[Effect of dopamine on the background and evoked activity of interneurons from isolated spinal cord segments of newborn rats].
The effects of dopamine on the background and dorsal root stimulation-evoked activity of spinal interneurons and on the field potentials in the dorsal horn were studied in the isolated superfused spinal cord of 11-18 days old rats. It was established that application of dopamine in concentration 1.10(-6)-1.10(-3) mol/l caused exciting and depressing effects on the background and evoked activity of spinal cord cells. The postsynaptic wave of field potentials was depressed by dopamine. In some interneurons the effects of dopamine disappeared in the solution with 0.01 mmol/l Ca2+ and 1.5-2 mmol/l Mn2+ (trans-synaptic effects). In other cells exciting or inhibiting effects of dopamine were preserved in the medium blocking synaptic transmission, that evidenced for direct depolarization and hyperpolarization of the interneuron membrane. The effects of dopamine were reversible and dose-dependent. These results suggest that dopamine may have influence on the transmission of excitation in the spinal cord on the interneurons level. It is supposed to be possible that different types of interneurons responses are the result of the existence of two types of dopamine receptors in the spinal cord.
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D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D004298:Dopamine / Q000502:physiology*; D005071:Evoked Potentials; D066298:In Vitro Techniques; D007395:Interneurons / Q000502:physiology*; D051381:Rats; D013116:Spinal Cord / Q000502:physiology*
D004298:Dopamine
Vliianie dopamina na fonovuiu i vyzvanniui aktivnost' interneĭronov izolirovannogo segmenta spinnogo mozga krysiat.