Differential synaptic processing separates stationary from transient inputs to the auditory cortex.
Sound features are blended together en route to the central nervous system before being discriminated for further processing by the cortical synaptic network. The mechanisms underlying this synaptic processing, however, are largely unexplored. Intracortical processing of the auditory signal was investigated by simultaneously recording from pairs of connected principal neurons in layer II/III in slices from A1 auditory cortex. Physiological patterns of stimulation in the presynaptic cell revealed two populations of postsynaptic events that differed in mean amplitude, failure rate, kinetics and short-term plasticity. In contrast, transmission between layer II/III pyramidal neurons in barrel cortex were uniformly of large amplitude and high success (release) probability (Pr). These unique features of auditory cortical transmission may provide two distinct mechanisms for discerning and separating transient from stationary features of the auditory signal at an early stage of cortical processing.
Atzori
M
M
LCMN/NICHD/NIH, Rm 5A72, Bldg 49, Convent Drive, Bethesda, Maryland 20892-4495, USA.
Lei
S
S
Evans
D I
DI
Kanold
P O
PO
Phillips-Tansey
E
E
McIntyre
O
O
McBain
C J
CJ
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001303:Auditory Cortex / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D001306:Auditory Pathways / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D001307:Auditory Perception / Q000187:drug effects / Q000502:physiology*; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D008239:Lysine / Q000031:analogs & derivatives*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009415:Nerve Net / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors / Q000378:metabolism; D013003:Somatosensory Cortex / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D018691:Excitatory Amino Acid Antagonists; D018091:Receptors, AMPA; C013411:biocytin; D008239:Lysine; D002118:Calcium