TrkB Activation during a Critical Period Mimics the Protective Effects of Early Visual Experience on Perception and the Stability of Receptive Fields in Adult Superior Colliculus
| Autor: | Noura Machhour, So Yeon Kim, Timothy S. Balmer, Sarah L. Pallas, David B. Mudd |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Male Aging Superior Colliculi genetic structures Tropomyosin receptor kinase B Biology Visual system Ocular dominance 03 medical and health sciences Mice 0302 clinical medicine Lateral inhibition Cricetinae medicine Animals Sensory deprivation Phosphorylation Maze Learning Research Articles Membrane Glycoproteins Mesocricetus Perineuronal net General Neuroscience Superior colliculus Critical Period Psychological Azepines Fear Darkness Protein-Tyrosine Kinases Flavones Mice Inbred C57BL 030104 developmental biology Visual cortex medicine.anatomical_structure nervous system Receptive field Benzamides biology.protein Visual Perception Female Sensory Deprivation Neuroscience Protein Processing Post-Translational Parvalbumin 030217 neurology & neurosurgery Photic Stimulation |
| Zdroj: | The Journal of neuroscience : the official journal of the Society for Neuroscience. 39(23) |
| ISSN: | 1529-2401 |
| Popis: | During a critical period in postnatal development, spontaneous and evoked retinal activity shape nascent visual pathways in an adaptive fashion. Visual experience increases transcription of the neurotrophin BDNF, activating the BDNF receptor TrkB, which promotes maturation of parvalbumin (PV) positive inhibitory interneurons, a process thought to open a critical period for ocular dominance plasticity in visual cortex. Development of perineuronal nets around PV neurons limits plasticity, ending the critical period and restricting adult plasticity. Another form of critical period plasticity is receptive field (RF) refinement. Spontaneous activity alone is sufficient for spatial refinement of visual receptive fields in superior colliculus (SC) and visual cortex (V1), but visual experience during an early critical period is necessary to maintain inhibitory synapses and stabilize RFs in adulthood (Carrasco et al. 2005, 2011; Carrasco & Pallas 2006; Balmer & Pallas 2015a). We report here that deprivation-induced RF enlargement in adulthood has a behavioral consequence; it impairs fear responses to looming objects in mice and hamsters. The mechanism through which early experience protects RFs from deprivation-induced loss of inhibition in adulthood is unknown. Given that the loss of RF refinement in SC does not occur until adulthood, and that inhibitory PV neurons and perineuronal nets are rare in SC, we asked whether or not BDNF-TrkB signaling was involved. We find that early TrkB activation is necessary and sufficient to maintain visual RF refinement in adulthood, suggesting a common signaling pathway for maturation of inhibition across neuronal subtypes and locations within the visual pathway. Significance Statement Receptive field refinement in superior colliculus (SC) differs from more commonly studied examples of critical period plasticity in visual pathways in that it does not require visual experience to occur; rather spontaneous activity is sufficient. Maintenance of refinement requires brief, early exposure to light to stabilize inhibition beyond puberty. This type of inhibitory plasticity must not depend on parvalbumin (PV)-containing GABAergic interneurons or on the formation of perineuronal nets, because these are very uncommon in SC. Nonetheless, we find that TrkB activation during a critical period can substitute for visual experience in maintaining receptive field refinement into adulthood, and that this maintenance is beneficial to visual survival behaviors. Thus, multiple types of plasticity converge on the same neurotrophin-dependent signaling cascade. |
| Databáze: | OpenAIRE |
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