Table I.

Pharmacological tools, concentrations used and targets.

Compound	Abbreviation	Concentration	Target
N-Methyl-D-aspartic acid	NMDA	0.5 mM	NMDA receptors agonist
Cembratriene-4R-diol	4R	2 μM	α7 antagonist
Bicuculline methiodide	BMI	0.1 μM	GABAA antagonist
Dihydro-β-erythroidine	DHβE	1 μM	α4β2 receptors
Ly294002		10 μM	PI3-kinase inhibitor
PD98059		10 μM	MEK-1,2 inhibitor
Ro-31-8220		100 nM	selective PKC inhibitor
Vesamicol		50 μM	cholinergic vesicles
Methyllycaconitine	MLA	10 nM	α7 antagonist

The compounds used previously were tested alone for untoward effects on the size or shape of the PSs and on NMDA toxicity (Ferchmin et al., 2003; Ferchmin et al., 2005). BMI and vesamicol were used here for the first time and they were tested as described in results. BMI was routinely used at 0.1 μM; however, for the cumulative dose response curve (Figs. 2 and 3) it was used in the range of 0.01 to 1 μM. The following compounds were dissolved in DMSO: 4R, PD98059, Ro-31-8220, vesamicol, and Ly294002. At the concentrations used (<0.1% v/v), DMSO had no detectable effect. In every experiment, the slices in each condition were exposed to the same DMSO concentration for the same length of time.