Prof. Pier Giorgio Montarolo
Lines of research
The group studies the synaptic plasticity ad synapse formation. For this
purpose we are using as experimetal model identified monosynaptic circuits
re-established in colture from Aplysia californica and Helix pomatia. We
are using the monosynaptic component of the gill withdrawal reflex of Aplysia
to study the morphological changes that accompany long-term (more than
24 hrs) synaptic plasticity such as long-term facilitation and long-term
depression of synaptic strength. These in vitro long-lasting synaptic changes
are induced by applications of specific neuromodulators. The extent of
synaptic transmission is tested by standard intracellular recording techniques.
The morphological changes are measured by fluorescent probes intracellularly
injected in the presynaptic neurons and with the aid of low light level
digital videomicroscopy. An analogous monosynaptic circuit form ground
mollusk Helix pomatia has been developed. In a second line of research
we study the influence of the presence of the post-synaptic neuron on the
phenotype of the presynaptic terminals. As experimental model we use the
B2 neuron as target positioned close to the branches of the presynaptic
bipolar serotoninergic MGC neuron from terrestrial snail Helix pomatia.
We are using two idexes of presynaptic maturation. The number of synaptic
boutons (varicosities) and action potential Ca++ accumulation. Both measures
were done either in the presence or in the absence of the target neuron.
The varicosities are identified by using antibodies against synaptic vescicle
protein synaptotagmin and presynaptic neurotransmitter serotonine. Intracellular
calcium levels is measured by calcium-sensitive, membrane -impermeable
pentapotassium salt of fura-2 intracellular injected.
