Epilepsy Word Scramble
|
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Question | Answer |
Thalamocortical circuit - disruption causes epilepsy (related to GABAb) | oscillations between thalamus and cortex determine the level of consciousness and perception: Burst mode (sleep, low-f, synchronised); Tonic mode (awake, high-f, asynchronous) |
Corticothalamic network and spike-wave generation 1 (EEG) | 1)the thalamocortical relay neurons receive afferent sensory excitatory input and subsequently activate the cortical pyramidal neurons and adjacent GABA interneurons |
Corticothalamic network and spike-wave generation 2 | 2)this is further spread to adjacent cortical neurons, generating a burst of activity and propagate back to the thalamus, acitivating nucleus reticularis thalami GABAergic neurons and local thalamic GABAerigc interneurons |
Corticothalamic network and spike-wave generation 3 | 3)The hyperpolerising effects may activate low-threshold ch., generating slow waves which will then trigger the activation of the circuit |
Systems involved | 1)Glutamatergic transmission 2)GABAerigc transmission 3)Voltage-gated channels (Na, Ca and KCNQ) |
Causes of epilepsy | Dysfunction to ion channel and receptor trafficking Mutation of transmembrane channels (V and L-gated) are the underlying cause of many forms of human epilepsy Loss of function in inhibitory neurotransmission or gain """, leading to disinhibition |
Definition of epilepsy | long-term neurological disorder characterised by epileptic seizures |
Neuronal excitability | depends on the movement of ions ion channels are heterooligmeric proteins specially adapted to regulate trans membrane ion fluxes that respond to ligand binding/ voltage changes |
Ca channels | membrane excitability due to voltage-activated Ca currents P/Q type plays a dominant role in synaptic transmission *T currents can sustain rhythmic burst of firing in thalamocortical relay neurons, essential for synchronisation during absense seizures |
Absence seizure | Large part of T-C circuit becomes synchronised due to prolonged GABAB-R activation |
Mutation of GABAa-R have been linked to three types of idiopathic epilepsies | 1)childhood absence epilepsy 2)abnormal dominant epilepsy with febrile seizures plus (ADEFS+) 3)juvenile myoclonic epilepsy |
Mutation in GABAa-R subunit gens have been associated with idiopathic generalised epilepsy syndromes | mutation include mis-sense, nonsense, and frameshift mutations in coding or non-coding genes |
Mis-sense | in general, cause trafficking and/or gating defects |
Premature translation-termination codon (PTC) | generated by nonsense, deletion or frameshift mutation produce truncated protein, often causes server disease than mis-sense |
Nonsense mediated decay | PTC-generating mutant subunits are subject to NMD |
ERAD | mutants that escape NMD often are trafficking, misfold and misrouted - endoplasmic reticulum associated degradation |
Gamma2 Q351X | Mis-sense, produce no functional Cl ch. due to intracellular retention |
Gamma2 K289M | Mis-sense at linker of M2 and M3, tonic-chronic and febrile seizures, causes significant reduction in the amplitude of GABAa current and shortening of the receptor open time |
Delta E177A | Mis-sense, activated of the peak current under saturated doses of GABA without changing the binding affinity, decreased open time and reduced cellular expression |
Anticonvulsants | Carbamazepine (Na Ca) Valproate (Ca and GABA-T) Lamotrigine (Glu) Vigabatrin (GABA-T) Benzodiazepines and Barbiturates |
Created by:
JonLai
Popular Medical sets