Long-term potentiation at single fiber inputs to hippocampal CA1 pyramidal cells.
AUTOR(ES)
Isaac, J T
RESUMO
Despite extensive investigation, it remains unclear whether presynaptic and/or postsynaptic modifications are primarily responsible for the expression of long-term potentiation (LTP) in the CA1 region of the hippocampus. Here we address this issue by using techniques that maximize the likelihood of stimulating a single axon and thereby presumably a single synapse before and after the induction of LTP. Several basic properties of synaptic transmission were examined including the probability of neurotransmitter release (Pr), the quantal size (q), and the so-called potency, which is defined as the average size of the synaptic response when release of transmitter does occur. LTP was routinely associated with an increase in potency, whereas increases in Pr alone were not observed. LTP was also reliably induced when baseline Pr was high, indicating that synapses with high Pr can express LTP. These results suggest that the mechanism for the expression of LTP involves an increase in q and is difficult to explain by an increase in Pr alone.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=38738Documentos Relacionados
- The synaptic glycoprotein neuroplastin is involved in long-term potentiation at hippocampal CA1 synapses
- Synaptic disinhibition during maintenance of long-term potentiation in the CA1 hippocampal subfield.
- Frequency-dependent associative long-term potentiation at the hippocampal mossy fiber-CA3 synapse.
- Classical conditioning induces long-term translocation of protein kinase C in rabbit hippocampal CA1 cells.
- Long-term potentiation in commissural and Schaffer projections to hippocampal CA1 cells: an in vivo study in the rat.