Ubiquitous molecular substrates for associative learning and activity-dependent neuronal facilitation.

Recent evidence suggests that many of the molecular cascades and substrates that contribute to learning-related forms of neuronal plasticity may be conserved across ostensibly disparate model systems. Notably, the facilitation of neuronal excitability and synaptic transmission that contribute to associative learning in Aplysia and Hermissenda, as well as associative LTP in hippocampal CA1 cells, all require (or are enhanced by) the convergence of a transient elevation in intracellular Ca2+ with transmitter binding to metabotropic cell-surface receptors. This temporal convergence of Ca2+ and G-protein-stimulated second-messenger cascades synergistically stimulates several classes of serine/threonine protein kinases, which in turn modulate receptor function or cell excitability through the phosphorylation of ion channels. We present a summary of the biophysical and molecular constituents of neuronal and synaptic facilitation in each of these three model systems. Although specific components of the underlying molecular cascades differ across these three systems, fundamental aspects of these cascades are widely conserved, leading to the conclusion that the conceptual semblance of these superficially disparate systems is far greater than is generally acknowledged. We suggest that the elucidation of mechanistic similarities between different systems will ultimately fulfill the goal of the model systems approach, that is, the description of critical and ubiquitous features of neuronal and synaptic events that contribute to memory induction

Detection and Diagnosis of PVY

International audienceThe worldwide prevalence of Potato virus Y (PVY) poses a continuous challenge to efficient potato production. The accurate diagnosis of viruses such as PVY is inherently challenging due to the broad biological and genetic diversity of PVY strains that elicit a range of symptoms and diseases in various potato cultivars and related solanaceous species. A wide range of techniques have been developed over a period of 50 years for the detection of PVY. Serological methods such as ELISA, using polyclonal and especially monoclonal antibodies, have been widely used by most diagnostic laboratories, due to their cost effectiveness and capacity to implement for a large number of samples. Over the last decade, PCR-based assays have been routinely used in diagnostic laboratories because of their sensitivity, specificity and their capacity to be automated for high-throughput testing. The objective of this chapter is to provide a brief historical overview of the main diag-nostic methods used to detect and identify PVY and to highlight those that are suit-able for either research or diagnostic purposes