title: Visual stimulation synchronizes or desynchronizes the activity of neuron pairs between the caudate nucleus and the posterior thalamus.
abstract: Recent morphological and physiological studies have suggested a strong relationship between the suprageniculate nucleus (Sg) of the posterior thalamus and the input structure of the basal ganglia, the caudate nucleus (CN) of the feline brain. Accordingly, to clarify if there is a real functional relationship between Sg and CN during visual information processing, we investigated the temporal relations of simultaneously recorded neuronal spike trains of these two structures, looking for any significant cross-correlation between the spiking of the simultaneously recorded neurons. For the purposes of statistical analysis, we used the shuffle and jittering resampling methods. Of the recorded 288 Sg-CN neuron pairs, 26 (9.2%) showed significantly correlated spontaneous activity. Nineteen pairs (6.7%) showed correlated activity during stationary visual stimulation, while 21 (7.4%) pairs during stimulus movement. There was no overlap between the neuron pairs that showed cross-correlated spontaneous activity and the pairs that synchronized their activity during visual stimulation. Thus visual stimulation seems to have been able to synchronize, and also, by other neuron pairs, desynchronize the activity of CN and Sg. In about half of the cases, the activation of Sg preceded the activation of CN by a few milliseconds, while in the other half, CN was activated earlier. Our results provide the first piece of evidence for the existence of a functional cooperation between Sg and CN. We argue that either a monosynaptic bidirectional direct connection should exist between these structures, or a common input comprising of parallel pathways synchronizing them.
authors.affiliation: Dept. of Physiology, Faculty of Medicine, University of Szeged, Dóm tér 10., H-6720 Szeged, Hungary.
authors.forename: Alice
authors.initials: A
authors.lastname: Rokszin
authors.forename: Péter
authors.initials: P
authors.lastname: Gombköto
authors.forename: Antal
authors.initials: A
authors.lastname: Berényi
authors.forename: Zita
authors.initials: Z
authors.lastname: Márkus
authors.forename: Gábor
authors.initials: G
authors.lastname: Braunitzer
authors.forename: György
authors.initials: G
authors.lastname: Benedek
authors.forename: Attila
authors.initials: A
authors.lastname: Nagy
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D002415:Cats; D002421:Caudate Nucleus / Q000166:cytology*; D005260:Female; D008297:Male; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D020656:Posterior Thalamic Nuclei / Q000166:cytology*; D011930:Reaction Time; D013223:Statistics as Topic; D014795:Visual Pathways / Q000502:physiology*