Telencephalic projections of the nucleus rotundus in the pigeon (Columba livia)

Harvey J. Karten; William Hodos

doi:10.1002/cne.901400103

Timing of ascending and descending visual signals predicts the response mode of single cells in the thalamic nucleus rotundus of the pigeon (Columba livia)

Brain Research ◽

10.1016/j.brainres.2006.11.034 ◽

2007 ◽

Vol 1132 ◽

pp. 100-109 ◽

Cited By ~ 3

Author(s):

Kristian Folta ◽

Nikolaus F. Troje ◽

Onur Güntürkün

Keyword(s):

Thalamic Nucleus ◽

Single Cells ◽

Columba Livia ◽

Response Mode ◽

Visual Signals ◽

Nucleus Rotundus

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The Spectral Sensitivity of Single Units in the Nucleus Rotundus of Pigeon, Columba livia

The Journal of General Physiology ◽

10.1085/jgp.57.3.363 ◽

1971 ◽

Vol 57 (3) ◽

pp. 363-384 ◽

Cited By ~ 38

Author(s):

A. M. Granda ◽

S. Yazulla

Keyword(s):

Spectral Sensitivity ◽

Monochromatic Light ◽

Columba Livia ◽

Single Units ◽

Response Functions ◽

Light Stimulation ◽

Sensitivity Functions ◽

Nucleus Rotundus ◽

Intensity Response ◽

Changing Criterion

Responses to diffuse monochromatic light were recorded from single units in the diencephalon of pigeon. Units were both excited and inhibited by light stimulation. Intensity-response functions based on latency measures to the first spike after stimulation were used to generate action spectra. One class of spectral sensitivity functions presumably from rods, showed peak sensitivities near 500 nm: these functions were unaffected by changing criterion values used to generate the functions. A second class of cone functions showed multiple peak sensitivities at 540 nm and 600–620 nm. These units shifted their peak sensitivities with a change in criterion values. Unit response types tended to be localized differentially in the nucleus rotundus. Excitatory units were located in the dorsal half of the nucleus, while inhibitory units were located in the ventral half, with a few exceptions. An attempt was made to integrate the present findings with previous behavioral, electrophysiological, photochemical, and anatomical data in the pigeon.

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Excitatory and inhibitory neurotransmitters in the nucleus rotundus of pigeons

Visual Neuroscience ◽

10.1017/s095252380000938x ◽

1995 ◽

Vol 12 (5) ◽

pp. 819-825 ◽

Cited By ~ 13

Author(s):

Hong-Feng Gao ◽

Gang-Yi Wu ◽

Barrie J. Frost ◽

Shu-Rong Wang

Keyword(s):

Nmda Receptors ◽

Ampa Receptors ◽

Action Potentials ◽

Columba Livia ◽

Visual Responses ◽

Ampa Antagonists ◽

Nucleus Rotundus ◽

Ampa And Nmda Receptors ◽

Inhibitory Transmitter ◽

Excitatory Transmitter

AbstractRotundal neurons in pigeons (Columba livia) were examined for the effects of glutamate and its agonists NMDA and AMPA, antagonists CPP and CNQX, as well as of GABA and its antagonist bicuculline, on visual and tectal stimulation-evoked responses. Glutamate applied by iontophoresis excited all 48 rotundal cells tested, and this excitation was blocked by CNQX but not by CPP in 98% of cases, with 2% of cells being blocked by either CNQX or CPP. Out of 21 cells excited by AMPA, 20 were also excited by NMDA, indicating that AMPA and NMDA receptors may coexist in most rotundal cells. Action potentials were evoked in 36 additional cells by electrical stimulation applied to the tectum and they were also blocked by CNQX but not CPP. Visual responses recorded from a further eight luminance units and 21 motion-sensitive units were also blocked by CNQX and not CPP. On the other hand, GABA inhibited visual responses as well as responses evoked by tectal stimulation. An inhibitory period following tectal stimulation was eliminated by bicuculline. Taken together, these results indicate that glutamate may be an excitatory transmitter acting predominantly through non-NMDA receptors (AMPA receptors) in tectorotundal transmission. Meanwhile, GABA may be an inhibitory transmitter in the pigeon nucleus rotundus.

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