Gonna resurrect a very old thread here but I was just about to make a thread myself about minocycline, and still might when I have a bit more time, but I also think this is a really fascinating compound!
What an absolutely pointless divergence this thread took, funny how just a few years ago some people had such difficulty with the idea that ketamine might not, in fact, be an entirely benign compound.
On topic, I actually also did a little looking around for ketamine and minocycline interactions because I am currently an abstinent ketamine fan (and also because I have been taking minocycline, 100mg/day, for just over a week or so - and plan to do so indefinitely, or until I experience side effects) and found quite a few interesting studies, similar to the one you posted, OP -
Acute treatment with ketamine and chronic treatment with minocycline exert antidepressant-like effects and antioxidant properties in rats subjected different stressful events
Protective Effect of Minocycline Against Ketamine-Induced Injury in Neural Stem Cell: Involvement of PI3K/Akt and Gsk-3 Beta Pathway
Also, this paper has some very interesting tidbits which I will quote -
Antibiotic minocycline suppressess the phMRI response to acute ketamine challenge
Conclusions
Ketamine’s response profile was similar to the pattern seen in healthy volunteers [5] and 2-DG metabolic maps in conscious rats [7]. Pre-treatment with minocycline produced widespread inhibition of ketamine-induced functional activation, indicating direct involvement of this drug in modulating glutamate neurotransmission. Minocycline represents a potential new target for preventative and therapeutic compounds in treating schizophrenia.
I haven't dug into the schizophrenia-as-an-inflammatory response stuff too much yet, there seems to be some controversy as far as I can gather, but regardless, whether it's a direct or indirect mechanism the possible glutamatergic activity of this strange antibiotic is pretty interesting.
There was a study in humans relating to the potential anti-depressant effects of ketamine and/or minocycline which was terminated, prior to this thread - but I think there is actually one ongoing that started just last year with a slightly revised framework, I found some information on it when I was reading about this stuff yesterday, will have another look for the link if anyone is interested.
As far as the schizophrenia as an inflammatory response thing, without digging into specifics too much as again, am a little short on time, there have apparently been very strong indications that Alzheimer's might be connected to a form of bacteria that usually starts out in the gums but in some people, migrates to the brain and in some people, again, induces or strongly contributes to the progression of Alzheimers. I've seen it theorised that a high proportion of schizophrenic cases with no obvious genetic link may in future be attributed to some as yet undiscovered bacterial mechanism... in which case the apparent psychiatric side effects (good or bad) of minocycline and perhaps other similar antibiotic agents start to make more sense, absent, or in conjunction with, some as yet unclear direct chemical effect on neurotransmitters.
Again without digging into links too much, I've seen studies attempting to assess the effects of minocycline administration on things such as nicotine craving, or the acute effects of GABA-ergics, I can't remember any conclusions, if there were any, but it points to a lot of interesting and currently not well understood but potentially beneficial stuff going on.
I actually knew about some of the interesting stuff about this substance before I started taking it, and I'm not taking it for the psychiatric effects, and I'm only a week in so it's totally possible I'm placeboing myself, I know how vulnerable we all are to that effect... but subjectively I have felt on some days there is some definite, perceptible and subtle stuff going on, as it relates to both my mindset and my usage of other fairly mild performance enhancers sometimes (ie, modafinil, phenibut, nicotine - the latter not a PED but just something I have used occasionally of recent and feel there may be some interaction with).
One final thing - report I found funny but useful if true:
Antibiotic [minocycline] May Prevent Men From Overtrusting Attractive Women
