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

✍ Scribed by Waleed B. Alshuaib; Mini V. Mathew

• Book ID: 101245587
• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 137 KB
• Volume: 52
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/(sici)1097-4547(19980601)52:5<521::aid-jnr4>3.0.co;2-e

✦ Synopsis

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'' Drosophila neurons 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-cAMPtreated), and 3) dunce neurons. Delayed-rectifier potassium current was greater in both dunce neurons 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.