title: Impaired development and competitive refinement of the cortical frequency map in tumor necrosis factor-α-deficient mice.
abstract: Early experience shapes sensory representations in a critical period of heightened plasticity. This adaptive process is thought to involve both Hebbian and homeostatic synaptic plasticity. Although Hebbian plasticity has been investigated as a mechanism for cortical map reorganization, less is known about the contribution of homeostatic plasticity. We investigated the role of homeostatic synaptic plasticity in the development and refinement of frequency representations in the primary auditory cortex using the tumor necrosis factor-α (TNF-α) knockout (KO), a mutant mouse with impaired homeostatic but normal Hebbian plasticity. Our results indicate that these mice develop weaker tonal responses and incomplete frequency representations. Rearing in a single-frequency revealed a normal expansion of cortical representations in KO mice. However, TNF-α KOs lacked homeostatic adjustments of cortical responses following exposure to multiple frequencies. Specifically, while this sensory over-stimulation resulted in competitive refinement of frequency tuning in wild-type controls, it broadened frequency tuning in TNF-α KOs. Our results suggest that homeostatic plasticity plays an important role in gain control and competitive interaction in sensory cortical development.
authors: Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA.
authors: Sungchil
authors: S
authors: Yang
authors: Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA.
authors: Li S
authors: LS
authors: Zhang
authors: Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA.
authors: Robert
authors: R
authors: Gibboni
authors: Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA.
authors: Benjamin
authors: B
authors: Weiner
authors: Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA.
authors: Shaowen
authors: S
authors: Bao
mesh_terms: D000161:Acoustic Stimulation; D000367:Age Factors; D000465:Algorithms; D000704:Analysis of Variance; D000818:Animals; D001303:Auditory Cortex / Q000254:growth & development / Q000473:pathology / Q000503:physiopathology; D001308:Auditory Perceptual Disorders / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D001931:Brain Mapping; D003423:Critical Period, Psychological; D004195:Disease Models, Animal; D004777:Environment; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009473:Neuronal Plasticity / Q000235:genetics* / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000172:deficiency* / Q000235:genetics
chemical_list: D014409:Tumor Necrosis Factor-alpha
keywords: auditory cortex; development; homeostatic plasticity; plasticity; tumor necrosis factor