Lagged cells in alert monkey lateral geniculate nucleus

2008 ◽  
Vol 25 (5-6) ◽  
pp. 647-659 ◽  
Author(s):  
ALAN B. SAUL
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Extracellular Recording ◽  
Macaque Monkey ◽  
Direction Selectivity ◽  
Alert Monkey ◽  
Lateral Geniculate ◽  
Multiple Dimensions ◽  
Wide Range ◽  
Lagged Cells ◽  
Response Timing

AbstractFive lagged cells were recognized by extracellular recording in the lateral geniculate nucleus of an awake, behaving macaque monkey. Previous reports of lagged cells were all in the anesthetized cat. Both parvocellular and magnocellular lagged cells were observed. Response timing was distributed continuously across the population, and both sustained and transient responses were seen in the magnocellular subpopulation. Cortex thus receives signals with a wide range of timing, which can mediate direction selectivity across multiple dimensions.

Action of brain stem reticular afferents on lagged and nonlagged cells in the cat lateral geniculate nucleus

1992 ◽  
Vol 68 (3) ◽  
pp. 673-691 ◽  
Author(s):  
A. L. Humphrey ◽  
A. B. Saul
Keyword(s):  
Brain Stem ◽  
Lateral Geniculate Nucleus ◽  
Reticular Formation ◽  
Discharge Rate ◽  
Cell Discharge ◽  
Lateral Geniculate ◽  
Lagged Cells ◽  
Response Timing ◽  
X Cells ◽  
Y Cells

1. The A-laminae of the cat lateral geniculate nucleus (LGN) contain two distinct groups of relay neurons: lagged and nonlagged cells. The groups differ in the pattern, timing, and amplitude of response to flashing spots. At spot onset, nonlagged cells discharge at short latency with an excitatory transient; in lagged cells this transient is supplanted by an inhibitory dip and a delayed latency to discharge. At spot offset, lagged cell discharge decays more slowly than in nonlagged cells. Here we have investigated the facilitatory influence of the brain stem reticular formation on the response properties of lagged X-cells (XL) and nonlagged X- and Y-cells (XN and YN). We were particularly interested in whether the inhibitory dip and sluggish response of lagged cells could be reversed during brain stem activation and the cells induced to respond like nonlagged cells. The peribrachial region (PB) of the pontine reticular formation was stimulated electrically with the use of 1,100-ms-long pulse trains that were paired with flashing spot stimuli. 2. Stimulation of PB led to an increase in the amplitude of visually evoked discharge in lagged and nonlagged cells. Compared with their response to spot stimulation alone, the average PB-evoked increase in mean discharge rate was greater than 50% in both groups. The mean discharge rate during PB plus spot stimulation was somewhat higher for XN-cells than for YN- and XL-cells, reflecting the relatively higher discharge rate among XN-cells during spot stimulation alone. 3. Two measures of response timing characterize lagged and nonlagged cells: latency to half-maximal discharge at spot onset (half rise) and latency to half-minimal discharge at spot offset (half fall). Among XN- and YN-cells, PB stimulation had no significant effect on these two latencies; among XL-cells, both latencies were reduced by 43 and 35%, respectively, on average. 4. During spot stimulation alone, all lagged cells were distinguishable from all nonlagged cells in having half-rise and half-fall latencies greater than 60 ms. Despite the reduction among XL-cells in these 2 latencies during PB stimulation, all but 2 of the 40 XL-cells maintained laggedlike latencies. The majority (95%) of XL-cells remained unambiguously lagged on these measures during brain stem stimulation. 5. During spot stimulation alone, 30 of 40 XL-cells tested displayed a prominent and often long-lasting inhibitory dip in discharge starting approximately 45 ms after spot onset. During PB stimulation only three cells lost the dip.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of fixational saccades on response timing in macaque lateral geniculate nucleus

2010 ◽  
Vol 27 (5-6) ◽  
pp. 171-181 ◽  
Author(s):  
ALAN B. SAUL
Keyword(s):  
Eye Movements ◽  
Lateral Geniculate Nucleus ◽  
Alert Monkey ◽  
Visual Thalamus ◽  
Lateral Geniculate ◽  
Cortical Responses ◽  
The Times ◽  
Response Timing ◽  
Fixational Saccades ◽  
Display Monitor

AbstractEven during active fixation, small eye movements persist that might be expected to interfere with vision. Numerous brain mechanisms probably contribute to discounting this jitter. Changes in the timing of responses in the visual thalamus associated with fixational saccades are considered in this study. Activity of single neurons in alert monkey lateral geniculate nucleus (LGN) was recorded during fixation while pseudorandom visual noise stimuli were presented. The position of the stimulus on the display monitor was adjusted based on eye position measurements to control for changes in retinal locations due to eye movements. A method for extracting nonstationary first-order response mechanisms was applied, so that changes around the times of saccades could be observed. Saccade-related changes were seen in both amplitude and timing of geniculate responses. Amplitudes were greatly reduced around saccades. Timing was retarded slightly during a window of about 200 ms around saccades. That is, responses became more sustained. These effects were found in both parvocellular and magnocellular neurons. Timing changes in LGN might play a role in maintaining cortical responses to visual stimuli in the presence of eye movements, compensating for the spatial shifts caused by saccades via these shifts in timing.

NMDAR-1 staining in the lateral geniculate nucleus of normal and visually deprived cats

2000 ◽  
Vol 17 (2) ◽  
pp. 187-196 ◽  
Author(s):  
JOKUBAS ZIBURKUS ◽  
MARTHA E. BICKFORD ◽  
WILLIAM GUIDO
Keyword(s):  
Nmda Receptors ◽  
Lateral Geniculate Nucleus ◽  
Cell Labeling ◽  
Acid Decarboxylase ◽  
Thalamic Nuclei ◽  
Neurofilament Protein ◽  
Lateral Geniculate ◽  
Wide Range ◽  
Soma Size ◽  
Adult Cats

In normal adult cats, a monoclonal antibody directed toward the NR-1 subunit of the N-methyl-d-aspartate (NMDA) receptor (Pharmingen, clone 54.1) produced dense cellular and neuropil labeling throughout all layers of the lateral geniculate nucleus (LGN) and adjacent thalamic nuclei, including the thalamic reticular, perigeniculate, medial intralaminar, and ventral lateral geniculate nuclei. Cellular staining revealed well-defined somata, and in some cases proximal dendrites. NMDAR-1 cell labeling was also evident in the LGN of early postnatal kittens, suggesting that developing LGN cells possess this receptor subunit at or before eye opening. Within the A-layers of the adult LGN, staining encompassed a wide range of soma sizes. Soma size comparisons of NMDAR-1 stained cells with those stained with an antibody directed toward a nonphosphorylated neurofilament protein (SMI-32), which selectively stains Y-relay cells (Bickford et al., 1998), or an antibody to glutamic acid decarboxylase (GAD), which stains for GABAergic interneurons, suggested that NMDA receptors are utilized by relay cells and interneurons. NMDAR-1 staining was also observed in the LGN of cats with early monocular lid suture. Although labeling was apparent in both deprived and nondeprived A-layers of LGN, the distribution of soma sizes was significantly different. In the deprived A-layers of LGN, staining was limited to small- and medium-sized cells. Cells with relatively large soma were lacking. However, cell density measurements as well as soma size comparisons with cells stained for Nissl substance suggested these differences were due to deprivation-induced cell shrinkage and not to a loss of NMDAR-1 staining in Y-cells. Taken together, these results suggest that NMDA receptors are utilized by both relay cells and interneurons in LGN and that alterations in early visual experience do not necessarily affect the expression of NMDA receptors in the LGN.

Cell types and response timings in the medial interlaminar nucleus and C-layers of the cat lateral geniculate nucleus

1999 ◽  
Vol 16 (3) ◽  
pp. 513-525 ◽  
Author(s):  
ALLEN L. HUMPHREY ◽  
ADITYA MURTHY
Keyword(s):  
Cell Types ◽  
Direction Selectivity ◽  
Extrastriate Cortex ◽  
Cell Group ◽  
Absolute Phase ◽  
Long Latency ◽  
Lagged Cells ◽  
Discharge Patterns ◽  
Response Timing ◽  
X Cells

Previous evidence concerning the physiological cell classes in the medial interlaminar nucleus (MIN) has been conflicting. We reexamined the MIN using standard functional tests to distinguish X-, Y- and W-cells. Discharge patterns to flashing spots also were used to identify some cells as lagged or nonlagged, as previously done for the geniculate A-layers. Also, each cell's response timing (latency and absolute phase) was measured from discharges to a spot undergoing sinusoidal luminance modulation. Of 71 MIN cells, 48% were Y, 27% were W, 8% were X, and 17% were unclassifiable. Lagged and nonlagged discharge profiles were observed in each cell group, with 28% of all cells being lagged. Lagged cells displayed a response suppression and long latency to discharge following spot onset, and a slow decay in firing at spot offset that was often preceded by a transient discharge. These profiles were indistinguishable from those of lagged cells in the A-layers. MIN cells also were heterogeneous in response timing, displaying a range of latency and absolute phase values similar to that in the A-layers. We extended these analyses to 27 cells in the geniculate C-layers. In layer C, 35% of cells were Y, 10% were X, 25% were W, and 30% were unclassifiable. About 11% had lagged profiles, and were X-cells or unclassifiable cells. Layers C1 and C2 contained only W-cells and no lagged profiles. The range of timings in the C-layers was somewhat narrower than in the MIN. Overall, these results show that the MIN contains a greater variety of functional cell classes than heretofore appreciated. Further, it appears that mechanisms which create different timing delays in the A-layers also exist in the MIN and layer C. These timings may contribute to direction selectivity in extrastriate cortex.

Expression of MARCKS mRNA in lateral geniculate nucleus and visual cortex of normal and monocularly deprived macaque monkeys

2002 ◽  
Vol 19 (5) ◽  
pp. 633-643 ◽  
Author(s):  
NORIYUKI HIGO ◽  
TAKAO OISHI ◽  
AKIKO YAMASHITA ◽  
KEIJI MATSUDA ◽  
MOTOHARU HAYASHI
Keyword(s):  
Protein Kinase ◽  
Lateral Geniculate Nucleus ◽  
Macaque Monkey ◽  
Monocular Deprivation ◽  
Major Protein ◽  
Area 17 ◽  
Double Labeling ◽  
Α Subunit ◽  
Kinase Substrate ◽  
Lateral Geniculate

We performed a nonradioactive in situ hybridization histochemistry (ISH) study of the lateral geniculate nucleus (LGN) and the primary visual area (area 17) of the macaque monkey to investigate mRNA expression of the myristoylated alanine-rich C-kinase substrate (MARCKS), a major protein kinase C (PKC) substrate. In the LGN, intense hybridization signals were observed in both magnocellular neurons (layers 1 and 2) and parvocellular neurons (layers 3 to 6). Double labeling using ISH and immunofluorescence revealed that MARCKS mRNA was coexpressed with the α-subunit of type II calcium/calmodulin-dependent protein kinase, indicating that MARCKS mRNA is also expressed in koniocellular neurons in the LGN. GABA-immunoreactive neurons in the LGN did not contain MARCKS mRNA, indicating that MARCKS mRNA is not expressed in inhibitory interneurons. The signals were generally weak in area 17, and intense signals were restricted to large neurons in layers IVB, V, and VI. GABA-immunoreactive neurons in layers II–VI of area 17 did not contain MARCKS mRNA. Double-label ISH revealed that MARCKS mRNA was coexpressed with mRNA of GAP-43, another PKC substrate, in neurons of both the LGN and area 17. To determine whether the expression of MARCKS mRNA is regulated by retinal activity, we performed ISH in the LGN and area 17 of monkeys deprived of monocular visual input by tetrodotoxin. After monocular deprivation for 5 to 30 days, MARCKS mRNA was down-regulated in the LGN, but not in area 17. These results suggest that MARCKS mediates the activity-dependent changes in the excitatory relay neurons in the LGN.

Correlates of motor planning and postsaccadic fixation in the macaque monkey lateral geniculate nucleus

2005 ◽  
Vol 168 (1-2) ◽  
pp. 62-75 ◽  
Author(s):  
D. W. Royal ◽  
Gy. Sáry ◽  
J. D. Schall ◽  
V. A. Casagrande
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Motor Planning ◽  
Macaque Monkey ◽  
Lateral Geniculate

The effect of contrast on the visual response of lagged and nonlagged cells in the cat lateral geniculate nucleus

1992 ◽  
Vol 9 (5) ◽  
pp. 515-525 ◽  
Author(s):  
E. Hartveit ◽  
P. Heggelund
Keyword(s):  
Dynamic Response ◽  
Lateral Geniculate Nucleus ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Visual Response ◽  
Contrast Gain ◽  
Lateral Geniculate ◽  
Response Range ◽  
Lagged Cells ◽  
X Cells ◽  
Y Cells

AbstractThe response vs. contrast characteristics of different cell classes in the dorsal lateral geniculate nucleus (LGN) were compared. The luminance of a stationary flashing light spot was varied stepwise while the background luminance was constant. Lagged X cells had lower slope of the response vs. contrast curve (contrast gain), and they reached the midpoint of the response range over which the cells' response varied (dynamic response range) at higher contrasts than nonlagged X cells. These results indicated that nonlagged cells are well suited for detection of small contrasts, whereas lagged cells may discriminate between contrasts over a larger range. The contrast gain and the contrast corresponding to the midpoint of the dynamic response range were similar for X and Y cells. The latency to onset and to half-rise of the visual response decreased with increasing contrast, most pronounced for lagged cells. Even at the highest contrasts, the latency of lagged cells remained longer than for nonlagged cells. For many lagged cells, the latency to half-fall decreased with increasing contrast. It is shown that the differences in the response vs. contrast characteristics between lagged and nonlagged X cells in the cat are similar to the differences between the parvocellular and magnocellular neurones in the monkey.

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