FMRF-amide modulates the electrical activity of the leech Retzius cell.
The effect of the peptide FMRF-amide on the electrical activity of the leech Retzius (R) cell was investigated using electrophysiological techniques. FMRF-amide and six structurally related analogs increased the excitability of the R cell in several distinct ways that could act in concert to modulate transmitter release. 'Puffs' of FMRF-amide transiently depolarized the cell leading to a barrage of action potentials. This depolarization was followed by a phase of rhythmical bursting that appeared intrinsic to the neuron. FMRF-amide also broadened the plateau of the Ca(2+)-dependent action potential. The results suggest that the terminal Phe and Arg as well as the C-terminal amide are critical for the activity of these peptides.
Sahley
C L
CL
Department of Biological Sciences, Purdue University, W. Lafayette, IN 47907.
Strong
J A
JA
Kleinhaus
A L
AL
D000200:Action Potentials / Q000187:drug effects; D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000502:physiology; D004594:Electrophysiology; D019835:FMRFamide; D007447:Invertebrate Hormones / Q000494:pharmacology*; D007865:Leeches / Q000502:physiology*; D008839:Microelectrodes; D008969:Molecular Sequence Data; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009479:Neuropeptides / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects
D007447:Invertebrate Hormones; D009479:Neuropeptides; D015221:Potassium Channels; D019835:FMRFamide; D002118:Calcium