Dendritic morphology of an inhibitory retinal interneuron enables simultaneous local and global synaptic integration

2022 ◽  
pp. JN-RM-0695-21
Author(s):  
Espen Hartveit ◽  
Margaret Lin Veruki ◽  
Bas-Jan Zandt
Keyword(s):  
Dendritic Morphology ◽  
Synaptic Integration

scholarly journals Active membrane conductances and morphology of a collision detection neuron broaden its impedance profile and improve membrane synchrony

2018 ◽  
Author(s):  
Richard Dewell ◽  
Fabrizio Gabbiani
Keyword(s):  
Synaptic Input ◽  
Collision Detection ◽  
Dendritic Morphology ◽  
Synaptic Integration ◽  
Neuronal Membrane ◽  
Hcn Channels ◽  
Movement Detector ◽  
Membrane Impedance ◽  
Wide Range

Brains processes information through the coordinated efforts of billions of individual neurons, each encoding a small part of the overall information stream. Central to this is how neurons integrate and transform complex patterns of synaptic inputs. The neuronal membrane impedance sets the gain and timing for synaptic integration, determining a neuron's ability to discriminate between synaptic input patterns. Using single and dual dendritic recordings in vivo, pharmacology, and computational modeling, we characterized the membrane impedance of a collision detection neuron in the grasshopper, Schistocerca americana. We examined how the cellular properties of the lobula giant movement detector (LGMD) neuron are tuned to enable the discrimination of synaptic input patterns key to its role in collision detection. We found that two common active conductances gH and gM, mediated respectively by hyperpolarization-activated cyclic nucleotide gated (HCN) channels and by muscarine sensitive M-type K+ channels, promote broadband integration with high temporal precision over the LGMD's natural range of membrane potentials and synaptic input frequencies. Additionally, we found that the LGMD's branching morphology increased the gain and decreased delays associated with the mapping of synaptic input currents to membrane potential. We investigated whether other branching dendritic morphologies fulfill a similar function and found this to be true for a wide range of morphologies, including those of neocortical pyramidal neurons and cerebellar Purkinje cells. These findings further our understanding of the integration properties of individual neurons by showing the unexpected role played by two widespread active conductances and by dendritic morphology in shaping synaptic integration.

scholarly journals Developmental emergence of two-stage nonlinear synaptic integration in cerebellar interneurons

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Celia Biane ◽  
Florian Rückerl ◽  
Therese Abrahamsson ◽  
Cécile Saint-Cloment ◽  
Jean Mariani ◽  
...  
Keyword(s):  
Dendritic Morphology ◽  
Synaptic Integration ◽  
Normal Brain ◽  
Biophysical Modeling ◽  
Cellular Mechanisms ◽  
Two Stage ◽  
Integration Model ◽  
Postnatal Maturation ◽  
Cable Properties ◽  
Neuronal Computation

Synaptic transmission, connectivity, and dendritic morphology mature in parallel during brain development and are often disrupted in neurodevelopmental disorders. Yet how these changes influence the neuronal computations necessary for normal brain function are not well understood. To identify cellular mechanisms underlying the maturation of synaptic integration in interneurons, we combined patch-clamp recordings of excitatory inputs in mouse cerebellar stellate cells (SCs), three-dimensional reconstruction of SC morphology with excitatory synapse location, and biophysical modeling. We found that postnatal maturation of postsynaptic strength was homogeneously reduced along the somatodendritic axis, but dendritic integration was always sublinear. However, dendritic branching increased without changes in synapse density, leading to a substantial gain in distal inputs. Thus, changes in synapse distribution, rather than dendrite cable properties, are the dominant mechanism underlying the maturation of neuronal computation. These mechanisms favor the emergence of a spatially compartmentalized two-stage integration model promoting location-dependent integration within dendritic subunits.

Dorsal Horn Pain Mechanisms

2019 ◽  
pp. 444-469 ◽  
Author(s):  
Hanns Ulrich Zeilhofer ◽  
Robert Ganley
Keyword(s):  
Dorsal Horn ◽  
Neuronal Excitability ◽  
Functional Organization ◽  
Synaptic Integration ◽  
Synaptic Efficacy ◽  
Pain Mechanisms ◽  
Pain Pathway ◽  
Pathological Pain ◽  
The Subject ◽  
Equivalent Structure

The spinal dorsal horn and its equivalent structure in the brainstem constitute the first sites of synaptic integration in the pain pathway. A huge body of literature exists on alterations in spinal nociceptive signal processing that contribute to the generation of exaggerated pain states and hence to what is generally known as “central sensitization.” Such mechanisms include changes in synaptic efficacy or neuronal excitability, which can be evoked by intense nociceptive stimulation or by inflammatory or neuropathic insults. Some of these changes cause alterations in the functional organization of dorsal horn sensory circuits, leading to abnormal pathological pain sensations. This article reviews the present state of this knowledge. It does not cover the contributions of astrocytes and microglia in detail as their functions are the subject of a separate chapter.

Dendritic morphology of alpha ganglion cells in the rat retina

1989 ◽  
Vol 9 ◽  
pp. 174
Author(s):  
Masaki Tauchi ◽  
Yutaka Fukuda ◽  
Katsuko Morigiwa ◽  
Kwok-Fai So
Keyword(s):  
Ganglion Cells ◽  
Dendritic Morphology ◽  
Rat Retina
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