Parallel processing of sensory input by bursts and isolated spikes.
Burst firing is commonly observed in many sensory systems and is proposed to transmit information reliably. Although a number of biophysical burst mechanisms have been identified, the relationship between burst dynamics and information transfer is uncertain. Electrosensory pyramidal cells have a well defined backpropagation-dependent burst mechanism. We used in vivo, in vitro, and modeling approaches to investigate pyramidal cell responses to mimics of behaviorally relevant sensory input. We found that within a given spike train, bursts are biased toward low-frequency events while isolated spikes simultaneously code for the entire frequency range. We also demonstrated that burst dynamics are essential for optimal feature detection but are not required for stimulus estimation. We conclude that burst and spike dynamics can segregate a single spike train into two parallel and complementary streams of information transfer.
Oswald
Anne-Marie M
AM
Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1G 2K4, Canada. ammoswald@yahoo.com
Chacron
Maurice J
MJ
Doiron
Brent
B
Bastian
Joseph
J
Maler
Leonard
L
D000200:Action Potentials / Q000502:physiology*; D000344:Afferent Pathways / Q000502:physiology*; D000818:Animals; D003198:Computer Simulation; D004558:Electric Stimulation / Q000379:methods; D023702:Gymnotiformes / Q000502:physiology*; D008959:Models, Neurological; D016011:Normal Distribution; D017966:Pyramidal Cells / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted