If amphetamines make your brain produce more melatonin, how come it makes you so awake?

I read that melatonin is one of the chemicals that amphetamines makes your brain produce. I thought this makes you tired, so how come you feel so full of energy? Is it because the neurotransmitters responsible for the stimulant effects greatly outweigh the effects of melatonin?

2 Responses to “If amphetamines make your brain produce more melatonin, how come it makes you so awake?”

  1. champiampi Says:

    So i to am not familiar with amphetamine-induced-melatonin production, however i can offer somewhat of a mechanistic link between the 2. So if anything, the production of melatonin which may be induced by amphetamine is definitly an indirect method. Ampethamine is classically regarded as a dopamine, noradrenaline, and even to some lesser extent serotonin uptake inhibitor "reverser", basically it cases uptake proteins to actually release neurotransmitters stores from their respective cells. Well, all of those NT's share circuitry with the hypothalamus, meaning they comunicate in sequence and regulate each other. The hypothalamus is the main regulator of melatonin production within the pineal gland. So assuming over activation by dopamine (most likely) input to cells of the hypothalamus is excitatory, or maybe even inhibitory, which then either excites or relieves inhibition exerted by the hypothalamus onto the pineal gland.

    So thats possibly the link, it should be noted that production of this kind is a much longer process, maybe takes hours to days? and i am not familiar with melatonin biosynthesis so whether it is stored in some sort of granule or vessicle, and released upon a different mechanism? It should be noted though that melatonin is not the only sleep factor, and may serve other regulatory roles that are not well understook as of yet?

  2. emily b Says:

    Never heard this, but here is a possible explaination I can think of-

    When cells recieve chemical signals from other cells, they are recieved on endplates that either upregulate (increase the likelihood of firing an AP) or downregulate (decrease the likelihood of the cell firing an AP) the cell.

    If the melatonin that the meth is increasing is at "docks" that are opposite of their primary dock when sober, then they may affect the neural mechanisms of sleep in a different way.

    But it may be your explanation.
    Any suggestions or slams for being wrong are welcome!