Flip and flop: a cell-specific functional switch in glutamate-operated channels of the CNS

Science. 1990 Sep 28;249(4976):1580-5. doi: 10.1126/science.1699275.


In the central nervous system (CNS), the principal mediators of fast synaptic excitatory neurotransmission are L-glutamate-gated ion channels that are responsive to the glutamate agonist alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA). In each member of a family of four abundant AMPA receptors, a small segment preceding the predicted fourth transmembrane region has been shown to exist in two versions with different amino acid sequences. These modules, designated "flip" and "flop," are encoded by adjacent exons of the receptor genes and impart different pharmacological and kinetic properties on currents evoked by L-glutamate or AMPA, but not those evoked by kainate. For each receptor, the alternatively spliced messenger RNAs show distinct expression patterns in rat brain, particularly in the CA1 and CA3 fields of the hippocampus. These results identify a switch in the molecular and functional properties of glutamate receptors operated by alternative splicing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Brain / metabolism*
  • DNA / genetics
  • Exons
  • Genomic Library
  • Glutamates / metabolism*
  • Glutamates / pharmacology
  • Ibotenic Acid / analogs & derivatives*
  • Ibotenic Acid / metabolism
  • Ibotenic Acid / pharmacology
  • Ion Channels / physiology*
  • Kinetics
  • Molecular Sequence Data
  • Oligonucleotide Probes
  • Organ Specificity
  • RNA Splicing*
  • RNA, Messenger / genetics*
  • Rats
  • Receptors, AMPA
  • Receptors, Glutamate
  • Receptors, Neurotransmitter / drug effects
  • Receptors, Neurotransmitter / genetics*
  • Receptors, Neurotransmitter / physiology
  • Recombinant Proteins / metabolism
  • alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid


  • Glutamates
  • Ion Channels
  • Oligonucleotide Probes
  • RNA, Messenger
  • Receptors, AMPA
  • Receptors, Glutamate
  • Receptors, Neurotransmitter
  • Recombinant Proteins
  • Ibotenic Acid
  • alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
  • DNA

Associated data

  • GENBANK/M36418
  • GENBANK/M36419
  • GENBANK/M36420
  • GENBANK/M36421
  • GENBANK/M38060
  • GENBANK/M38061
  • GENBANK/M38062
  • GENBANK/M38063