?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Three+modes+of+repetitive+firing+and+the+role+of+threshold+time+course+between+spikes.&rft.creator=Calvin%2C+William+H&rft.subject=Neurology&rft.description=When+rhythmic+firing+is+elicited+in+cat+spinal+motoneurons+by+long-lasting+depolarizing+currents%2C+the+'threshold'+voltage+from+which+each+spike+arises+may+appear+to+be+quite+constant+(Fig.+1A%2C+arrow).+If+one+probes+for+the+threshold+during+the+interspike+interval+(ISI)%2C+however%2C+it+is+seen+to+fall+well+below+this+level%2C+rising+towards+it+later+in+the+ISI.+Exceptionally+large+depolarizing+afterpotentials+may+intersect+this+threshold+time+course+shortly+after+a+spike%2C+causing+an+extra+spike.+The+extra+spike+itself+may+also+similarly+produce+another+extra+spike%3B+thus+a+regenerative+cycle+may+produce+a+burst+of+spikes+at+a+high+firing+rate.&rft.date=1974-12&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=text%2Fhtml&rft.identifier=http%3A%2F%2Fcogprints.org%2F18%2F1%2F1974BrainRes.htm&rft.identifier=++Calvin%2C+William+H++(1974)+Three+modes+of+repetitive+firing+and+the+role+of+threshold+time+course+between+spikes.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F18%2F