Defective GABAergic Neurotransmission and Pharmacological Rescue of Neuronal Hyperexcitability in the Amygdala in a Mouse Model of Fragile X Syndrome
| Autor: | Jose Luis Olmos-Serrano, Scott M. Paluszkiewicz, Joshua G. Corbin, Molly M. Huntsman, Brandon S. Martin, Walter E. Kaufmann |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Male
congenital hereditary and neonatal diseases and abnormalities Patch-Clamp Techniques Synaptic cleft In Vitro Techniques Neurotransmission Inhibitory postsynaptic potential Synaptic Transmission Amygdala Article gamma-Aminobutyric acid Fragile X Mental Retardation Protein Mice Interneurons medicine Animals Tonic (music) Evoked Potentials GABA Agonists gamma-Aminobutyric Acid Mice Knockout Neurons Glutamate Decarboxylase General Neuroscience Neural Inhibition Isoxazoles Disease Models Animal medicine.anatomical_structure Fragile X Syndrome GABAergic Psychology Neuroscience Gaboxadol medicine.drug |
| Zdroj: | Journal of Neuroscience. 30:9929-9938 |
| ISSN: | 1529-2401 0270-6474 |
| DOI: | 10.1523/jneurosci.1714-10.2010 |
| Popis: | Fragile X Syndrome (FXS) is a neurodevelopmental disorder characterized by variable cognitive impairment and behavioural disturbances such as exaggerated fear, anxiety and gaze avoidance. Consistent with this, findings from human brain imaging studies suggest dysfunction of the amygdala. Underlying alterations in amygdala synaptic function in the Fmr1 knockout (KO) mouse model of FXS, however, remain largely unexplored. Utilizing a combination of approaches, we uncover profound alterations in inhibitory neurotransmission in the amygdala of Fmr1 KO mice. We demonstrate a dramatic reduction in the frequency and amplitude of phasic inhibitory postsynaptic currents (IPSCs), tonic inhibitory currents, as well as in the number of inhibitory synapses in Fmr1 KO mice. Furthermore, we observe significant alterations in GABA availability, both intracellularly and at the synaptic cleft. Together, these findings identify abnormalities in basal and action potential-dependent inhibitory neurotransmission. Additionally, we reveal a significant neuronal hyperexcitability in principal neurons of the amygdala in Fmr1 KO mice, which is strikingly rescued by pharmacological augmentation of tonic inhibitory tone using the GABA agonist, gaboxadol (THIP). Thus, our study reveals relevant inhibitory synaptic abnormalities in the amygdala in the Fmr1 KO brain and supports the notion that pharmacological approaches targeting the GABAergic system may be a viable therapeutic approach toward correcting amygdala-based symptoms in FXS. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|