OKN-related neurons in the rat nucleus of the optic tract and dorsal terminal nucleus of the accessory optic system receive a direct cortical input

1993 ◽  
Vol 330 (2) ◽  
pp. 147-157 ◽  
Author(s):  
M. Schmidt ◽  
H.-Y. Zhang ◽  
K.-P. Hoffmann
Keyword(s):  
Optic Tract ◽  
Optic System ◽  
Accessory Optic System ◽  
Cortical Input

Microelectrode study of accessory optic tract in the rabbit

1962 ◽  
Vol 202 (3) ◽  
pp. 480-486 ◽  
Author(s):  
Duco Hamasaki ◽  
Elwin Marg
Keyword(s):  
Optic Tract ◽  
Unique Sequence ◽  
Single Units ◽  
Photic Stimulation ◽  
Optic System ◽  
Accessory Optic System ◽  
Physiological Properties ◽  
Intermittent Photic Stimulation ◽  
To Receive

Microelectrodes were used to study the physiological properties of single units from the posterior accessory optic tract-transpeduncular tract in the rabbit. Both on and on-off elements were isolated in the nucleus of the transpeduncular tract. Only one off element was isolated. Intermittent photic stimulation was found to evoke a unique sequence of responses from the accessory optic system. The units gave a good response to the low rates of stimulation, decreased or stopped firing at the intermediate rates, and resumed firing at still higher rates of stimulation. The nucleus of the transpeduncular tract was found to receive its activation from elements in the central part of the retina. Recordings from elements of the nucleus of the posterior accessory optic tract showed that their physiological properties were very similar to those of the nucleus of the transpeduncular tract.

Pharmacological isolation of visual cortical input to the cat accessory optic system: Effects of intravitreal tetrodotoxin on DTN unit responses

1991 ◽  
Vol 6 (2) ◽  
pp. 175-183 ◽  
Author(s):  
Keith L. Grasse
Keyword(s):  
Visual Cortex ◽  
Neural Mechanisms ◽  
Inhibitory Influence ◽  
Optic System ◽  
Accessory Optic System ◽  
Cortical Input ◽  
Before And After ◽  
Contralateral Eye ◽  
Visual Cortical ◽  
Stimulation Of

AbstractDirection-selective responses were recorded from neurons in the dorsal terminal nucleus (DTN) of the cat accessory optic system before and after intravitreal injections of tetrodotoxin (TTX) into the contralateral eye. After approximately 100 min, direction-selective responses driven through stimulation of the contralateral, injected eye were reduced on average by 90%, while direction-selective responses driven through stimulation of the ipsilateral, uninjected eye were not significantly reduced. By 200 min postinjection, ipsilateral direction-selective responses were either equal to or sometimes greater than control values. In the final stages of these experiments (i.e. between 390–830 min after contralateral eye injections), ipsilateral eye responses were on average 30% higher than control. The effects of retinal blockade of the contralateral eye by TTX show that input from the ipsilateral eye alone is sufficient to mediate direction-selective responses in DTN cells. These results and those observed following bicuculline eye injections reported previously (Grasse et al. 1990) demonstrate that direction-selective responses in the DTN driven through stimulation of the contralateral and ipsilateral eyes arise from independent neural mechanisms located in the retina and visual cortex, respectively. Moreover, these findings also suggest that the contralateral eye exerts an inhibitory influence over ipsilateral eye responses which is diminished by TTX injections into the contralateral eye.

Connectivity of the turtle accessory optic system

2003 ◽  
Vol 989 (1) ◽  
pp. 76-90 ◽  
Author(s):  
Amy E Weber ◽  
John Martin ◽  
Michael Ariel
Keyword(s):  
Optic System ◽  
Accessory Optic System

Retinal ganglion cells projecting to the rabbit accessory optic system

1980 ◽  
Vol 190 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Clyde W. Oyster ◽  
John I. Simpson ◽  
Ellen S. Takahashi ◽  
Robert E. Soodak
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Optic System ◽  
Accessory Optic System

Displaced ganglion cells and the accessory optic system of pigeon

1981 ◽  
Vol 195 (2) ◽  
pp. 279-288 ◽  
Author(s):  
Katherine V. Fite ◽  
Nicholas Brecha ◽  
Harvey J. Karten ◽  
Stephen P. Hunt
Keyword(s):  
Ganglion Cells ◽  
Optic System ◽  
Accessory Optic System

Visual receptive field properties in kitten pretectal nucleus of the optic tract and dorsal terminal nucleus of the accessory optic tract

1993 ◽  
Vol 70 (2) ◽  
pp. 814-827 ◽  
Author(s):  
C. Distler ◽  
K. P. Hoffmann
Keyword(s):  
Discharge Rate ◽  
Age Groups ◽  
Optic Tract ◽  
Visual Response ◽  
Stimulus Movement ◽  
Cortical Input ◽  
Preferred Direction ◽  
Pretectal Nucleus ◽  
Adult Cats ◽  
Contralateral Eye

1. Neurons in the pretectal nucleus of the optic tract (NOT) and dorsal terminal nucleus of the accessory optic tract (DTN) were recorded in anesthetized and paralyzed kittens on postnatal days 18 to 48 (P18-P48) as well as in adult cats. 2. Spontaneous as well as stimulus driven discharge rates of NOT-DTN neurons in the youngest kittens (P18-P23) are significantly lower than in older kittens (P27-P33) or adult cats. 3. Visual latencies of NOT-DTN neurons in P18-P23 kittens are significantly longer than in P27-P33 kittens. They further decrease as the animals reach adulthood. 4. Already in the youngest animals recorded in this experimental series (P18) NOT-DTN neurons were selective for ipsiversive horizontal stimulus movement. When expressed as the difference between response strength during stimulation in the preferred and the nonpreferred direction, P18-P23 NOT-DTN neurons are less direction selective than NOT-DTN cells in older animals. However, the normalized directional tuning expressed as percent change in discharge rate per degree change in stimulus direction away from the preferred direction (where discharge rate is set 100%) is about equal in all age groups. 5. NOT-DTN neurons in P18-P23 kittens respond to a rather limited range of stimulus speeds with an optimum at approximately 10 degrees/s. In P27-P33 kittens, NOT-DTN neurons increase their responsive range to higher stimulus speeds. As the animals approach adulthood, the range of effective stimulus speeds further broadens to include very low ones. 6. In P18-P23 kittens, the majority of NOT-DTN neurons is exclusively activated by the contralateral eye; only a few neurons receive an additional input from the ipsilateral eye. In P27-P48 kittens, the influence of the ipsilateral eye has significantly increased but with the majority of NOT-DTN cells still being dominated by the contralateral eye. Finally, in adults, a further strengthening of the ipsilateral input leads to a more binocularly balanced input to NOT-DTN cells. 7. Electrical stimulation in areas 17 and 18 did not elicit orthodromic action potentials in NOT-DTN neurons before P27. Thus the cortical input to the NOT-DTN in kittens becomes functional only at 4 wk of age. 8. In conclusion, the significant changes of visual response properties of NOT-DTN neurons coincide with the time when the cortical input to the NOT-DTN becomes functional.(ABSTRACT TRUNCATED AT 400 WORDS)

Membrane Properties and Monosynaptic Retinal Excitation of Neurons in the Turtle Accessory Optic System

1997 ◽  
Vol 78 (2) ◽  
pp. 614-627 ◽  
Author(s):  
Naoki Kogo ◽  
Michael Ariel
Keyword(s):  
Receptive Field ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Membrane Properties ◽  
Retinal Ganglion ◽  
Optic System ◽  
Accessory Optic System ◽  
Postsynaptic Potentials ◽  
Synaptic Inputs ◽  
Bon Cells

Kogo, Naoki and Michael Ariel. Membrane properties and monosynaptic retinal excitation of neurons in the turtle accessory optic system. J. Neurophysiol. 78: 614–627, 1997. Using an eye-attached isolated brain stem preparation of a turtle, Pseudemys scripta elegans, in conjunction with whole cell patch techniques, we recorded intracellular activity of accessory optic system neurons in the basal optic nucleus (BON). This technique offered long-lasting stable recordings of individual synaptic events. In the reduced preparation (most of the dorsal structures were removed), large spontaneous excitatory synaptic inputs [excitatory postsynaptic potentials (EPSPs)] were frequently recorded. Spontaneous inhibitory postsynaptic potentials were rarely observed except in few cases. Most EPSPs disappeared after injection of lidocaine into the retina. A few EPSPs of small size remained, suggesting that these EPSPs either were from intracranial sources or may have been miniature spontaneous synaptic potentials from retinal ganglion cell axon terminals. Population EPSPs were synchronously evoked by electrical stimulation of the contralateral optic nerve. Their constant onset latency and their ability to follow short-interval paired stimulation indicated that much of the population EPSP's response was monosynaptic. Visually evoked BON spikes and EPSP inputs to BON showed direction sensitivity when a moving pattern was projected onto the entire contralateral retina. With the use of smaller moving patterns, the receptive field of an individual BON cell was identified. A small spot of light, projected within the receptive field, guided the placement of a bipolar stimulation electrode to activate retinal ganglion cells that provided input to that BON cell. EPSPs evoked by this retinal microstimulation showed features of unitary EPSPs. Those EPSPs had distinct low current thresholds. Recruitment of other inputs was only evident when the stimulation level was increased substantially above threshold. The average size of evoked unitary EPSPs was 7.8 mV, confirming the large size of synaptic inputs of this system relative to nonsynaptic noise. EPSP shape was plotted (rise time vs. amplitude), with the use of either evoked unitary EPSPs or spontaneous EPSPs. Unlike samples of spontaneous EPSPs, data from many unitary EPSPs formed distinct clusters in these scatterplots, indicating that these EPSPs had a unique shape among the whole population of EPSPs. In most BON cells studied, hyperpolarization-activated channels caused a slow depolarization sag that reached a plateau within 0.5–1 s. This property suggests that BON cells may be more complicated than a simple site for convergence of direction-sensitive retinal ganglion cells to form a central retinal slip signal for control of oculomotor reflexes.

Sign in / Sign up

Export Citation Format

Share Document