help! MAO breaking down neurotransmitters.Watch
this means if the MAO activity is low, less serotonin is broken down
more serotonin is found in the synaptic cleft
there's more serotonin activity
and because its an inhibitory neurotransmitter, there's less signal transmission
in a level psych, we learn that less signal transmission is good for decreasing aggression and impulsive behaviour
(ure more in control with controlled neuron firing) so why is it that the low MAO activity causes more aggression rather than less?!!
is it that less MAO activity indicates there's not much serotonin to breakdown anyway?
please help! the psych study forum is dead
1. Serotonin (actually now called 5-HT = 5-hydroxytryptamine) is NOT the only amine normally broken down by MAO. Others include dopamine and noradrenaline. Noradrenaline [NA] is a principally excitatory neurotransmitter, so if the level of NA rises due to reduced levels of MAO, this tends to increase activity in general, but may cause excitement and/or aggression more specifically.
2. The action of 5-HT on its receptors is very variable depending on the type of receptor; there are more than one type of 5-HT receptors, namely 5-HT1, 5-HT2a, 5-HT2b, etc [with the 1, 2a and 2b, respectively, written as subscripts]. This also introduces various types of psychological effects of changing levels of MAO.
In fact, MAOIs (MAO inhibitors) were used as antidepressants in the past, since as you probably know, the levels of monoamines in the brain have a role to play in maintaining mood [these drugs can also interact with certain foods like Chianti wine, cheese and avocado to increase blood pressure greatly (due to increased sympathetic input to the heart), and can lead to a stroke, so their use is very restricted].
M (clinical pharmacologist)