Neuroscience
-
Following training in a difficult olfactory-discrimination (OD) task rats acquire the capability to perform the task easily, with little effort. This new acquired skill, of 'learning how to learn' is termed 'rule learning'. At the single-cell level, rule learning is manifested in long-term enhancement of intrinsic neuronal excitability of piriform cortex (PC) pyramidal neurons, and in excitatory synaptic connections between these neurons to maintain cortical stability, such long-lasting increase in excitability must be accompanied by paralleled increase in inhibitory processes that would prevent hyper-excitable activation. ⋯ At the molecular level, such rule-learning-relevant synaptic strengthening is mediated by doubling the conductance of synaptic channels, but not their numbers. This post synaptic process is controlled by a whole-cell mechanism via particular second messenger systems. This whole-cell mechanism enables memory amplification when required and memory extinction when not relevant.