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Updated: Jul 31, 2026

Double-barreled and Concentric Microelectrodes for Measurement of Extracellular Ion Signals in Brain Tissue
Published on: September 5, 2015
Octopamine reduces potassium permeability of the glia that form the insect blood-brain barrier
Abstract:
Octopamine caused only a slight reduction in the potential across the perineurial glia of the cockroach, had no effect upon sodium-induced changes in potential, but did reduce potassium-induced changes (at 10(-7) M and above). The effect of 10(-7) M octopamine was accompanied by a rise in resistance, was mimicked by 10(-7) M synephrine and blocked by 10(-6) M phentolamine. Transperineurial potassium permeability was reduced by 10(-6) M octopamine. It is concluded that octopamine receptors mediate a reduction in potassium conductance of the basolateral membrane of these glia, and a reduction in the net potassium permeability of the barrier.
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