A "sample-and-hold" pulse-counting integrator as a mechanism for graded memory underlying sensorimotor adaptation.
The mechanisms behind the induction of cellular correlates of memory by sensory input and their contribution to meaningful behavioral changes are largely unknown. We previously reported a graded memory in the form of sensorimotor adaptation in the electromotor output of electric fish. Here we show that the mechanism for this adaptation is a synaptically induced long-lasting shift in intrinsic neuronal excitability. This mechanism rapidly integrates hundreds of spikes in a second, or gradually integrates the same number of spikes delivered over tens of minutes. Thus, this mechanism appears immune to frequency-dependent fluctuations in input and operates as a simple pulse counter over a wide range of time scales, enabling it to transduce graded sensory information into a graded memory and a corresponding change in the behavioral output. This adaptation is based on an NMDA receptor-mediated change in intrinsic excitability of the postsynaptic neurons involving the Ca2+-dependent activation of TRP channels.
Section of Neurobiology, The University of Texas at Austin, 1 University Station C0920, Austin, Texas 78712, USA.
Jörg
J
Oestreich
Nikolai C
NC
Dembrow
Andrew A
AA
George
Harold H
HH
Zakon
D000064:Acclimatization; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D000595:Amino Acid Sequence; D000818:Animals; D001522:Behavior, Animal; D001683:Biological Clocks / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004555:Electric Fish; D004557:Electric Organ / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005439:Flufenamic Acid / Q000494:pharmacology; D066298:In Vitro Techniques; D008526:Medulla Oblongata / Q000166:cytology; D008568:Memory / Q000502:physiology*; D008959:Models, Neurological; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D010812:Physical Stimulation / Q000379:methods; D010879:Piperazines / Q000494:pharmacology; D050053:TRPM Cation Channels / Q000037:antagonists & inhibitors / Q000378:metabolism; D020866:omega-Conotoxin GVIA / Q000494:pharmacology
D002121:Calcium Channel Blockers; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D010879:Piperazines; D050053:TRPM Cation Channels; D005439:Flufenamic Acid; D016202:N-Methylaspartate; D020866:omega-Conotoxin GVIA; C050592:3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid; D002118:Calcium