Release and uptake of catecholamines in the bed nucleus of the stria terminalis measured in the mouse brain slice.
The release and clearance of electrically evoked catecholamine (CA) in the ventral portion of the bed nucleus of the stria terminalis (BSTV) in mouse brain slices was evaluated with fast-scan cyclic voltammetry at carbon-fiber microelectrodes (CFME). Uptake in this region was observed to be markedly slower than in the caudate putamen (CPu). Clearance rates were reduced in the BSTV in both norepinephrine transporter knockout (NET KO) and dopamine transporter knockout (DAT KO) mice when compared to results in wild-type (WT) mice. However, uptake was faster in the BSTV in both the DAT and NET KO mice than in the CPu of DAT KO mice. This indicates that both transporters play a role in CA clearance in the BSTV. The transporters restrict extracellular CA to the general area of the BSTV, as revealed by the diminished signal as the CFME is moved sequentially further and further from the site where CA release is evoked. However, in slices from the DAT KOs and NET KOs, CA release could be observed outside of the BSTV region during such experiments. These results show that the low rate uptake in the BSTV facilitates extrasynaptic diffusion of catecholamine, but that uptake still regulates and limits the range of the transmitter to the region. Slower clearance from the extracellular fluid allows the released CA to act as a volume transmitter and diffuse to distant sites within the region to exert its neurochemical action.
Miles
Petrise Runnels
PR
Department of Chemistry and Neuroscience Center, University of North Carolina-Chapel Hill, North Carolina 27599-3290, USA.
Mundorf
Michelle L
ML
Wightman
R Mark
RM
D000469:Alkaline Phosphatase / Q000096:biosynthesis / Q000235:genetics; D000818:Animals; D001921:Brain / Q000378:metabolism; D002395:Catecholamines / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000172:deficiency / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins; D050484:Norepinephrine Plasma Membrane Transport Proteins; D012686:Septal Nuclei / Q000378:metabolism*; D027981:Symporters / Q000172:deficiency / Q000235:genetics
D002395:Catecholamines; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D050484:Norepinephrine Plasma Membrane Transport Proteins; C493228:Slc6a2 protein, mouse; C493215:Slc6a3 protein, mouse; D027981:Symporters; D000469:Alkaline Phosphatase