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Experience‐dependent regulation of functional maps and synaptic protein expression in the cat visual cortex
Author(s) -
Jaffer Sajjida,
Vorobyov Vasily,
Kind Peter C.,
Sengpiel Frank
Publication year - 2012
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2012.08044.x
Subject(s) - visual cortex , monocular deprivation , neuroscience , ampa receptor , inhibitory postsynaptic potential , excitatory postsynaptic potential , biology , postsynaptic potential , glutamate receptor , synaptic plasticity , postsynaptic density , sensory system , nmda receptor , neuroplasticity , neurotransmission , sensory deprivation , receptor , medicine , psychology , ocular dominance , biochemistry
Although the basis of our knowledge of experience‐dependent plasticity comes from studies on carnivores and primates, studies examining the physiological and molecular mechanisms that underlie development and plasticity have increasingly employed mice. We have used several common rearing paradigms, such as dark‐rearing and monocular deprivation (MD), to examine the timing of the physiological and molecular changes to altered experience in the cat primary visual cortex. Dark‐rearing from birth or for 1 week starting at 4 weeks of age produced a similar reduction in the amplitude of responses measured through intrinsic signal imaging and a reduction in orientation selectivity. One week of visual experience following dark‐rearing until 4 weeks of age yielded normal responses in both amplitude and orientation selectivity. The depression of deprived‐eye responses was similar in magnitude after 2 and 7 days of MD. In contrast, non‐deprived‐eye responses almost doubled in magnitude after 7 days compared with 2 days of MD. These changes in the functional properties of primary visual cortex neurons were mirrored by specific changes in synaptic protein expression. Changes in proteins such as the NR2A and NR2B subunits of the N ‐methyl‐D‐aspartate receptor, postsynaptic density protein 95, alpha‐CA 2+ /calmodulin‐dependent protein kinase II (αCaMKII), and GABA A α1a indicated that the levels of sensory activity regulated mechanisms associated with both excitatory (NR2A and NR2B) and inhibitory (GABA A α1a) transmission so as to maintain response homeostasis. Additionally, we found that MD regulated the AMPA receptor glutamate (GluR1) subunit as well as signalling molecules (αCaMKII and synaptic Ras GTPase activating protein, SynGAP) downstream of N ‐methyl‐D‐aspartate receptors. Proteins in a common signalling pathway appeared to have similar developmental expression profiles that were broadly similar between cats and rodents.