Activity of Caudate Nucleus Neurons in a Visual Fixation Paradigm in Behaving Cats

PLoS One. 2015 Nov 6;10(11):e0142526. doi: 10.1371/journal.pone.0142526. eCollection 2015.

Abstract

Beside its motor functions, the caudate nucleus (CN), the main input structure of the basal ganglia, is also sensitive to various sensory modalities. The goal of the present study was to investigate the effects of visual stimulation on the CN by using a behaving, head-restrained, eye movement-controlled feline model developed recently for this purpose. Extracellular multielectrode recordings were made from the CN of two cats in a visual fixation paradigm applying static and dynamic stimuli. The recorded neurons were classified in three groups according to their electrophysiological properties: phasically active (PAN), tonically active (TAN) and high-firing (HFN) neurons. The response characteristics were investigated according to this classification. The PAN and TAN neurons were sensitive primarily to static stimuli, while the HFN neurons responded primarily to changes in the visual environment i.e. to optic flow and the offset of the stimuli. The HFNs were the most sensitive to visual stimulation; their responses were stronger than those of the PANs and TANs. The majority of the recorded units were insensitive to the direction of the optic flow, regardless of group, but a small number of direction-sensitive neurons were also found. Our results demonstrate that both the static and the dynamic components of the visual information are represented in the CN. Furthermore, these results provide the first piece of evidence on optic flow processing in the CN, which, in more general terms, indicates the possible role of this structure in dynamic visual information processing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal / physiology*
  • Cats
  • Caudate Nucleus / cytology*
  • Caudate Nucleus / physiology*
  • Fixation, Ocular / physiology*
  • Neurons / cytology*
  • Optic Flow / physiology
  • Photic Stimulation

Grants and funding

Funded by Hungarian Brain Research Program Grant KTIA_13_NAP-A-I/15 (AN) (http://www.agykutatas.com/); OTKA/Hungary Grant 83810. (http://www.otka.hu/) (GB). T. Nagypál was a fellow of Talentum Foundation of the Gedeon Richter Plc. (https://www.richter.hu/hu-HU/felelossegvallalas/alapitvanyok/Pages/Richter-Gedeon-Talentum-Alapitvany.aspx). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.