Lecture 8: Brain and Behaviors
•Also known as sedative hypnotics.
•By definition it means that it causes the cortex to go into a more relaxed state.
•There are three major categorizes for depressants:
Can work in different ways. The primary way is through GABA.GABA
is the primary inhibitory amino acid transmitter. Barbiturates bind
together receptors. That is the primary mechanism of action. It lowers
brain excitability. Almost all of these are also synergistic with each
other. For drugs to be synergistic means that they have to work in very
similar mechanisms and that they can add to each other or they can
cancel each other out. By canceling each other out meaning canceling
out the withdrawal effects of each other. Synergistic means that they
are very similar in their mechanism of action. For example:
barbiturates and alcohol add other very quickly. And some people use
it to imply (more than adds it actually multiplies) the effect. Therefore
a lot of people die because they take barbiturates and alcohol together.
Because barbiturates are synergistic is becomes very lethal. Well most
of these will prevent the withdrawal effects of the other ones.
Whenever we put someone in the hospital for alcohol, we put them on
valium (is another depressant), so they can be behaviorally treated
first. However, taking a person off of alcohol cold turkey, would make
the brain go in hypertension, therefore increase the chances of getting
seizures. *Main point these are synergistic, meaning that they can
work to cancel the withdrawal affects of the two drugs or add to the
withdrawal effects of the two drugs. Barbiturates are prescribed
normally for sleep induction or to induce sleep. Typically they are used
most commonly in elderly individuals. Because as you go through
lifespan maturation, sleep wakeful cycles get disturbed in people as
they get older. Therefore they would have a lot of trouble sleeping.
Therefore, they tend to wake up a lot at night. And this is the most
common use for barbiturates, is to help the elderly sleep. So if there is
an abuse of this drug, it’s mostly done by elderly people. The problem
is that when people are barbiturates, people don’t go through REM
sleep, sleep involving rapid eye movements as well as dreaming.
Barbiturates, they do induce sleep however they reduce the amount of
time in REM sleep. Often the person is still tired or not quite right,