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.

Heterogeneity of Phasic Cholinergic Signaling in Neocortical Neurons

2007 ◽  
Vol 97 (3) ◽  
pp. 2215-2229 ◽  
Author(s):  
Allan T. Gulledge ◽  
Susanna B. Park ◽  
Yasuo Kawaguchi ◽  
Greg J. Stuart
Keyword(s):  
Visual Cortex ◽  
Calcium Release ◽  
Pyramidal Neurons ◽  
Potassium Conductance ◽  
Projection Neurons ◽  
Sk Channels ◽  
Cortical Areas ◽  
Neocortical Neurons ◽  
Cholinergic Signaling ◽  
Nonpyramidal Neurons

Acetylcholine (ACh) is a neurotransmitter critical for normal cognition. Here we demonstrate heterogeneity of cholinergic signaling in neocortical neurons in the rat prefrontal, somatosensory, and visual cortex. Focal ACh application (100 μM) inhibited layer 5 pyramidal neurons in all cortical areas via activation of an apamin-sensitive SK-type calcium-activated potassium conductance. Cholinergic inhibition was most robust in prefrontal layer 5 neurons, where it relies on the same signal transduction mechanism (M1-like receptors, IP3-dependent calcium release, and SK-channels) as exists in somatosensory pyramidal neurons. Pyramidal neurons in layer 2/3 were less responsive to ACh, but substantial apamin-sensitive inhibitory responses occurred in deep layer 3 neurons of the visual cortex. ACh was only inhibitory when presented near the somata of layer 5 pyramidal neurons, where repetitive ACh applications generated discrete inhibitory events at frequencies of up to ∼0.5 Hz. Fast-spiking (FS) nonpyramidal neurons in all cortical areas were unresponsive to ACh. When applied to non-FS interneurons in layers 2/3 and 5, ACh generated mecamylamine-sensitive nicotinic responses (38% of cells), apamin-insensitive hyperpolarizing responses, with or without initial nicotinic depolarization (7% of neurons), or no response at all (55% of cells). Responses in interneurons were similar across cortical layers and regions but were correlated with cellular physiology and the expression of biochemical markers associated with different classes of nonpyramidal neurons. Finally, ACh generated nicotinic responses in all layer 1 neurons tested. These data demonstrate that phasic cholinergic input can directly inhibit projection neurons throughout the cortex while sculpting intracortical processing, especially in superficial layers.

scholarly journals Glutamatergic Nonpyramidal Neurons From Neocortical Layer VI and Their Comparison With Pyramidal and Spiny Stellate Neurons

2009 ◽  
Vol 101 (2) ◽  
pp. 641-654 ◽  
Author(s):  
Sofija Andjelic ◽  
Thierry Gallopin ◽  
Bruno Cauli ◽  
Elisa L. Hill ◽  
Lisa Roux ◽  
...  
Keyword(s):  
Pyramidal Neurons ◽  
Glutamate Transporter ◽  
Gabaergic Interneuron ◽  
Acid Decarboxylase ◽  
Projection Neurons ◽  
Heterogeneous Cluster ◽  
Glutamatergic Neurons ◽  
Layer V ◽  
Nonpyramidal Neurons ◽  
Layer Vi

The deeper part of neocortical layer VI is dominated by nonpyramidal neurons, which lack a prominent vertically ascending dendrite and predominantly establish corticocortical connections. These neurons were studied in rat neocortical slices using patch-clamp, single-cell reverse transcription–polymerase chain reaction, and biocytin labeling. The majority of these neurons expressed the vesicular glutamate transporter but not glutamic acid decarboxylase, suggesting that a high proportion of layer VI nonpyramidal neurons are glutamatergic. Indeed, they exhibited numerous dendritic spines and established asymmetrical synapses. Our sample of glutamatergic nonpyramidal neurons displayed a wide variety of somatodendritic morphologies and a subset of these cells expressed the Nurr1 mRNA, a marker for ipsilateral, but not commissural corticocortical projection neurons in layer VI. Comparison with spiny stellate and pyramidal neurons from other layers showed that glutamatergic neurons consistently exhibited a low occurrence of GABAergic interneuron markers and regular spiking firing patterns. Analysis of electrophysiological diversity using unsupervised clustering disclosed three groups of cells. Layer V pyramidal neurons were segregated into a first group, whereas a second group consisted of a subpopulation of layer VI neurons exhibiting tonic firing. A third heterogeneous cluster comprised spiny stellate, layer II/III pyramidal, and layer VI neurons exhibiting adaptive firing. The segregation of layer VI neurons in two different clusters did not correlate either with their somatodendritic morphologies or with Nurr1 expression. Our results suggest that electrophysiological similarities between neocortical glutamatergic neurons extend beyond layer positioning, somatodendritic morphology, and projection specificity.

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 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 Unique inhibitory synapse with particularly rich endocannabinoid signaling machinery on pyramidal neurons in basal amygdaloid nucleus

2011 ◽  
Vol 108 (7) ◽  
pp. 3059-3064 ◽  
Author(s):  
T. Yoshida ◽  
M. Uchigashima ◽  
M. Yamasaki ◽  
I. Katona ◽  
M. Yamazaki ◽  
...  
Keyword(s):  
Pyramidal Neurons ◽  
Inhibitory Synapse ◽  
Amygdaloid Nucleus

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.

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