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

Brain ◽  
2014 ◽  
Vol 137 (6) ◽  
pp. 1701-1715 ◽  
Author(s):  
Christopher A. Reid ◽  
Bryan Leaw ◽  
Kay L. Richards ◽  
Robert Richardson ◽  
Verena Wimmer ◽  
...  
Keyword(s):  
Pyramidal Neurons ◽  
Dendritic Arborization ◽  
Dravet Syndrome

scholarly journals Morphometric characteristics of Neuropeptide Y immunoreactive neurons of human cortical amygdaloid nucleus

2008 ◽  
Vol 61 (5-6) ◽  
pp. 235-241
Author(s):  
Milos Malis ◽  
Valentina Nikolic ◽  
Vuk Djulejic ◽  
Dejan Opric ◽  
Lukas Rasulic ◽  
...  
Keyword(s):  
Pyramidal Neurons ◽  
Dendritic Arborization ◽  
Amygdaloid Complex ◽  
Amygdaloid Nucleus ◽  
Morphometric Characteristics ◽  
Male Adult ◽  
Moderate Number ◽  
Triangular Shape ◽  
Nonpyramidal Neurons ◽  
Human Brains

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.

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

2003 ◽  
Vol 89 (6) ◽  
pp. 3143-3154 ◽  
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.

scholarly journals Early hippocampal hyperexcitability followed by disinhibition in a mouse model of Dravet syndrome

2019 ◽  
Author(s):  
Yael Almog ◽  
Marina Brusel ◽  
Karen Anderson ◽  
Moran Rubinstein
Keyword(s):  
Pyramidal Neurons ◽  
Febrile Seizures ◽  
Cell Types ◽  
Dravet Syndrome ◽  
Inhibitory Neurons ◽  
Temporary Increase ◽  
Ca1 Pyramidal Neurons ◽  
Spontaneous Seizures ◽  
Hippocampal Ca1 ◽  
Firing Properties

AbstractDravet syndrome (Dravet) epilepsy begins with febrile seizures followed by worsening to refractory seizures, with some improvement and stabilization toward adolescence. The neuronal basis of Dravet is debatable, with evidence favoring reduced inhibition or enhanced excitation. Focusing on the firing properties of hippocampal CA1 pyramidal neurons and oriens-lacunosum moleculare (O-LM) interneurons, we provide a comprehensive analysis of the activity of both cell types through the febrile, worsening and stabilization stages. Our data indicate a temporary increase in the excitability of CA1 pyramidal neurons during the febrile stage, which is fully reversed by the onset of spontaneous seizures. In contrast, reduced function of O-LM interneurons persisted from the febrile through the stabilization stages, with the greatest impairment of excitability occurring during the worsening stage. Thus, both excitatory and inhibitory neurons contribute to Dravet, indicating complex and reciprocal pathophysiological neuronal changes during the different stages of the disease.Graphical abstract

scholarly journals Sez-6 Proteins Affect Dendritic Arborization Patterns and Excitability of Cortical Pyramidal Neurons

Neuron ◽  
2007 ◽  
Vol 56 (4) ◽  
pp. 621-639 ◽  
Author(s):  
Jenny M. Gunnersen ◽  
Mary H. Kim ◽  
Stephanie J. Fuller ◽  
Melanie De Silva ◽  
Joanne M. Britto ◽  
...  
Keyword(s):  
Pyramidal Neurons ◽  
Dendritic Arborization ◽  
Cortical Pyramidal Neurons

scholarly journals Iron Deficiency and Iron Excess Alter Dendritic Architecture of Pyramidal Neurons in the Hippocampus of Neonatal Pigs

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1232-1232
Author(s):  
Vivian Perng ◽  
Chong Li ◽  
Shya Navazesh ◽  
Carolyn Klocke ◽  
Danna Pinneles ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Iron Homeostasis ◽  
Pyramidal Neurons ◽  
Iron Status ◽  
Transferrin Saturation ◽  
Dendritic Arborization ◽  
Sholl Analysis ◽  
Iron Deficient ◽  
Gene And Protein Expression ◽  
Significant Difference

Abstract Objectives The study assessed effect of dietary iron on iron homeostasis and dendritic architecture of hippocampal neurons in young piglets. Methods On postnatal day (PD) 1, 30 piglets (15 male/female) were blocked by sex and randomized to treatments by receiving no (N), low (L) or high (H) dose of iron supplement during pre- (PD1–21) and post-weaning period (PD22–35). Pigs in N, L, and H group orally received 0, 1, and 30 mg iron/(kg BW· d) as ferrous sulfate solution pre-weaning and were fed a solid diet containing 30, 125, and 1000 mg iron/kg post-weaning, respectively. Blood samples were collected on PD1 and weekly thereafter to analyze iron biomarkers. Iron homeostasis in hippocampus was assessed by measuring gene and protein expression of iron transporters. Hippocampal neurons stained with Golgi-Cox method were traced and 3D reconstructed using Neurolucida. Dendritic arborization were quantified through Sholl analysis and Neurolucida Explorer. Results Pigs in H group had the highest growth rate, whereas N pigs displayed growth retardation from PD27 to PD35, resulting in significant difference in body weight compared to H group (P &lt; 0.05). Iron dose-dependently increased hemoglobin (Hb), hematocrit, plasma iron and transferrin saturation since PD7 or PD14 (P &lt; 0.05). Pigs in N group became iron deficient since PD14 (Hb &lt; 11 g/dL). Similarly, hippocampal ferritin expression was upregulated with the increase of iron (P &lt; 0.05). The mRNA expression of TFRC and DMT1 in hippocampus was highest in N and lowest in H group (P &lt; 0.05). Despite relatively low abundance, HAMP expression tended to be higher in H than that in N (P &lt; 0.10). Sholl analysis uncovered significant main effect of treatment on basilar dendritic arborization of CA1 and CA3 pyramidal neurons (P ≤ 0.04). There were less branching nodes and dendrites in N than in H group (P &lt; 0.05). However, the difference in dendritic arborization was primarily derived from the higher order (&gt; 3) of branches in both regions. Iron supplementation did not affect architecture of apical dendrites of granule cells in dentate gyrus. Conclusions Early-life iron status affects hippocampal iron homeostasis and alters development of pyramidal neurons in a piglet model. Funding Sources NIFA Hatch/Multistate Research Fund.

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

2016 ◽  
Vol 36 (9) ◽  
pp. 2723-2742 ◽  
Author(s):  
Minhan Ka ◽  
Divyan A. Chopra ◽  
Shashank M. Dravid ◽  
Woo-Yang Kim
Keyword(s):  
Pyramidal Neurons ◽  
Dendritic Arborization ◽  
Spine Morphology

scholarly journals Fractal analysis of dendritic arborization patterns of pyramidal neurons in human basolateral amygdala

2008 ◽  
Vol 7 (S1) ◽  
Author(s):  
Jovo Tosevski ◽  
Predrag Sazdanovic ◽  
Ivana Zivanovic-Macuzic ◽  
Maja Stankovic Vulovic ◽  
Dejan Jeremic ◽  
...  
Keyword(s):  
Fractal Analysis ◽  
Basolateral Amygdala ◽  
Pyramidal Neurons ◽  
Dendritic Arborization

scholarly journals Pyramidal cell morphology and cell death in the hippocampus of adult mice with experimentally induced hydrocephalus

2020 ◽  
Vol 47 (4) ◽  
pp. 298-304
Author(s):  
M.T. Shokunbi ◽  
F.E. Olopade ◽  
O.M. Femi-Akinlosotu ◽  
E.O. Ajiboye
Keyword(s):  
Pyramidal Cell ◽  
Pyramidal Neurons ◽  
Pyramidal Cells ◽  
Dendritic Arborization ◽  
Adult Onset ◽  
Neural Structure ◽  
Post Induction ◽  
Ca1 Region ◽  
And Control ◽  
Ca3 Region

Background: Hippocampus is a neural structure in the temporal lobe that plays a crucial role in learning and memory. Cognitive impairment with learning disabilities is a common feature in hydrocephalus and is more prominent in adult-onset hydrocephalus. The aim of this study is to describethe morphological alterations in the pyramidal cells of the hippocampus of adult hydrocephalic mice. Method: Hydrocephalus was induced in adult albino mice by intra-cisternal injection of kaolin suspension (250 mg/ml in sterile water). They were  sacrificed 7, 14 and 21 days post-induction. Morphological analysis was carried out on hematoxylin and eosinstained coronal sections of the  hippocampus: the pyramidal neurons (normal and pyknotic) in the CA1 and CA3 subregions were counted and the pyknotic index (PI) was  calculated. The somatic and dendritic features of Golgistained pyramidal neurons were examined by light microscopy in both hydrocephalic and control mice. Result: The PI was significantly greater in the CA1 region of the hippocampus in the hydrocephalic groups compared to the agematched controls. The dendritic processes of pyramidal neurons in the CA1 region were fewer with shorter terminal branches in the hydrocephalic mice than in  controls; this was pronounced at 7 days post-induction. In the CA3 region, there was no difference in dendritic arborization between hydrocephalic and control mice. Conclusion: Acute adult-onset hydrocephalus was associated with increased pyknosis and reduced dendritic arborization in hippocampal pyramidal cells in the CA1 but not CA3 region. Keywords: Hippocampal pyramidal cell, Hydrocephalus, Pyknotic index, Golgi stain

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