The impact of receptor-receptor interactions in heteroreceptor complexes on brain plasticity.

Allosteric mechanisms in receptor heteromers markedly increase the repertoire of receptor recognition and signaling. Of high importance is the altered function in the receptor heteromer versus the receptor homomer. Such a change in receptor function is mainly brought about by agonist induced allosteric receptor-receptor interactions and leads to functional and structural plasticity. Receptor-receptor interactions integrating synaptic and volume transmission signals participate in a significant way in modulating bidirectional synaptic plasticity and thus Hebbian plasticity. One molecular mechanism that can contribute to a change of synaptic weight may be represented by multiple interactions between plasma membrane receptors forming higher order heteroreceptor complexes via oligomerization at the pre- and post-junctional level. Such long-lived heteroreceptor complexes may play a significant role in learning and memory.