Protracted presynaptic activity can induce long-term potentiation (LTP) or long-term depression (LTD) of the synaptic strength. However, virtually all the experiments testing how LTP and LTD depend on the conditioning input are carried out with trains of stimuli at constant frequencies, whereas neurons in vivo most likely experience a stochastic variation of interstimulus intervals. We used a c...

The ability to change behavior likely depends on the selective strengthening and weakening of brain synapses. The cellular models of synaptic plasticity, long-term potentiation (LTP) and depression (LTD) of synaptic strength, can be expressed by the synaptic insertion or removal of AMPA receptors (AMPARs), respectively. We here present an overview of studies that have used animal models to show...

Long-term environmental enrichment (EE) elicits enduring effects on the adult brain, including altered synaptic plasticity. Synaptic plasticity may underlie memory formation and includes robust (>24 h) and weak (<2 h) forms of long-term potentiation (LTP) and long-term depression (LTD). Most studies of the effect of EE on synaptic efficacy have examined the consequences of very prolonged EE-exp...

On February 12th 1973, Bliss and Lomo submitted their findings on activity-dependent plasticity of glutamatergic synapses. After this groundbreaking discovery, long-term potentiation (LTP) and depression (LTD) gained center stage in the study of learning, memory, and experience-dependent refinement of neural circuits. While LTP and LTD are extensively studied and their relevance to brain functi...

Long-term potentiation (LTP), a cellular model of learning and memory, is generally regarded as a unitary phenomenon that alters the strength of synaptic transmission by increasing the postsynaptic response to the release of a quantum of neurotransmitter. LTP, at CA3-CA1 synapses in the hippocampus, contains a stimulation-labile phase of short-term potentiation (STP, or transient LTP, t-LTP) th...

To examine changes in corticostriatal synaptic transmission in rats with ethanol withdrawal syndrome, intracellular and extracellular responses to subcortical white matter stimulation were recorded in neostriatal slice preparations. The resting membrane potential, input resistance and depolarizing postsynaptic potentials to single cortical white matter stimulation were similar in the neostriatu...

I n t r o d u c t i o n Memory storage in the mammalian brain is commonly divided into at least two distinct temporal phases: short-term memory, lasting minutes to hours, and long-term memory, which can persist for days, weeks, or even years (for review, see Polster et al. 1991). Whereas short-term memory requires only covalent modifications of pre existing proteins, long-term memory requires t...

The selective localization of protein synthetic machinery at postsynaptic sites makes it possible for the synthesis of particular proteins to be regulated by synaptic signals. Here we consider how the structure of the machinery constrains synthetic capacity and the evidence that mRNA translation is locally controlled by synaptic signals. Since the discovery of protein synthetic machinery at syn...

Long-term potentiation (LTP) requires postsynaptic depolarization that can result from EPSPs paired with action potentials or larger EPSPs that trigger dendritic spikes. We explored the relative contribution of these sources of depolarization to LTP induction during synaptically driven action potential firing in hippocampal CA1 pyramidal neurons. Pairing of a weak test input with a strong input...

Synaptic plasticity, the activity-dependent modification of synaptic strength, plays a fundamental role in learning and memory as well as in developmental maturation of neuronal circuitry. However, how synaptic plasticity is induced and regulated remains poorly understood. In this issue of The EMBO Journal, Yang and colleagues present sets of exciting data, suggesting that G-proteincoupled rece...