A discrete model of multitransmitter interactions between neurons in a common extracellular space (ECS) is proposed. Neurons in the model are heterogeneous in three different senses. They differ in (i) the type of endogenous change in the membrane potential, (ii) the type of secreted neurotransmitter, and (iii) the set of receptors, wherein each receptor is sensitive to a particular neurotransmitter. The model is characterized by the broadcast nature transmission of the signals: the neurotransmitter appeared in the ECS is treated as an input signal for all neurons with receptors sensitive to it. It is shown that the extrasynaptic interaction of neurons combined with multitransmitter environment enables to reproduce the rhythms generated by simple natural neural networks.