The essentiality of neuronal connections can be seen by the frenetic activity which dissociated neurons in culture exhibit in an attempt to re-establish functional connections. Through these interactions, neurons gain access to trophic factors, such as nerve growth factor, which determine whether they live or die. Connection and successful interaction with others is thus a biological imperative for neurons. The properties of a given neuron are determined both by the inherent genetic program and by changes in its genetic expression induced by cell-to-cell interaction. In other words, plasticity of neuronal function reflects not only cellular properties but is a consequence of its relationships. Since it is reasonable to assume that the emotional experience of organisms derives from the biological properties of their brain cells, it seems fruitful to probe the basic biology of these cells for metaphors that might yield insight into psychological properties. Clinical examples illustrate how using these concepts can enlighten the processes by which psychotherapeutic change can occur. In addition, perhaps understanding the underlying neurobiology can add scientific legitimacy to clinical psychodynamic work, and can reduce the tension between "biological" and "psychological" psychiatry. These ideas might be used to develop a new framework to strengthen the teaching of psychotherapy.