Essential Roles for ARID1B in Dendritic Arborization and Spine Morphology of Developing Pyramidal Neurons

Introduction Cortical amygdaloid nucleus belongs to the corticomedial part of the amygdaloid complex. In this nucleus there are neurons that produce neuropetide Y. This peptide has important roles in sleeping, learning, memory, gastrointestinal regulation, anxiety, epilepsy, alcoholism and depression. Material and methods We investigated morphometric characteristics (numbers of primary dendrites, longer and shorter diameters of cell bodies and maximal radius of dendritic arborization) of NPY immunoreactive neurons of human cortical amygdaloid nucleus on 6 male adult human brains, aged 46 to 77 years, by immunohistochemical avidin-biotin technique. Results Our investigation has shown that in this nucleus there is a moderate number of NPY immunoreactive neurons. 67% of found neurons were nonpyramidal, while 33% were pyramidal. Among the nonpyramidal neurons the dominant groups were multipolar neurons (41% - of which 25% were multipolar irregular, and 16% multipolar oval). Among the pyramidal neurons the dominant groups were the neurons with triangular shape of cell body (21%). All found NPY immunoreactive neurons (pyramidal and nonpyramidal altogether) had intervals of values of numbers of primary dendrites 2 to 6, longer diameters of cell bodies 13 to 38 ?m, shorter diameters of cell bodies 9 to 20 ?m and maximal radius of dendritic arborization 50 to 340 ?m. More than a half of investigated neurons (57%) had 3 primary dendrites. Discussion and conclusion The other researchers did not find such percentage of pyramidal immunoreactive neurons in this amygdaloid nucleus. If we compare our results with the results of the ather researchers we can conclude that all pyramidal NPY immunoreactive neurons found in this human amygdaloid nucleus belong to the class I of neurons, and that all nonpyramidal NPY immunoreactive neurons belong to the class II of neurons described by other researchers. We suppose that all found pyramidal neurons were projectional.

Download Full-text

Basolateral Amygdala α1-Adrenergic Receptor Suppression Attenuates Stress-Induced Anxiety-Like Behavior and Spine Morphology Impairment on Hippocampal CA1 Pyramidal Neurons

Neurochemical Journal ◽

10.1134/s1819712420010079 ◽

2020 ◽

Vol 14 (1) ◽

pp. 77-89 ◽

Cited By ~ 1

Author(s):

Nasrin Faraji ◽

Abdolhossein Shiravi ◽

Zahra Bahari ◽

Hossein Shirvani ◽

Gholam Hossein Meftahi

Keyword(s):

Adrenergic Receptor ◽

Basolateral Amygdala ◽

Pyramidal Neurons ◽

Spine Morphology ◽

Ca1 Pyramidal Neurons ◽

Hippocampal Ca1

Download Full-text

Impact of JNK and Its Substrates on Dendritic Spine Morphology

Cells ◽

10.3390/cells9020440 ◽

2020 ◽

Vol 9 (2) ◽

pp. 440 ◽

Cited By ~ 2

Author(s):

Emilia Komulainen ◽

Artemis Varidaki ◽

Natalia Kulesskaya ◽

Hasan Mohammad ◽

Christel Sourander ◽

...

Keyword(s):

Dendritic Spine ◽

Pyramidal Neurons ◽

Lucifer Yellow ◽

Dendrite Morphology ◽

Spine Morphology ◽

Kinase Substrate ◽

Basal Dendrites ◽

Dendritic Spine Morphology ◽

Mushroom Spines

The protein kinase JNK1 exhibits high activity in the developing brain, where it regulates dendrite morphology through the phosphorylation of cytoskeletal regulatory proteins. JNK1 also phosphorylates dendritic spine proteins, and Jnk1-/- mice display a long-term depression deficit. Whether JNK1 or other JNKs regulate spine morphology is thus of interest. Here, we characterize dendritic spine morphology in hippocampus of mice lacking Jnk1-/- using Lucifer yellow labelling. We find that mushroom spines decrease and thin spines increase in apical dendrites of CA3 pyramidal neurons with no spine changes in basal dendrites or in CA1. Consistent with this spine deficit, Jnk1-/- mice display impaired acquisition learning in the Morris water maze. In hippocampal cultures, we show that cytosolic but not nuclear JNK, regulates spine morphology and expression of phosphomimicry variants of JNK substrates doublecortin (DCX) or myristoylated alanine-rich C kinase substrate-like protein-1 (MARCKSL1), rescue mushroom, thin, and stubby spines differentially. These data suggest that physiologically active JNK controls the equilibrium between mushroom, thin, and stubby spines via phosphorylation of distinct substrates.

Download Full-text

Reduced dendritic arborization and hyperexcitability of pyramidal neurons in a Scn1b-based model of Dravet syndrome

Brain ◽

10.1093/brain/awu077 ◽

2014 ◽

Vol 137 (6) ◽

pp. 1701-1715 ◽

Cited By ~ 25

Author(s):

Christopher A. Reid ◽

Bryan Leaw ◽

Kay L. Richards ◽

Robert Richardson ◽

Verena Wimmer ◽

...

Keyword(s):

Pyramidal Neurons ◽

Dendritic Arborization ◽

Dravet Syndrome

Download Full-text

Coincidence Detection in Pyramidal Neurons Is Tuned by Their Dendritic Branching Pattern

Journal of Neurophysiology ◽

10.1152/jn.00046.2003 ◽

2003 ◽

Vol 89 (6) ◽

pp. 3143-3154 ◽

Cited By ~ 171

Author(s):

Andreas T. Schaefer ◽

Matthew E. Larkum ◽

Bert Sakmann ◽

Arnd Roth

Keyword(s):

Pyramidal Neurons ◽

Experimental Studies ◽

Brain Slices ◽

Apical Dendrite ◽

Dendritic Arborization ◽

Coincidence Detection ◽

Membrane Properties ◽

Relative Reduction ◽

Close Proximity ◽

The Relationship

Neurons display a variety of complex dendritic morphologies even within the same class. We examined the relationship between dendritic arborization and the coupling between somatic and dendritic action potential (AP) initiation sites in layer 5 (L5) neocortical pyramidal neurons. Coupling was defined as the relative reduction in threshold for initiation of a dendritic calcium AP due to a coincident back-propagating AP. Simulations based on reconstructions of biocytin-filled cells showed that addition of oblique branches of the main apical dendrite in close proximity to the soma ( d < 140 μm) increases the coupling between the apical and axosomatic AP initiation zones, whereas incorporation of distal branches decreases coupling. Experimental studies on L5 pyramids in acute brain slices revealed a highly significant ( n = 28, r = 0.63, P < 0.0005) correlation: increasing the fraction of proximal oblique dendrites ( d < 140 μm), e.g., from 30 to 60% resulted on average in an increase of the coupling from approximately 35% to almost 60%. We conclude that variation in dendritic arborization may be a key determinant of variability in coupling (49 ± 17%; range 19–83%; n = 37) and is likely to outweigh the contribution made by variations in active membrane properties. Thus coincidence detection of inputs arriving from different cortical layers is strongly regulated by differences in dendritic arborization.

Download Full-text

Conditional deletion of ROCK2 induces anxiety-like behaviors and alters dendritic spine density and morphology on CA1 pyramidal neurons

Molecular Brain ◽

10.1186/s13041-021-00878-4 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Audrey J. Weber ◽

Ashley B. Adamson ◽

Kelsey M. Greathouse ◽

Julia P. Andrade ◽

Cameron D. Freeman ◽

...

Keyword(s):

Dendritic Spine ◽

Basolateral Amygdala ◽

Pyramidal Neurons ◽

Pyramidal Cells ◽

Spine Density ◽

Control Of Gene Expression ◽

Spine Morphology ◽

Dendritic Spine Morphology ◽

Morphometry Analysis ◽

Apical Dendrites

AbstractRho-associated kinase isoform 2 (ROCK2) is an attractive drug target for several neurologic disorders. A critical barrier to ROCK2-based research and therapeutics is the lack of a mouse model that enables investigation of ROCK2 with spatial and temporal control of gene expression. To overcome this, we generated ROCK2fl/fl mice. Mice expressing Cre recombinase in forebrain excitatory neurons (CaMKII-Cre) were crossed with ROCK2fl/fl mice (Cre/ROCK2fl/fl), and the contribution of ROCK2 in behavior as well as dendritic spine morphology in the hippocampus, medial prefrontal cortex (mPFC), and basolateral amygdala (BLA) was examined. Cre/ROCK2fl/fl mice spent reduced time in the open arms of the elevated plus maze and increased time in the dark of the light–dark box test compared to littermate controls. These results indicated that Cre/ROCK2fl/fl mice exhibited anxiety-like behaviors. To examine dendritic spine morphology, individual pyramidal neurons in CA1 hippocampus, mPFC, and the BLA were targeted for iontophoretic microinjection of fluorescent dye, followed by high-resolution confocal microscopy and neuronal 3D reconstructions for morphometry analysis. In dorsal CA1, Cre/ROCK2fl/fl mice displayed significantly increased thin spine density on basal dendrites and reduced mean spine head volume across all spine types on apical dendrites. In ventral CA1, Cre/ROCK2fl/fl mice exhibited significantly increased spine length on apical dendrites. Spine density and morphology were comparable in the mPFC and BLA between both genotypes. These findings suggest that neuronal ROCK2 mediates spine density and morphology in a compartmentalized manner among CA1 pyramidal cells, and that in the absence of ROCK2 these mechanisms may contribute to anxiety-like behaviors.

Download Full-text

Role of Dendritic Spines in Action Potential Backpropagation: A Numerical Simulation Study

Journal of Neurophysiology ◽

10.1152/jn.00781.2001 ◽

2002 ◽

Vol 88 (5) ◽

pp. 2834-2845 ◽

Cited By ~ 21

Author(s):

David Tsay ◽

Rafael Yuste

Keyword(s):

Action Potential ◽

Sodium Channels ◽

Dendritic Spines ◽

Pyramidal Neurons ◽

Excitatory Input ◽

Spine Morphology ◽

Dendritic Shaft ◽

Apical Dendrites ◽

Channel Properties

Two remarkable aspects of pyramidal neurons are their complex dendritic morphologies and the abundant presence of spines, small structures that are the sites of excitatory input. Although the channel properties of the dendritic shaft membrane have been experimentally probed, the influence of spine properties in dendritic signaling and action potential propagation remains unclear. To explore this we have performed multi-compartmental numerical simulations investigating the degree of consistency between experimental data on dendritic channel densities and backpropagation behavior, as well as the necessity and degree of influence of excitable spines. Our results indicate that measured densities of Na+ channels in dendritic shafts cannot support effective backpropagation observed in apical dendrites due to suprathreshold inactivation. We demonstrate as a potential solution that Na+ channels in spines at higher densities than those measured in the dendritic shaft can support extensive backpropagation. In addition, clustering of Na+ channels in spines appears to enhance their effect due to their unique morphology. Finally, we show that changes in spine morphology significantly influence backpropagation efficacy. These results suggest that, by clustering sodium channels, spines may serve to control backpropagation.

Download Full-text