Following the same trends in other communication schemes, design of star network topologies will gain importance in order to communicate with a centralized hub in molecular communications as well. For a molecular communication multiple access network system, interlink interference (ILI) becomes a crucial issue in addition to intersymbol interference (ISI). This paper focuses on spatial allocation of the receptors of a centralized receiver among transmitters by proposing efficient solutions to reduce both ISI and ILI. The spatial allocation scheme has been designed using an optimization problem and verified with Monte Carlo simulations.