Sleep-dependent plasticity requires cortical activity.
Recent findings in humans and animals suggest that sleep promotes synaptic plasticity, but the underlying mechanisms have not been identified. We have demonstrated recently an important role for sleep in ocular dominance (OD) plasticity, a classic form of in vivo cortical remodeling triggered by monocular deprivation (MD) during a critical period of development. The mechanisms responsible for the effects of sleep on OD plasticity are unknown but may depend on neuronal activity in the sleeping brain. We investigated the role of cortical activity in sleep-dependent plasticity by reversibly inactivating the sleeping visual cortex (V1) after a period of MD. Critical period cats were bilaterally implanted with cannulas in V1 and standard EEG/EMG electrodes for polysomnographic recording. After a period of MD, visual cortices were infused with the sodium channel blocker lidocaine in vehicle or vehicle only during sleep. A third group of cats served as sham controls and were infused with lidocaine outside of V1 (into the CSF). Both optical imaging of intrinsic cortical signals and microelectrode recordings showed that OD plasticity was significantly reduced in cats whose visual cortices were reversibly silenced during sleep. These findings demonstrate that the mechanisms governing this form of sleep-dependent plasticity require cortical activity. They provide an important insight into how sleep modifies synaptic circuitry by narrowing the range of possible candidate mechanisms to those that are activity dependent.
Jha
Sushil K
SK
Department of Neuroscience, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6074, USA.
Jones
Brian E
BE
Coleman
Tammi
T
Steinmetz
Nick
N
Law
Chi-Tat
CT
Griffin
Gerald
G
Hawk
Josh
J
Dabbish
Nooreen
N
Kalatsky
Valery A
VA
Frank
Marcos G
MG
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000704:Analysis of Variance; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal; D001931:Brain Mapping; D002415:Cats; D003423:Critical Period, Psychological; D003952:Diagnostic Imaging / Q000379:methods; D023882:Dominance, Ocular; D004569:Electroencephalography / Q000379:methods; D004576:Electromyography / Q000379:methods; D007839:Functional Laterality / Q000502:physiology; D066298:In Vitro Techniques; D008012:Lidocaine / Q000494:pharmacology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D012683:Sensory Deprivation / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D014793:Visual Cortex / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D014795:Visual Pathways / Q000187:drug effects / Q000502:physiology
D000779:Anesthetics, Local; D008012:Lidocaine