered models are a powerful tool. They reduce the complexity of the system, keeping the key features of the in vivo environment. In this work, we exploited polymeric masks coupled to Micro-Electrode Arrays to investigate the role of the key features of the human brain. Studying the cortical-hippocampal circuit, we observed a more scattered signal propagation and a higher segregation when the hippocampal population was present. Moreover, the inhibitory hippocampal connections strongly modulated the cortical activity. Finally, we introduced the three-dimensionality, recreating a wider pattern of activity. In perspective, we moved one more step towards recreating the mechanical properties of the extracellular matrix by building cortical and hippocampal assembloids, which are able to better reproduce the intrinsic characteristics of the native tissues. This new model can be exploited as platform for precision medicine.