"Real time" measurement of endogenous dopamine release during short trains of pulses in slices of rat neostriatum and nucleus accumbens: role of autoinhibition

Naunyn Schmiedebergs Arch Pharmacol. 1991 Dec;344(6):623-9. doi: 10.1007/BF00174745.


Release of endogenous dopamine elicited in slices of rat neostriatum or nucleus accumbens by a single electric pulse or by trains of 4 or 10 pulses was examined using fast cyclic voltammetry. Single electric pulses gave rise to a marked and transient increase in the extracellular concentration of dopamine in the neostriatum (by 0.43 mumol/l) and nucleus accumbens (by 0.39 mumol/l). The overflow elicited by subsequent pulses delivered at a frequency of 0.2 Hz caused separate but much smaller peaks of dopamine concentration, whereas the overflow elicited by subsequent pulses delivered at 1 Hz caused only a shoulder in the descending limb of the peak due to pulse 1. Four pulses at 5 Hz produced a monophasic response that was higher than the single pulse-evoked peak. Nomifensine 1 mumol/l greatly increased and prolonged the evoked overflow of dopamine. In the absence of nomifensine, metoclopramide 0.3 mumol/l did not change the response to a single pulse or 4 pulses delivered at 0.2 Hz but increased the response to 4 or 10 pulses at 1 Hz and to 4 pulses at 5 Hz. In the presence of nomifensine, metoclopramide increased the response to a single pulse as well as, to a greater extent, the response to 4 pulses at 0.2 Hz and 4 pulses at 1 Hz. Sulpiride 1 mumol/l produced effects similar to those of metoclopramide in the neostriatum in the presence of nomifensine.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / drug effects
  • Brain / metabolism*
  • Dopamine / metabolism*
  • Electric Stimulation
  • Male
  • Metoclopramide / pharmacology
  • Nomifensine / pharmacology
  • Rats
  • Rats, Inbred Strains
  • Receptors, Dopamine / drug effects
  • Sulpiride / pharmacology


  • Receptors, Dopamine
  • Nomifensine
  • Sulpiride
  • Metoclopramide
  • Dopamine