Dopaminergic mechanisms in subthalamic nucleus of rat: analysis using horseradish peroxidase and microiontophoresis

Gerald Campbell, Michael J. Eckardt, Forrest F. Weight

Research output: Contribution to journalArticle

102 Citations (Scopus)

Abstract

Afferent connections to the subthalamic nucleus (STN) were studied by microiontophoretically injecting horseradish peroxidase (HRP) into the STN and studying its retrograde transport. Remotely labelled neurons were frequently observed in both the globus pallidus and the pars compacta region of substantia nigra. In addition, individually labelled neurons were occasionally found in other brain regions. The sensitivity of neurons in the STN to dopamine (DA) was studied by applying DA to neurons in the STN by microiontophoresis. Three patterns of response to DA were observed. The most frequent response, observed in 46% of the STN neurons studied, was a decrease in the discharge frequency. In 15% of the neurons there was an increased frequency of firing. Eleven percent of the neurons exhibited a mixed response consisting of an initial depression of discharge rate followed by a delayed increase. The responses of STN neurons to DA were not antagonized by iontophoretically applied haloperidol. In neurons whose firing frequency was decreased by DA, the iontophoretic application of apomorphine and norepinephrine also decreased discharge rate. The observations of HRP-labelled neurons in the pars compacta region of substantia nigra following injection of HRP into the STN together with the DA responsiveness of STN neurons suggest the possibility of a dopaminergic nigro-subthalamic pathway.

Original languageEnglish (US)
Pages (from-to)261-270
Number of pages10
JournalBrain Research
Volume333
Issue number2
DOIs
StatePublished - May 6 1985
Externally publishedYes

Fingerprint

Subthalamic Nucleus
Horseradish Peroxidase
Neurons
Dopamine
Dopaminergic Neurons
Globus Pallidus
Apomorphine
Haloperidol
Norepinephrine
Injections

Keywords

  • dopamine
  • horseradish peroxidase
  • iontophoresis
  • substantia nigra
  • subthalamic nucleus

ASJC Scopus subject areas

  • Developmental Biology
  • Molecular Biology
  • Clinical Neurology
  • Neuroscience(all)

Cite this

Dopaminergic mechanisms in subthalamic nucleus of rat : analysis using horseradish peroxidase and microiontophoresis. / Campbell, Gerald; Eckardt, Michael J.; Weight, Forrest F.

In: Brain Research, Vol. 333, No. 2, 06.05.1985, p. 261-270.

Research output: Contribution to journalArticle

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