Pablo Mendez

Interneuron diversity in hippocampal memory circuits 

Activity dependent changes in synaptic strength and structure are at the basis of the remarkable adaptive capability of mammalian brain. Recent studies showed that similarly to their excitatory (glutamatergic) counterparts, also Gamma-aminobutyric acid (GABA)-releasing inhibitory synapses can undergo activity-dependent functional and structural changes. Despite substantial experimental evidence, we have only partial knowledge of the implications of this type of plasticity for the function of inhibitory synapses and the circuits they form. In my talk, I will discuss experiments directed to understand the mechanisms and functional role of this phenomenon. I will discuss the consequences of plasticity on GABAergic and glutamatergic synapses on regulating the balance between excitation and inhibition and on the memory function of hippocampal neuronal ensembles. Since GABAergic synapses originate from a very heterogeneous population composed of a stunning diversity of different subtypes, I will also discuss the possibility that plasticity of the GABAergic synapses maybe associated to equally diverse properties governing layer distribution, spatial extent and molecular composition of the different inhibitory neuron subtypes.