Subject(s)
Chloride Channels/physiology , Lampreys/physiology , Neurons/physiology , Spinal Cord/physiology , gamma-Aminobutyric Acid/physiology , Animals , In Vitro Techniques , Neurons/drug effects , Patch-Clamp Techniques , Receptors, GABA-A/drug effects , Receptors, GABA-A/physiology , Receptors, GABA-B/drug effects , Receptors, GABA-B/physiology , Spinal Cord/cytology , Spinal Cord/drug effects , gamma-Aminobutyric Acid/pharmacologyABSTRACT
GABA and GABAB receptor agonists were shown to reduce the peak calcium current amplitude with its subsequent recovery, whereas glycine and taurine, the GABAA receptor agonists, did not modify the current. The findings suggest that the GABAB receptors mediate a presynaptic inhibition by suppression of the Calcium currents in the cyclostome spinal cord.
Subject(s)
Calcium Channels/physiology , Receptors, GABA-B/physiology , Spinal Cord/physiology , Action Potentials/drug effects , Action Potentials/physiology , Animals , Barium/metabolism , Calcium Channels/drug effects , GABA Agonists/pharmacology , GABA Antagonists/pharmacology , In Vitro Techniques , Lampreys , Neurons/drug effects , Neurons/physiology , Patch-Clamp Techniques , Receptors, GABA-A/drug effects , Receptors, GABA-B/drug effects , Spinal Cord/cytology , Spinal Cord/drug effects , gamma-Aminobutyric Acid/pharmacologyABSTRACT
delta-Baclofen reduced the peak amplitude of the barium current in the DSCs from Lunicuspis and L.fluviatilis. The membrane conductance was not altered either by baclofen or GABA. The reducing effect could be abolished with delta-aminovaleric acid or 2(OH)saclofen. The data obtained suggest presence of the GABAB receptors in the DSC membranes. Functional role of the GABAB receptors in primary afferent cells of cyclostomes, is discussed.
