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

Nagypál T, Gombkötő P, Barkóczi B, Benedek G, Nagy A - PLoS ONE (2015)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary.

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.

No MeSH data available.


Related in: MedlinePlus

Marked responses to optic flow stimulation.Panels A and B show the activity of a HFN with a characteristic phasic response to the onset of the optic flow. Panels C and D show the responses of another HFN to static as well as to optic flow stimulation. Note the marked responses of these units to optic flow stimulation. The conventions are the same as in Fig 3.
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pone.0142526.g006: Marked responses to optic flow stimulation.Panels A and B show the activity of a HFN with a characteristic phasic response to the onset of the optic flow. Panels C and D show the responses of another HFN to static as well as to optic flow stimulation. Note the marked responses of these units to optic flow stimulation. The conventions are the same as in Fig 3.

Mentions: Eighty-eight high-firing neurons were analyzed. The mean spontaneous discharge rate was 14.45 spikes/sec (SD: ±6.81). During the static phase 18 neurons increased and 18 neurons decreased their activity significantly (Fig 3C and 3D). Thirty-seven high-firing CN neurons responded to the optic flow stimulus. During the center-out optic flow 16 neurons and during center-in optic flow 20 neurons exhibited increased activity. The visual responses of this group are much clearer and stronger than those of the PANs and TANs (Table 2). Fig 4C and 4D and Fig 6 show the responses of three HFNs to optic flow (one cell with decreased and two cells with increased activity).


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

Nagypál T, Gombkötő P, Barkóczi B, Benedek G, Nagy A - PLoS ONE (2015)

Marked responses to optic flow stimulation.Panels A and B show the activity of a HFN with a characteristic phasic response to the onset of the optic flow. Panels C and D show the responses of another HFN to static as well as to optic flow stimulation. Note the marked responses of these units to optic flow stimulation. The conventions are the same as in Fig 3.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4636356&req=5

pone.0142526.g006: Marked responses to optic flow stimulation.Panels A and B show the activity of a HFN with a characteristic phasic response to the onset of the optic flow. Panels C and D show the responses of another HFN to static as well as to optic flow stimulation. Note the marked responses of these units to optic flow stimulation. The conventions are the same as in Fig 3.
Mentions: Eighty-eight high-firing neurons were analyzed. The mean spontaneous discharge rate was 14.45 spikes/sec (SD: ±6.81). During the static phase 18 neurons increased and 18 neurons decreased their activity significantly (Fig 3C and 3D). Thirty-seven high-firing CN neurons responded to the optic flow stimulus. During the center-out optic flow 16 neurons and during center-in optic flow 20 neurons exhibited increased activity. The visual responses of this group are much clearer and stronger than those of the PANs and TANs (Table 2). Fig 4C and 4D and Fig 6 show the responses of three HFNs to optic flow (one cell with decreased and two cells with increased activity).

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, Faculty of Medicine, University of Szeged, Szeged, Hungary.

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.

No MeSH data available.


Related in: MedlinePlus