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Caffeine-mediated presynaptic long-term potentiation in hippocampal CA1 pyramidal neurons.
- Source :
-
Journal of neurophysiology [J Neurophysiol] 2003 Jun; Vol. 89 (6), pp. 3029-38. - Publication Year :
- 2003
-
Abstract
- We report a new form of long-term potentiation (LTP) in Schaffer collateral (SC)-CA1 pyramidal neuron synapses that originates presynaptically and does not require N-methyl-d-aspartate (NMDA) receptor activation nor increases in postsynaptic-free Ca2+. Using rat hippocampal slices, application of a brief "pulse" of caffeine in the bath evoked a nondecremental LTP (CAFLTP) of SC excitatory postsynaptic currents. An increased probability of transmitter release paralleled the CAFLTP, suggesting that it originated presynaptically. The P1 adenosine receptor antagonist 8-cyclopentyltheophylline and the P2 purinoreceptor antagonists suramin and piridoxal-5'-phosphate-azophenyl 2',4'-disulphonate blocked the CAFLTP. Inhibition of Ca2+ release from caffeine/ryanodine stores by bath-applied ryanodine inhibited the CAFLTP, but ryanodine in the pipette solution was ineffective, suggesting a presynaptic effect of ryanodine. Previous induction of the "classical" LTP did not prevent the CAFLTP, suggesting that the LTP and the CAFLTP have different underlying cellular mechanisms. The CAFLTP is insensitive to the block of NMDA receptors by 2-amino-5-phosphonopentanoic acid and to Ca2+ chelation with intracellular 1,2-bis (2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid, indicating that neither postsynaptic NMDA receptors nor increases in cytosolic-free Ca2+ participate in the CAFLTP. We conclude that the CAFLTP requires the interaction of caffeine with presynaptic P1, P2 purinoreceptors, and ryanodine receptors and is caused by an increased probability of glutamate release at SC terminals.
- Subjects :
- Animals
Electrophysiology
Glutamic Acid physiology
Hippocampus drug effects
Patch-Clamp Techniques
Phosphodiesterase Inhibitors pharmacology
Presynaptic Terminals drug effects
Pyramidal Cells drug effects
Rats
Rats, Wistar
Receptors, N-Methyl-D-Aspartate physiology
Receptors, Purinergic P1 physiology
Receptors, Purinergic P2 physiology
Ryanodine Receptor Calcium Release Channel physiology
Caffeine pharmacology
Central Nervous System Stimulants pharmacology
Hippocampus physiology
Long-Term Potentiation drug effects
Presynaptic Terminals physiology
Pyramidal Cells physiology
Synaptic Transmission drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0022-3077
- Volume :
- 89
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Journal of neurophysiology
- Publication Type :
- Academic Journal
- Accession number :
- 12783948
- Full Text :
- https://doi.org/10.1152/jn.00601.2002