Properties of 5-hydroxytryptamine3 receptor-gated currents in adult rat dorsal root ganglion neurones.
1. Responses to 5-hydroxytryptamine (5-HT) were examined on rat dorsal root ganglion (DRG) neurones maintained in tissue cultures, by use of whole cell recording techniques. 2. 5-HT (usually 10 microM) evoked a depolarization associated with an increase in membrane conductance in 40% of DRG neurones. There was a considerable variation in the size and persistence of this response between different batches of cells. 3. The 5-HT response was mimicked by applying the agonists 2-methyl-5-HT (10 microM) and phenylbiguanide (10 microM). Responses were blocked by ICS 205-930 (100 nM), but not by methysergide (0.1-1.0 microM). 4. 5-HT currents could be carried by sodium and caesium ions, but not by choline ions. The amplitude and duration of the 5-HT responses were dependent on the concentration of divalent cations in the extracellular solution: both became greater when calcium and magnesium concentrations were decreased. 5. Staurosporine, a putative antagonist of protein kinases, inhibited responses to 5-HT.
Robertson
B
B
Cellular Electrophysiology, Sandoz Institute for Medical Research, London.
Bevan
S
S
D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology; D002413:Cations, Divalent / Q000494:pharmacology; D002794:Choline / Q000494:pharmacology; D046508:Culture Techniques; D005727:Ganglia, Spinal / Q000378:metabolism* / Q000502:physiology; D007211:Indoles / Q000494:pharmacology; D015640:Ion Channel Gating / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D051381:Rats; D011985:Receptors, Serotonin / Q000378:metabolism*; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D019311:Staurosporine; D000077526:Tropisetron
D000470:Alkaloids; D002413:Cations, Divalent; D007211:Indoles; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D012701:Serotonin; D000077526:Tropisetron; C045918:2-methyl-5-HT; D011493:Protein Kinase C; D019311:Staurosporine; D002794:Choline; D002118:Calcium