Anticonvulsants and anxiolytics: Benzodiazepines

Benzodiazepines are a class of medications that act as a central nervous system depressant.  They have a wide variety of uses including anxiolytic effects, or to relieve anxiety; as anticonvulsants, or to manage seizure disorders; as a hypnotic for insomnia; as an anesthetic; and to treat withdrawal syndromes. They act by enhancing the main inhibitory neurotransmitter gamma-aminobutyric acid, or GABA, by binding to its receptor.  

It’s pretty well-established that your brain’s really important. It controls your feelings, your movements, your sleep, your memory… It controls everything, whether you’re aware of it or not. The cells that make up our brain are called neurons. Neurons communicate with each other through neurotransmitters. When one neuron is stimulated, it’ll release excitatory neurotransmitters like glutamate which bind to receptors on the next neuron. This causes the next neuron to depolarize and release its own excitatory neurotransmitters, propagating the signal throughout the brain.  

Now, we also have inhibitory neurons that will shut down this chain of events. These neurons release the main inhibitory neurotransmitter gamma-aminobutyric acid, or GABA, which binds to GABA receptors on other neurons. These receptors are large, multi unit complexes that form ligand-gated ion channels that open up to let Cl- ions into the cell. The influx of negatively charged ions causes hyperpolarization, where the cell’s membrane potential becomes more negative, which means it’s much more difficult for it to depolarize and fire off an action potential, meaning it’s less responsive to stimuli.  

Alright, now there are cases where neurons in the brain start sending out more excitatory signals than normal. This can occur due to either too much excitation by the excitatory neurotransmitters, or too little inhibition by the inhibitory neurotransmitters like GABA. Excessive excitatory signals can cause psychiatric disorders like anxiety, and neurological disorders like seizures and epilepsy.