Laminar Specific Cortical Plasticity following Mouse Sensory Deprivation
Friday, September 14, 2018 — Poster Session V
- KA Sheth
- E Petrus
- S Dodd
- AP Koretsky
Sensory deprivation produces widespread cortical reorganization. Our lab has developed an animal model of unilateral sensory deprivation by cutting the infraorbital nerve (ION - whisker). Previous fMRI and slice electrophysiology studies detected dramatic changes in both the intact and deprived primary somatosensory barrel cortices (S1BCs). The intact S1BC has an increase in the strength and number of feed-forward synapses arriving from the thalamus to layer 4. The deprived S1BC is recruited to intact whisker stimulation, which is mediated by the corpus callosum. The goals of this project were 1) to determine if changes in fMRI signal and the increases in synaptic strength or number could be detected anatomically, and 2) if there was a behavioral phenotype associated with unilateral whisker denervation. Manganese-enhanced MRI (MEMRI), was used to enhance visualization of layer 4 in mouse S1BC, and the thickness of both intact and deprived sides were quantified in vivo. Preliminary data show a decreased layer thickness in deprived cortex compared to sham animals. Behavioral studies were conducted with an open field test with subsequent novel object placement to asses both pain/anxiety associated and exploratory behaviors. Preliminary data showed that ION cut mice spent significantly more time with their whisker cut side against the wall than sham mice, suggesting a guarding behavior for their injured side. Additionally, ION cut mice inspected a novel object more frequently using nose touches compared to sham mice. Our data demonstrates that layer-specific changes in S1BC may hold clues into the mechanisms underlying sensory deprivation induced plasticity.