Abstract

Delays in synaptic and neuronal development in the cortex are key hallmarks of fragile X syndrome, a prevalent neurodevelopmental disorder that causes intellectual disability and sensory deficits and is the most common known cause of autism. Previous studies have demonstrated that the normal progression of plasticity and synaptic refinement during the critical period is altered in the cortex of fragile X mice. Although the disruptions in excitatory synapses are well documented in fragile X, there is less known about inhibitory neurotransmission during the critical period. GABAergic transmission plays a crucial trophic role in cortical development through its early depolarizing action. At the end of cortical critical period, response properties of GABA transform into their mature hyperpolarizing type due to developmental changes in intracellular chloride homeostasis. We found that the timing of the switch from depolarizing to hyperpolarizing GABA is delayed in the cortex of fragile X mice and there is a concurrent alteration in the expression of the neuronal chloride cotransporter NKCC1 that promotes the accumulation of intracellular chloride. Disruption of the trophic effects of GABA during cortical development could contribute to the altered trajectory of synaptic maturation in fragile X syndrome.

Keywords

NeuroscienceFragile X syndromeNeurotransmissionExcitatory postsynaptic potentialGABAergicInhibitory postsynaptic potentialDepolarizationBiologyPeriod (music)Synaptic plasticityEndocrinologyReceptor

MeSH Terms

AnimalsBlottingWesternCritical PeriodPsychologicalDisease ModelsAnimalFragile X SyndromeMaleMiceMiceInbred C57BLMiceKnockoutNeurogenesisPatch-Clamp TechniquesReal-Time Polymerase Chain ReactionSolute Carrier Family 12Member 2Somatosensory Cortexgamma-Aminobutyric Acid

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Publication Info

Year
2014
Type
article
Volume
34
Issue
2
Pages
446-450
Citations
222
Access
Closed

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222
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12
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206
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Cite This

Qionger He, Toshihiro Nomura, Jian Xu et al. (2014). The Developmental Switch in GABA Polarity Is Delayed in Fragile X Mice. Journal of Neuroscience , 34 (2) , 446-450. https://doi.org/10.1523/jneurosci.4447-13.2014

Identifiers

DOI
10.1523/jneurosci.4447-13.2014
PMID
24403144
PMCID
PMC6608154

Data Quality

Data completeness: 86%