D1/D5 agonists - are they psychoactive?

[Matt the Raver]

Dopamine receptor are classified into 2 groups. D1 which bind to Gs and D2 which bind to Gi.
This would suggest that D1 and D2 type receptors have differing effects.
A quick browse of google scholar pulled up this:
Journal of Neuroscience, Vol 16, 1591-1604
I'm aware that D1 and D2 receptor activation are important for cocaine seeking behaviour,
Eur J Neurosci. 2006 Jan;23(1):219-28
But as these two receptors are also regulated in very different ways, which would make the effects of a D1/D2 agonist such as apomorphine somewhat 'messy'.
Baring this in mind how do the behavioural effects or psychoactive properties of D1/D5 ligands differ from those of D2 ligands?

 

[Matt the Raver]

Oh, I also found this, which kind of underlines the effect of D1 receptors in learn behaviour:

Neurosci Lett. 2006 Jul 10;402(1-2):46-50
Dopaminergic D(1) receptor agonist SKF 38393 induces GAP-43 expression and long-term potentiation in hippocampus in vivo

 

[Dr.Heckyll]

Here is something interesting:

Eur J Pharmacol. 1998 Feb 19;343(2-3):111-8.

Place conditioning with the dopamine D1-like receptor agonist SKF 82958 but not SKF 81297 or SKF 77434.Abrahams BS, Rutherford JD, Mallet PE, Beninger RJ.
Department of Psychology, Queen's University, Kingston, Ont., Canada.

While self-administration and place conditioning studies have shown that dopamine D2-like receptor agonists produce reward-related learning, the effects of dopamine D1-like receptor agonists remain equivocal. The present study tested three dopamine D1-like receptor agonists for their ability to induce a place preference. Like control rats treated with amphetamine (2.0 mg/kg i.p.), rats treated with SKF 82958 (+/- -6-chloro-7,8-dihydroxy-3-allyl-1-phenyl-2,3,4,5-tetrahydro-1-phenyl-1H- 3-benzazepine hydrobromide; 0.05 but not 0.01, 0.025, 0.075, or 0.10 mg/kg s.c. and/or i.p.) during conditioning showed a significant increase in the amount of time spent on the drug-paired side during the drug free test. Neither SKF 81297 (+/- -6-chloro-7,8-dihydroxy-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrobromide; 0.25, 0.50, 1.0, 2.0, and 4.0 mg/kg i.p.) nor SKF 77434 (+/- -7,8-dihydroxy-3-allyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride; 0.20, 1.0, 5.0, and 10.0 mg/kg i.p.) produced place conditioning. Significant increases in locomotion were seen at some doses of all drugs. Results show for the first time that systemic administration of a dopamine D1-like receptor agonist produces a place preference and are consistent with previous findings showing that dopamine D1-like receptor activation produces reward-related learning

 

[Matt the Raver]

I've just read the abstract that you've posted. I think that also confirms that D1 type receptors are important in spatial conditioning and possibly fits in with D1 mediated hippocampal LTP.
A paper that looks at the behavioural effects of D1 agonist AND a D2 antagonist or vice versa would be nice.
Have any D1 agonists been taken recreationally? I'ld predect a typically speedy effect, but it'ld be interesting to know if there are any differences.