Bottlebrush dendritic endings and large dendritic fields: Motion-detecting neurons in the tectofugal pathway

1998 ◽  
Vol 396 (3) ◽  
pp. 399-414 ◽  
Author(s):  
Harald Luksch ◽  
Kevin Cox ◽  
Harvey J. Karten
Keyword(s):  
Dendritic Fields ◽  
Tectofugal Pathway

Organization of synaptic inputs to paracerebral feeding command interneurons of Pleurobranchaea californica. I. Excitatory inputs

1983 ◽  
Vol 49 (6) ◽  
pp. 1517-1538 ◽  
Author(s):  
M. P. Kovac ◽  
W. J. Davis ◽  
E. M. Matera ◽  
R. P. Croll
Keyword(s):  
Motor Behavior ◽  
Lucifer Yellow ◽  
Electrical Synapse ◽  
Functional Specialization ◽  
Synaptic Inputs ◽  
Rhythmic Motor ◽  
Pleurobranchaea Californica ◽  
Long Latency ◽  
Chemical Inputs ◽  
Dendritic Fields

Neurons presynaptic to the phasic paracerebral feeding command interneurons (PCP's; Ref. 55) of Pleurobranchaea were located in the isolated central nervous system (CNS) and studied anatomically by lucifer yellow injection and physiologically by current injection and intracellular recording in normal and ion-substituted seawater during quiescence and fictive feeding. The present paper describes excitatory inputs to PCP's, while the accompanying paper (54) reports inhibitory inputs. Monosynaptic excitors (MSEs) are a group of at least three monopolar neurons per hemiganglion. Two have similar dendritic structures and functional effects. Each MSE monosynaptically excites the PCP's and fires action-potential bursts in phase with PCP bursts during fictive feeding. The class I electrotonic neuron (ETI) is a single, identified monopolar neuron per hemiganglion with a sparse dendritic arborization and no descending axon in the cerebrobuccal connective (CBC). The ETI is coupled with PCP's only by means of a non-rectifying electrical synapse. Paradoxically, ETI receives opposite synaptic inputs from PCP's and fires in antiphase with PCP's during fictive feeding. Class II electrotonic neurons (ETII's) are a group of at least two identified multipolar neurons per hemiganglion with indistinguishable dendritic architectures and similar but distinguishable functional effects. Each cell is coupled with PCP's by means of a nonrectifying electrical synapse. One of the ETII's also delivers graded, long-latency poly-synaptic chemical inputs to PCP's. ETII's have descending axons in the CBC, elicit fictive feeding when depolarized, and fire cyclically and in phase with PCP's during fictive feeding. Polysynaptic excitors (PSEs) are a group of at least two identified monopolar neurons per hemiganglion with similar elaborate dendritic fields and functional effects. Each cell excites PCP's by a long-latency, relatively nongraded polysynaptic pathway. PSEs also have descending axons in the ipsilateral CBC, elicit fictive feeding when depolarized, and fire in phase with PCP's during fictive feeding. PSEs and ETII's are here recognized as subclasses of neurons previously identified as paracerebral neurons. They are inhibited by the same neurons that supply recurrent inhibition to PCP's (47), share excitatory inputs with PCP's, and exhibit a similar "command" capacity. This study thus documents redundancy and functional specialization within a command system controlling a relatively complex rhythmic motor behavior.

Morphology of cells in the ganglion cell layer during development of the rat retina

1980 ◽  
Vol 208 (1173) ◽  
pp. 433-446 ◽  
Keyword(s):  
Ganglion Cell ◽  
Time Course ◽  
Ganglion Cell Layer ◽  
Ganglion Cells ◽  
Cell Layer ◽  
Type I ◽  
Adult Size ◽  
Rat Retina ◽  
Adult Rat ◽  
Dendritic Fields

The development of the cells in the ganglion cell layer in the rat retina has been studied from 3 to 30 days of age postnatal by means of Golgi-stained whole-mounted retinae. The retina grows rapidly from birth to ten days of age and then more slowly from 10 to 30 days of age. The different classes of ganglion cell can be clearly recognized by 10 days of age, but type I ganglion cells with a size comparable to those found in the adult rat retina are not seen until thirty days of age. Type II cells may attain their adult size before type I cells do. The growth of the retina and the resulting decrease in cell density in the ganglion cell layer occur with the same time course as the increase in the size of the cell soma and their dendritic fields.

Diversity of neuronal phenotypes expressed in monolayer cultures from immature rabbit retina

1994 ◽  
Vol 11 (4) ◽  
pp. 629-642 ◽  
Author(s):  
V. Möckel ◽  
S. Löhrke ◽  
H.-D. Hofmann
Keyword(s):  
Amacrine Cells ◽  
Cell Number ◽  
Retinal Cell ◽  
Gaba Uptake ◽  
Cell Type ◽  
Quisqualic Acid ◽  
Monolayer Cultures ◽  
Dendritic Fields

AbstractWe have used monolayer cultures prepared from early postnatal rabbit retinae (days 2–5) by the sandwich technique to study the capacity of immature neurons to express specific neuronal phenotypes in a homogeneous in vitro environment. Applying morphological, immunocytochemical, and autoradiographic criteria, we demonstrate that a variety of phenotypes could be distinguished after 7–14 days in vitro, and correlated with known retinal cell types. Bipolar cell-like neurons (approximately 4% of total cell number) were identified by cell type-specific monoclonal antibodies (115A10) and their characteristic bipolar morphology. Small subpopulations (about 1%) of GABA-immunoreactive neurons acquired elaborate morphologies strikingly similar to those of A- and B-type horizontal cells. Amongst putative amacrine cells several different subpopulations could be classified. GABA-immunoreactive amacrine-like neurons (6.5%), which also showed high affinity [3H]-GABA uptake, comprised cells of varying size and shape and could be subdivided into subpopulations with respect to their response to different glutamate receptor agonists (NMDA, kainic acid, quisqualic acid). In addition, a small percentage of [3H]-GABA accumulating cells with large dendritic fields showed tyrosine-hydroxylase immunoreactivity. Presumptive glycinergic amacrine cells (18.5%) were rather uniform in shape and had small dendritic fields. Release of [3H]-glycine from these neurons was evoked by kainic and quisqualic acid but not by NMDA. Small [3H]-glutamate accumulating neurons with few short processes were the most frequent cell type (73%). This cell type also exhibited opsin immunoreactivity and probably represented incompletely differentiated photoreceptor cells. Summing the numbers of characterized cells indicated that we were able to attribute a defined retinal phenotype to most, if not all of the cultured neurons. Thus, we have demonstrated that immature neuronal cells growing in monolayer cultures, in the absence of a structured environment, are capable of maintaining or producing specific morphological and functional properties corresponding to those expressed in vivo. These results stress the importance of intrinsic factors for the regulation of neuronal differentiation. On the other hand, morphological differentiation was far from perfect indicating the requirement for regulatory factors.

Horizontal cell morphology in nocturnal and diurnal primates: A comparison between owl-monkey (Aotus) and capuchin monkey (Cebus)

2005 ◽  
Vol 22 (4) ◽  
pp. 405-415 ◽  
Author(s):  
SETSUKO N. DOS SANTOS ◽  
JOSÉ WESLEY L. DOS REIS ◽  
MANOEL DA SILVA FILHO ◽  
JAN KREMERS ◽  
LUIZ CARLOS L. SILVEIRA
Keyword(s):  
Cell Morphology ◽  
Horizontal Cell ◽  
Horizontal Cells ◽  
Capuchin Monkey ◽  
Close Relative ◽  
Axon Terminals ◽  
Life Styles ◽  
Owl Monkey ◽  
H1 Cells ◽  
Dendritic Fields

Horizontal cell morphology was studied in the retina of the nocturnal owl-monkey,Aotus, and compared with that of its diurnal, close relative, the capuchin monkey,Cebus. Cells were initially labeled with DiI and the staining was later photoconverted in a stable precipitated using DAB as chromogen. The sizes of cell bodies, dendritic fields, and axon terminals, number of dendritic clusters, intercluster spacing, and intercone spacing were measured at increasing eccentricities. Two distinct morphological classes of horizontal cells were identified, which resembled those of H1 and H3 cells described in diurnal monkeys. A few examples of a third class, possibly corresponding to the H2 cells of diurnal monkeys, were labeled. Both H1 and H3 cells increased in size and had increasing numbers of dendritic clusters with eccentricity. H3 cells were larger and had a larger number of dendritic clusters than H1 cells. Owl-monkey H1 cells had larger dendritic fields than capuchin monkey H1 cells at all quadrants in the central and midperipheral retinal regions, but the difference disappeared in the far periphery. Owl-monkey and capuchin monkey H1 cells had about the same number of dendritic clusters across eccentricity. As owl-monkey H1 cells were larger than capuchin monkey H1 cells, the equal number of clusters in these two primates was due to the fact that they were more spaced in the owl-monkey cells. H1 intercluster distance closely matched intercone spacing for both the owl-monkey and capuchin monkey retinas. On the other hand, H3 intercluster distance was larger than intercone spacing in the retina of both primates. Owl-monkey H1 axon terminals had 2–3 times more knobs than capuchin monkey H1 axon terminals in spite of having about the same size and, consequently, knob density was 2–3 times higher for owl-monkey than capuchin monkey H1 axon terminals across all eccentricities. The differences observed between owl-monkey and capuchin monkey horizontal cells, regarding the morphology of their dendritic trees and axon terminals, may be related to the differences found in the cone-to-rod ratio in the retina of these two primates. They seem to represent retinal specializations to the nocturnal and diurnal life styles of the owl-monkey and capuchin monkey, respectively.

Mosaic properties of midget and parasol ganglion cells in the marmoset retina

2005 ◽  
Vol 22 (4) ◽  
pp. 395-404 ◽  
Author(s):  
BRETT A. SZMAJDA ◽  
ULRIKE GRÜNERT ◽  
PAUL R. MARTIN
Keyword(s):  
Ganglion Cells ◽  
World Monkey ◽  
Spatial Vision ◽  
Common Marmoset ◽  
Field Size ◽  
Dendritic Field ◽  
Consistent Feature ◽  
Dendritic Fields ◽  
Low Coverage

We measured mosaic properties of midget and parasol ganglion cells in the retina of a New World monkey, the common marmosetCallithrix jacchus. We addressed the functional specialization of these populations for color and spatial vision, by comparing the mosaic of ganglion cells in dichromatic (“red–green color blind”) and trichromatic marmosets. Ganglion cells were labelled by photolytic amplification of retrograde marker (“photofilling”) following injections into the lateral geniculate nucleus, or by intracellular injection in anin vitroretinal preparation. The dendritic-field size, shape, and overlap of neighboring cells were measured. We show that in marmosets, both midget and parasol cells exhibit a radial bias, so that the long axis of the dendritic field points towards the fovea. The radial bias is similar for parasol cells and midget cells, despite the fact that midget cell dendritic fields are more elongated than are those of parasol cells. The dendritic fields of midget ganglion cells from the same (ON or OFF) response-type array show very little overlap, consistent with the low coverage of the midget mosaic in humans. No large differences in radial bias, or overlap, were seen on comparing retinae from dichromatic and trichromatic animals. These data suggest that radial bias in ganglion cell populations is a consistent feature of the primate retina. Furthermore, they suggest that the mosaic properties of the midget cell population are associated with high spatial resolution rather than being specifically associated with trichromatic color vision.

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