Numerous antiepileptic medications, such phenytoin, have been designed to block voltage-gated sodium channels (VGSC) in neuronal membrane. In addition, multiple toxins and pharmacological modulators work by attaching to various biophysical states of the VGSC to cause their effects. Depending on how modulatory agents act, some VGSC states are stabilized or destabilized, altering the channel's biophysical properties. The first anticonvulsant to successfully treat epileptic disorders without causing undesirable side effects such as brain drowsiness was phenytoin.
Phenytoin has been indicated to block high-frequency neuronal activity potentials from the inner vestibule of the pore, as demonstrated by electrophysiological research and site-directed mutation.
Frequency and voltage both affect phenytoin binding.
There are theories that phenytoin interferes with the late sodium current that sustains depolarizations in epilepsy by blocking non-inactivated channels.
The use of CRISPR/Cas9 avoids the need for protein engineering to develop a site-specific nuclease against a specific DNA target sequence, requiring only the synthesis of a new piece of RNA. This dramatically simplifies and greatly reduces the time needed for gene editing design and implementation.
Question:What is one difference between the theory of continental drift and the one theory of plate tectonics
Answer/Explanation: Continental drift is the hypothesis that states that the continents once formed a single landmass(Pangaea) broke up and drifted to their present locations.Sea-floor spreading the process by which new oceanic lithosphere(sea floor) forms as magma rises to Earth's surface and solidifies at a mid-ocean ridge.
