EN
INTRODUCTION: The majority of excitatory synapses in the mammalian brain are accommodated at the dendritic spines. One of the most characteristic features of dendritic spines is their morphological diversity which reflect their function. It has been already shown that the size of dendritic spine also correlates with the numbers of vesicles containing neurotransmitter released from presynaptic part of a synapse. The new, recently described morphological form of dendritic spines is the formation of spine-head protrusion (SHP). The studies have already shown that exogenous iontophoretic application of glutamate to medium of organotypic hippocampal culture induces the formation of SHPs. On this basis, it is hypothesized that the formation of SHPs occurs as a result of the neurotransmitter release to the extracellular matrix. AIM(S): To determine the genesis of SHP formation in dissociated hippocampal culture. METHOD(S): Development of an electrochemical glutamate biosensor which enables long-term and continuously measurements of endogenous glutamate concentration in neuronal culture. RESULTS: Our results have shown that the formation of SHPs depends on proteolytic activity of matrix metalloproteinase 9 (MMP-9) and that SHPs are capable of creating new synaptic connections. CONCLUSIONS: Due to the fact that we believe that SHP plays an important role in synaptic plasticity, underlying learning and memory processes, we are focused on developing biosensor which enables to verify theory of SHP formation.