Potassium current in Drosophila neurons is increased by either dunce mutation or cyclic AMP

• Published in: Journal of neuroscience research 1998-06, Vol.52 (5), p.521-529
• Main Authors: Alshuaib, Waleed B., Mathew, Mini V.
• Format: Article
• Language: English
• Subjects: Animals; Bucladesine - pharmacology; Cyclic AMP - physiology; Drosophila melanogaster; Drosophila melanogaster - embryology; Drosophila melanogaster - genetics; Drosophila melanogaster - physiology; Electric Conductivity; learning mutants; Memory, Short-Term - physiology; modulation; Mutation - physiology; Neurons - drug effects; Neurons - physiology; patch-clamp; Patch-Clamp Techniques; Potassium - physiology; Theophylline - pharmacology
• ISSN: 0360-4012; 1097-4547
• DOI: 10.1002/(SICI)1097-4547(19980601)52:5<521::AID-JNR4>3.0.CO;2-E

In the Drosophila mutant dunce, short‐term memory is deficient and intracellular cyclic adenosine monophosphate (cAMP) concentration is elevated. We examined the effect of increased cAMP concentration on the potassium current. The conventional whole‐cell technique was applied to cultured “giant” Drosophilaneurons derived from cell‐division arrested embryonic neuroblasts. Potassium membrane currents were measured from: 1) control wild‐type neurons, 2) wild‐type neurons with dibutyryl cAMP and theophylline in the culture media for 2 days (db‐cAMP‐treated), and 3) dunceneurons. Delayed‐rectifier potassium current was greater in both dunceneurons and db‐cAMP‐treated wild‐type neurons than in control wild‐type neurons. This result indicates that the neuronal potassium current is increased by the long‐term increase of cAMP. Conceivably, altered neuronal excitability in the dunce mutant could disrupt the processing of neural signals necessary for learning and memory. J. Neurosci. Res. 52:521–529, 1998. © 1998 Wiley‐Liss, Inc.