Developmental increase in D-1-like dopamine receptor-mediated inhibition of glutamatergic transmission through P/Q-type channel regulation in the basal forebrain of rats

作者：Momiyama Toshihiko^*

来源：European Journal of Neuroscience, 2010, 32(4): 579-590.

DOI：10.1111/j.1460-9568.2010.07306.x

• D-1-like dopamine receptors
• developmental increase
• P
• Q-type calcium channels

Whole-cell patch-clamp recordings of non-N-methyl-d-aspartate glutamatergic excitatory postsynaptic currents (EPSCs) were carried out from cholinergic neurons in slices of basal forebrain (BF) of developing rats aged 21-42 postnatal days to elucidate postnatal developmental change in Ca2+ channel subtypes involved in the transmission as well as that in dopamine D-1-like receptor-mediated presynaptic inhibition. The amplitude of EPSCs was inhibited by bath application of omega-conotoxin GVIA (omega-CgTX; 3 mu m) or omega-agatoxin-TK (omega-Aga-TK; 200 nm) throughout the age range examined, suggesting that multiple types of Ca2+ channel are involved in the transmission. The EPSC fraction reduced by omega-CgTX decreased with age, whereas that reduced by omega-Aga-TK increased. Inhibition of the EPSCs by a D-1-like receptor agonist, SKF 81297 (SKF; 30 mu m) increased with age in parallel with the increase in omega-Aga-TK-induced inhibition. An activator of the adenylyl cyclase (AC) pathway, forskolin (FK; 10 mu m) inhibited the EPSCs, and FK-induced inhibition also increased with age in parallel with the increase in SKF-induced inhibition. Throughout the age range examined, SKF showed no further inhibitory effect on the EPSCs after omega-Aga-TK- or FK-induced effect had reached steady-state. These findings suggest that D-1-like receptor-mediated presynaptic inhibition of glutamate release onto cholinergic BF neurons increases with age, and that the change is coupled with a developmental increase in the contribution of P/Q-type Ca2+ channels as well as a developmental increase in AC pathway contribution.

• 出版日期2010-8