Elsevier

Brain Research

Volume 22, Issue 2, 27 August 1970, Pages 163-179
Brain Research

Intracellular responses of caudate neurons to brain stem stimulation

https://doi.org/10.1016/0006-8993(70)90002-8Get rights and content

Abstract

Intracellular recordings were made of responses of caudate neurons to stimulation of substantia nigra and adjacent brain stem structures in cats. The locations of brain stem stimulating points which evoked responses in caudate neurons mapped a pathway generally similar to the dopaminergic nigro-striatal tract which was previously described by histochemical means. Lesions in the central median-parafascicular complex of the thalamus did not prevent these nigro-caudate responses from being elicited.

Responses in caudate neurons to nigral and supranigral stimuli varied in form, but often included EPSP-IPSP sequences. In such cases the duration of the ‘IPSP’ was always shorter than those evoked in the same neurons by precruciate cortical stimulations or by anterior thalamic stimuli.

Effects of stimulus intensity and frequency were assessed. Increases in stimulus intensity increased the amplitude, but not the duration of the intracellular membrane responses. Bursts of high frequency stimulation evoked poststimulus depolarizations of long duration. The possible significance of these long depolarizations for understanding the functions of caudate neurons was discussed.

Reference (25)

  • ConnorJ.D.

    Caudate unit responses to nigral stimuli: evidence for a possible nigro-neostriatal pathway

    Science

    (1968)
  • DichterM.A. et al.

    Penicillin-induced interictal discharges from the cat hippocampus. I. Characteristics and topographical features

    J. Neurophysiol.

    (1969)
  • Cited by (120)

    • The History of the Basal Ganglia: Cells and Circuits

      2016, Handbook of Behavioral Neuroscience
      Citation Excerpt :

      Intracellular recordings are preferred for determining synaptic sign, because they reveal synaptic potentials, even subthreshold ones, and monosynaptic responses can be differentiated from polysynaptic ones by their constant latencies. An intracellular recording study by Hull et al. (1970) described a sequence consisting of a depolarizing synaptic potential followed by a longer lasting hyperpolarization in most neurons. In their experiments, the responses of striatal neurons to substantia nigra stimulation were comparable to those from the cortex or thalamus, and were tentatively identified as a monosynaptic excitation followed by polysynaptic inhibition, perhaps arising from intrastriatal connections.

    • Gating of Cortical Input Through the Striatum

      2016, Handbook of Behavioral Neuroscience
      Citation Excerpt :

      In the intact brain the membrane potential of striatal medium spiny projection neurons (MSNs) spontaneously alternates between two apparently stable states, a very polarized resting potential known as “Down-state” and a close-to-threshold depolarized potential known as “Up-state” (Fig. 22.1). Reports of this alternation can be traced back to early in vivo intracellular recordings of striatal neurons performed in the 1970s and 1980s (Hull et al., 1970; Wilson and Groves, 1981; Yim and Mogenson, 1988). Subsequent studies led to the view that some processes enable MSN firing by driving the membrane potential to the Up-state, while additional processes induce firing during the Up-state (O’Donnell and Grace, 1995; Stern et al., 1998).

    • Glutamate in dopamine neurons: Synaptic versus diffuse transmission

      2008, Brain Research Reviews
      Citation Excerpt :

      Glutamate immunoreactivity was not sufficient evidence to prove that glutamate was being used as co-transmitter. However, electrophysiological data was then obtained demonstrating that rapid excitatory synaptic responses could be evoked in striatal neurons by extracellular stimulation in DA cell body areas or in the medial forebrain bundle (Hull et al., 1970, 1973; Kitai et al., 1975). Moreover, recent work has shown that local application of a D2 receptor agonist at the site of stimulation inhibits the generation of glutamatergic EPSPs in striatal neurons, suggesting that D2 responsive, putative DA neurons (and not fibres of passage), are indeed responsible for such EPSPs (Chuhma et al., 2004).

    View all citing articles on Scopus
    View full text