Neurons in the globus pallidus do not show correlated activity in the normal monkey, but phase-locked oscillations appear in the MPTP model of parkinsonism

J Neurophysiol. 1995 Oct;74(4):1800-5. doi: 10.1152/jn.1995.74.4.1800.


1. To test the mode of functional connectivity in the basal ganglia circuitry, we studied the activity of simultaneously recorded neurons in the globus pallidus (GP) of a behaving rhesus monkey. The cross-correlograms of pairs of neurons in the GP were compared with those of neurons in the thalamus and frontal cortex and to the cross-correlograms of pallidal pairs after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment. 2. In contrast with cortical and thalamic neuronal activity, almost all pairs (n = 76/81 pairs; 93.8%, 1,629/1,651 histograms; 98.7%) of GP neurons in the normal monkey were not driven by a common input. 3. The monkey was systemically treated with MPTP until the appearance of parkinsonian signs and an intermittent 7- to 11-Hz action/postural tremor. After the MPTP treatment, many pallidal neurons (49/140; 35%) became oscillatory, and 19% (n = 31/162) of pallidal pairs had oscillatory cross-correlograms. 4. These results support the model of parallel processing in the basal ganglia of normal monkeys and suggest a breakdown of the independent activity in the parkinsonian state.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine*
  • Animals
  • Electrophysiology
  • Globus Pallidus / pathology
  • Globus Pallidus / physiopathology*
  • Macaca mulatta / physiology*
  • Neurons / physiology*
  • Oscillometry
  • Parkinson Disease, Secondary / chemically induced*
  • Parkinson Disease, Secondary / physiopathology*
  • Reference Values


  • 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine