From my experience, the responses arent that big so I gonna post nevertheless as a kind of a blog with questions and possible ways to takle this.
Again a clue that points out the negative (and possible longterm effects) of cannabis:
The link between dopamine function and apathy in cannabis users: an [18F]-DOPA PET imaging study
Cannabis is the most widely used illicit drug in the world, and regular use has been associated with reduced motivation, i.e. apathy. Regular long-term cannabis use has been associated with reduced dopamine synthesis capacity. The mesolimbic dopaminergic system mediates the processing of incentive stimuli by modifying their motivational value, which in turn is modulated by endocannabinoid signalling. Thus, it has been proposed that dopaminergic dysfunction underlies the apathy associated with chronic cannabis use.
http://link.springer...0213-014-3523-4
Heres one of the underlying mechanisms:
Cannabinoid Action Depends on Phosphorylation of Dopamine- and cAMP-Regulated Phosphoprotein of 32 kDa at the Protein Kinase A Site in Striatal Projection Neurons
Herbal cannabis, smoked in the form of marihuana or hashish, is the most common illicit drug consumed in the Western world. In the brain, cannabinoids interact with neuronal CB1 receptors, thereby producing a marked reduction of motor activity. Here, we report that the motor depressant effect produced by the cannabinoid receptor agonist (-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]trans-4-(3-hydroxypropyl)cyclohexanol (CP55,940) is attenuated by genetic inactivation of the dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32),
http://www.jneurosci...pe2=tf_ipsecsha
--> reduced motor activity is afaik either caused by reduced dopamine D2 activation and/or by reduced dopamine production and is related to the Striatum which is also implicated into mood, affect and motivation and perhaps cognition( since theres a crosstalk between e.g. the PFC)
- I´ve read allready a bit into DARPP-32 because its also impicated into the effects of cocaine ( a desperate attempt to improve my situation 2 years ago..)
See my post#2 in my:
Cocaine News + reversal thread
http://www.longecity...ad/#entry653765
This looks also interresting:
Concomitant activation of adenylyl cyclase suppresses the opposite influences of CB(1) cannabinoid receptor agonists on tyrosine hydroxylase expression.
http://www.ncbi.nlm....pubmed/18992715
--> The reason might be:
Reciprocal influences of CB1 cannabinoid receptor agonists on ERK and JNK signalling in N1E-115 cells.
Using a luciferase reporter assay, we observed that the MAP/ERK kinase (MEK1/2) inhibitors, U0126 (5 μM) and PD98059 (25 μM) reduced basal activity of the TH gene promoter while SP600125 (10 μM), an inhibitor of JNK, significantly increased this basal activity.
http://www.sciencedi...014579308008399
This author (Bosier B) has done further seemingly, helpful investigations into this topic. Admittely, his statement seem to me sometimes contradictory e.g. in regards of TH expression.
Anyway, Forskolin seems to further decrease the TH expression:
Concomitant activation of adenylyl cyclase suppresses the opposite influences of CB(1) cannabinoid receptor agonists on tyrosine hydroxylase expression.
Therefore, we studied the consequences of manipulating adenylyl cyclase activity with forskolin on the regulation of TH gene transcription in neuroblastoma cells (N1E-115). Reporter gene experiments performed with the luciferase sequence cloned under the control of modified fragments of the TH gene promoter revealed that the AP-1 consensus sequence is essential for cannabinoid-mediated regulation of TH expression. Consistently, inhibition of PKC totally blocked the responses mediated by both HU 210 and CP 55,940. In addition, forskolin which boosts adenylyl cyclase activity remarkably modified the responses to the cannabinoid agonists. Thus, in these conditions, both agonists efficiently reduced TH gene promoter activity, a response requiring functional PKA/CRE-dependent signallings. Finally, the modulations of the promoter were inhibited in pertussis toxin treated cells, suggesting that responses to both agonists are mediated through G(i/o)-dependent mechanisms. Emphasising on the importance of functional selectivity at GPCRs, these data demonstrate that the concomitant activation of adenylyl cyclase by forskolin strongly influences the biochemical responses triggered by distinct cannabinoid agonists.
http://www.ncbi.nlm....pubmed/18992715
As expected for cannabinoid agonists, the exposure to either Δ(9)-THC, HU 210 or CP 55,940 induced both catalepsy and hypolocomotion. Supporting a possible long-lasting control on dopaminergic activity..
- so here comes the ? -
we noticed a significant HU 210-mediated increase in TH expression in the striatum that was concomitant with an increase in striatal dopamine content. Surprisingly, while a similar trend was reported with Δ(9)-THC, CP 55,940 completely failed to modulate TH expression or dopamine content. Nevertheless, the access of CP 55,940 to brain structures was validated by determinations of drug concentrations in the tissue and by ex vivo binding experiments. Furthermore, confirming the central activity of CP 55,940, the analysis of dopamine metabolites revealed a reduction in striatal DOPAC concentrations. Consistent with the involvement of the CB(1) cannabinoid receptor in these different responses, both HU 210- and CP 55,940-mediated effects were prevented by SR 141716A. Therefore, the present data suggest that both HU 210 and CP 55,940 cause a delayed/persistent regulation of the dopamine neurotransmission system.
SR 141716A = a CB1 antagonist prevents the effects on TH expression
EDIT :
Found a full-text of
Differential modulations of striatal tyrosine hydroxylase and dopamine metabolism by cannabinoid agonists as evidence for functional selectivity in vivo.
http://www.uclouvain...acology2012.pdf
Its beeing confirmed that adenyl cyclase is responsible for the decrease of TH. Interrestingly, HU-210 shares similair effects to THC but THC seem to not affect TH that much.
I´m currently thinkng of HU-210 sour4ces but have to look more into it.
TH-expression might be good on the first look but its also implicated into Alzheimer and PArkinson so a balanced increas would be wise (if possible)
Edited by Flex, 26 May 2015 - 10:32 PM.