July 18 (Fri)
room 67, basement of Broad center.
we'll cover the following Nat Neuro paper. Since it is a dense paper, please read the paper to prepare for the discussion.
Behavior-dependent short-term assembly dynamics in
the medial prefrontal cortex
Shigeyoshi Fujisawa1, Asohan Amarasingham1, Matthew T Harrison2 & Gyo¨ rgy Buzsa´ ki1
Although short-term plasticity is believed to play a fundamental role in cortical computation, empirical evidence bearing on its
role during behavior is scarce. Here we looked for the signature of short-term plasticity in the ﬁne-timescale spiking relationships
of a simultaneously recorded population of physiologically identiﬁed pyramidal cells and interneurons, in the medial prefrontal
cortex of the rat, in a working memory task. On broader timescales, sequentially organized and transiently active neurons reliably
differentiated between different trajectories of the rat in the maze. On ﬁner timescales, putative monosynaptic interactions
reﬂected short-term plasticity in their dynamic and predictable modulation across various aspects of the task, beyond a
statistical accounting for the effect of the neurons' co-varying ﬁring rates. Seeking potential mechanisms for such effects,
we found evidence for both ﬁring pattern–dependent facilitation and depression, as well as for a supralinear effect of
presynaptic coincidence on the ﬁring of postsynaptic targets.