Title

Calcium Currents and GABAB Receptors in the Dorsal Sensory Cells of the Lamprey Spinal Cord

Document Type

Article

Language

eng

Format of Original

11 p.

Publication Date

1-1999

Publisher

Springer

Source Publication

Neuroscience and Behavioral Physiology

Source ISSN

0097-0549

Abstract

Patch-clamp studies were performed on the isolated dorsal sensory cells of the spinal cords of three species of lamprey,Ichthyomyzon unicuspis, Petromyzon marinus, andLampetra fluviatilis, to measure changes in the amplitudes of calcium current induced by GABA and its specific antagonists and agonists. The experiments showed that GABA (4 mM) reduced the peak amplitude of the calcium current by 28.5±4.9%, with subsequent recovery to 96.2±9.2% of control (n=45). The GABAB agonist baclofen had similar effects. The GABAA agonists glycine and taurine had no effect on the Ca2+ current. The inhibitory effect of GABA was blocked by 2-hydroxysaclofen (a GABAB antagonist), but persisted in the presence of bicuculline (a GABAA antagonist). These results are evidence that the membranes of dorsal sensory cells contain GABAB receptors, which significantly increases our under-standing of the mechanisms of presynaptic inhibition in the spinal cords of the cyclostomata.

Comments

Neuroscience and Behavioral Physiology, Vol. 29, No. 1 (January/February 1999): 67-77. DOI.