Mossy fiber synapses form the major excitatory input into the autoassociative network of pyramidal cells in the CA3 area of the hippocampus. Here we demonstrate that at the mossy fiber synapses, glutamate and gamma-aminobutyric acid (GABA) act as autaptic and heterosynaptic presynaptic inhibitory transmitters through metabotropic glutamate receptors (mGluRs) and GABAB receptors, respectively. B...

Long-term potentiation (LTP) is a cellular model of synaptic plasticity and reflects an increase of synaptic strength. LTP is also present in the nociceptive system and is believed to be one of the key mechanisms involved in the manifestations of chronic pain. LTP manifested as an increased response in pain perception can be induced in humans using high-frequency electrical stimulation (HFS). T...

Early growth response (Egr) transcription factors (Egr1 to Egr4) are synaptic activity-inducible immediate early genes (IEGs) that regulate some aspects of synaptic plasticity-related to learning and memory, yet the target genes regulated by them are unknown. In particular, Egr1 is essential for persistence of late-phase long-term potentiation (L-LTP), for hippocampus-dependent long-term memory...

Long-term potentiation (LTP), a persistent enhancement of synaptic transmission that may be involved in some forms of learning and memory, is induced at excitatory synapses in the CA1 region of the hippocampus by coincident presynaptic and postsynaptic activity. Although action potentials back-propagating into dendrites of hippocampal pyramidal cells provide sufficient postsynaptic activity to ...

The effects of brain-derived neurotrophic factor (BDNF) were investigated on synaptic transmission and two forms of activity-dependent synaptic plasticity, long-term potentiation (LTP) and long-term depression (LTD), in visual cortex slices prepared from young (P21 -28) rats. The slices treated for 2-5 h in BDNF showed no difference from control slices when a 'strong' tetanus was used (theta-bu...

Repetitive activation of glutamatergic fibers that normally induces long-term potentiation (LTP) at excitatory synapses in the hippocampus also triggers long-term depression at inhibitory synapses (I-LTD) via retrograde endocannabinoid signaling. Little is known, however, about the physiological significance of I-LTD. Here, we show that synaptic-driven release of endocannabinoids is a highly lo...

OBJECTIVE To investigate the effect of neurogulin-1 (NRG1) on the transmission and plasticity of CA1 synapses in mouse hippocampal slices at different temperatures. METHODS Under room temperature (26-/+1 degrees C) or physiological temperature (32-/+1 degrees C), field excitatory postsynaptic potential (fEPSP) evoked by extracellular microelectrode recording technique was recorded in the CA1 ...

We identified the Grp gene, encoding gastrin-releasing peptide, as being highly expressed both in the lateral nucleus of the amygdala, the nucleus where associations for Pavlovian learned fear are formed, and in the regions that convey fearful auditory information to the lateral nucleus. Moreover, we found that GRP receptor (GRPR) is expressed in GABAergic interneurons of the lateral nucleus. G...

The repetition of experience is often necessary to establish long-lasting memory. However, the cellular mechanisms underlying this repetition-dependent consolidation of memory remain unclear. We previously observed in organotypic slice cultures of the rodent hippocampus that repeated inductions of long-term potentiation (LTP) led to a slowly developing long-lasting synaptic enhancement coupled ...

NMDA receptors are important for synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD). To help investigate the precise location of the NMDA receptors that are required for different types of synaptic plasticity, we synthesized a caged form of the use-dependent NMDA receptor antagonist MK801, which we loaded into individual neurons in vitro, followed by comp...