Case study- Epilepsy-A 12-year-old boy develops convulsions..

Question of the day

A 12-year-old boy develops convulsions. After running an electroencephalogram (EEG), a neurologist determines that the child has epilepsy. He is started on Benzodiazepine, which promotes the activity of GABA . GABA is derived from the amino acid glutamate via which of the following biochemical reactions ?

A. Deamination

B. Decarboxylation

C. Hydroxylation

D. Iodination

E. Methylation

MOA of benzodiazepine

Figure- Benzodiazepines  bind to the gamma sub-unit of the GABA-A receptor. Their binding causes an allosteric (structural) modification of the receptor that results in an increase in GABA A receptor activity. Benzodiazepines do not substitute for GABA, which bind at the alpha sub-unit, but increase the frequency of channel opening events which leads to an increase in chloride ion conductance and inhibition of the action potential.

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3 Responses

  1. Perfect answers, Thank you for your comments.

  2. Javin Gogoi says:

    Answer- B- Decarboxylation.
    GABA is synthesised from Glutamate by decarboxylation reaction catalysed by the enzyme Glutamate decarboxylase in presence of PLP as coenzyme.
    GABA acts as an inhibitory neurotransmitter by opening up the Chloride channels in post-synaptic membrane.
    Decrease level of GABA or deficiency of vitamin pyridoxine (active form PLP) would cause convulsions.
    Drugs which can increase opening of Chloride channels are used in the cases of convulsions.

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