Plasticity of cortical networks during learning

PROJECT SUMMARY:
Plasticity occurs in the primary visual cortex (V1) in response to visual associative learning, where one
stimulus is paired with reward (CS+) and another is not (CS-). However, learning is not a unitary process, and
distinct stages of learning might drive contrasting plastic changes in V1. Indeed, previous work has found
dynamic changes in V1 pyramidal neuron activity and inputs at different times throughout learning. Experiments
separating distinct learning phases behaviorally are lacking, making it difficult to fully dissect V1 plasticity
changes throughout learning. To address this, we have designed a 3-phase associative learning task that
separates early, stimulus non-specific learning from late, stimulus-specific learning and reversal learning. We
will also manipulate stimulus value in two ways: devaluation and spout removal. Using this behavioral paradigm
along with 1- and 2-photon calcium imaging of the mouse dorsal cortex, we will test the following hypotheses: 1)
that visual associative learning differentially recruits V1 activity during distinct learning stages, 2) activity in V1 is
rapidly plastic in response to changes in stimulus value, 3) individual V1 neurons exhibit bidirectional plasticity
across learning, 4) visual associative learning changes cortico-cortical functional connectivity, and 5) V1 activity
is required to maintain these cortico-cortical functional connectivity changes. Our results will provide an
unprecedented level of insight into V1 plasticity throughout learning and stimulus value manipulation. We will,
for the first time, address how plasticity in V1 is mirrored across the dorsal cortex, or required for cortico-cortical
plasticity.

Grant Number: 3F30EY034380-03S1
NIH Institute/Center: NIH
Principal Investigator: Hannah Batchelor