Platelet-activating factor contributes to the induction of long-term potentiation in the rat somatosensory cortex in vitro.
The contribution of platelet-activating factor (PAF) to the induction of neocortical LTP was examined in rat brain slices containing the primary somatosensory cortex (SI). Field potentials evoked by single pulse stimulation in cortical layer IV were recorded from layer II/III. In control experiments, tetanic high frequency stimulation (HFS) resulted in input-specific, NMDA receptor-dependent LTP (21.1+/-3.2%; mean+/-SEM; n=15; P<0.001). BN-52021 (5 microM), an antagonist at the extracellular PAF receptor, weakened the HFS-induced LTP to 12.4+/-2.7% (n=11; P<0.05). In contrast, HFS-induced LTP was significantly enhanced to 29.4+/-2.3% (n=11; P<0.05) when brain slices were superfused with ACSF containing the PAF receptor-agonist C-PAF (1.5 microM). The difference between LTP weakened by BN-52021 and LTP enhanced by C-PAF was highly significant (P<0.0005). These results suggest a physiological contribution of PAF to the induction of LTP in neocortical area SI. This contribution of PAF is mediated by an action at extracellular receptor sites.
Heusler
Peter
P
Institute of Physiology and Pathophysiology, Johannes Gutenberg University, Duesbergweg 6, D-55099 Mainz, Germany.
Boehmer
Gerd
G
D000818:Animals; D004558:Electric Stimulation / Q000379:methods; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects* / Q000528:radiation effects; D008297:Male; D010972:Platelet Activating Factor / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013003:Somatosensory Cortex / Q000187:drug effects*; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology
D018690:Excitatory Amino Acid Agonists; D010972:Platelet Activating Factor; C056639:2-amino-5-phosphopentanoic acid; D014633:Valine