Course and distribution of apical dendrites of layer V pyramids in the barrel field and area parietalis of the mouse

Numerous lines of evidence indicate that neural information is exchanged between the cerebral hemispheres via the corpus callosum. Unilateral ablation lesions of barrel field cortex (BFC) in adult rats induce strong suppression of background and evoked activity in the contralateral barrel cortex and significantly delay the onset of experience-dependent plasticity. The present experiments were designed to clarify the basis for these interhemispheric effects. One possibility is that degenerative events, triggered by the lesion, degrade contralateral cortical function. Another hypothesis, alone or in combination with degeneration, is that the absence of interhemispheric activity after the lesion suppresses contralateral responsiveness. The latter hypothesis was tested by placing an Alzet minipump subcutaneously and connecting it via a delivery tube to a cannula implanted over BFC. The minipump released muscimol, a GABAA receptor agonist at a rate of 1 μl/h, onto one barrel field cortex for 7 days. Then with the pump still in place, single cells were recorded in the contralateral BFC under urethan anesthesia. The data show a ∼50% reduction in principal whisker responses (D2) compared with controls, with similar reductions in responses to the D1 and D3 surround whiskers. Despite these reductions, spontaneous firing is unaffected. Fast spiking units are more sensitive to muscimol application than regular spiking units in both the response magnitude and the center/surround ratio. Effects of muscimol are also layer specific. Layer II/III and layer IV neurons decrease their responses significantly, unlike layer V neurons that fail to show significant deficits. The results indicate that reduced activity in one hemisphere alters cortical excitability in the other hemisphere in a complex manner. Surprisingly, a prominent response decrement occurs in the short-latency (3–10 ms) component of principal whisker responses, suggesting that suppression may spread to neurons dominated by thalamocortical inputs after interhemispheric connections are inactivated. Bilateral neurological impairments have been described after unilateral stroke lesions in the clinical literature.

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Differential modulatory effects of norepinephrine on synaptically driven responses of layer V barrel field cortical neurons

Brain Research ◽

10.1016/s0006-8993(00)02261-7 ◽

2000 ◽

Vol 868 (1) ◽

pp. 39-47 ◽

Cited By ~ 29

Author(s):

Barry D. Waterhouse ◽

Robert Mouradian ◽

Francis M. Sessler ◽

Rick C.S. Lin

Keyword(s):

Cortical Neurons ◽

Barrel Field ◽

Layer V

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Spatiotemporally differential inhibition of pyramidal cells in the cat motor cortex

Journal of Neurophysiology ◽

10.1152/jn.1994.71.1.280 ◽

1994 ◽

Vol 71 (1) ◽

pp. 280-293 ◽

Cited By ~ 58

Author(s):

Y. Kang ◽

T. Kaneko ◽

H. Ohishi ◽

K. Endo ◽

T. Araki

Keyword(s):

Motor Cortex ◽

Rise Time ◽

Pyramidal Cells ◽

Spatiotemporal Pattern ◽

Stimulation Site ◽

Time To Peak ◽

Early Portion ◽

Layer V ◽

Apical Dendrites ◽

Stimulation Of

1. The spatiotemporal pattern of inhibition in the cat motor cortex was studied in in vitro slice preparations in the presence of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and 2-amino-5-phosphonovaleric acid (APV). 2. After intracortical microstimulation (0.5–6 microA), fast and slow inhibitory postsynaptic potentials (IPSPs) were produced in layers II–VI pyramidal cells and selectively reduced with bicuculline methiodide and phaclofen, respectively. 3. Fast IPSPs were maximally produced by stimulation of the same layer where their cell bodies were located, and they decreased in amplitude as the more superficial layer was stimulated. In contrast, slow IPSPs were maximally produced by stimulation of layer II regardless of the location of the recorded pyramidal cell and decreased in amplitude as the deeper layer was stimulated. 4. The reduction of amplitude of fast IPSPs, in response to a vertical shift of the stimulation site toward more superficial layers, was always correlated with an increase in rise time and with a shift of the reversal potential to a more hyperpolarized level. 5. When the stimulation site was moved horizontally to the more lateral site, fast IPSPs increased in latency and decreased in amplitude gradually without appreciable changes in rise time. Fast IPSPs could be evoked from horizontally remote sites of up to 800–1,200 microns. 6. Inhibitory interneurons, which are responsible for evoking fast IPSPs, appear to be distributed through almost all layers to send horizontally spreading parallel axons making synaptic contacts at different electrotonic distances along apical dendrites of single pyramidal cells. 7. Horizontal spreads were much less in slow IPSPs (< 340–680 microns). The time-to-peak of slow IPSPs produced in layer V pyramidal cells (159.5 +/- 6.8 ms, mean +/- SD, n = 10) was significantly (P < 0.0001) longer than that in layers II and III pyramidal cells (128.5 +/- 7.5 ms, n = 7). Asymmetric reversal properties of slow IPSPs were seen, suggesting the spatial dispersion of synaptic inputs along apical dendrites of pyramidal cells. 8. In layer V pyramidal cells, the time-to-peak of slow IPSPs decreased with increasing membrane hyperpolarization, indicating that the later portion of slow IPSPs was more sensitive to the membrane-potential change than the early portion. This further indicates that the late portion of slow IPSPs is generated at synapses on the more proximal dendrite of pyramidal cells than the early portion, contrary to that expected from the Rall's model of passive dendrite under the condition of synchronous inputs.(ABSTRACT TRUNCATED AT 400 WORDS)

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Glutamate Receptors Form Hot Spots on Apical Dendrites of Neocortical Pyramidal Neurons

Journal of Neurophysiology ◽

10.1152/jn.2001.86.3.1412 ◽

2001 ◽

Vol 86 (3) ◽

pp. 1412-1421 ◽

Cited By ~ 23

Author(s):

A. Frick ◽

W. Zieglgänsberger ◽

H.-U. Dodt

Keyword(s):

Glutamate Receptors ◽

Hot Spots ◽

Pyramidal Neurons ◽

Flash Photolysis ◽

Apical Dendrite ◽

Brain Regions ◽

Branch Points ◽

Cortical Pyramidal Neurons ◽

Layer V ◽

Apical Dendrites

Apical dendrites of layer V cortical pyramidal neurons are a major target for glutamatergic synaptic inputs from cortical and subcortical brain regions. Because innervation from these regions is somewhat laminar along the dendrites, knowing the distribution of glutamate receptors on the apical dendrites is of prime importance for understanding the function of neural circuits in the neocortex. To examine this issue, we used infrared-guided laser stimulation combined with whole cell recordings to quantify the spatial distribution of glutamate receptors along the apical dendrites of layer V pyramidal neurons. Focally applied (<10 μm) flash photolysis of caged glutamate on the soma and along the apical dendrite revealed a highly nonuniform distribution of glutamate responsivity. Up to four membrane areas (extent 22 μm) of enhanced glutamate responsivity (hot spots) were detected on the dendrites with the amplitude and integral of glutamate-evoked responses at hot spots being three times larger than responses evoked at neighboring sites. We found no association of these physiological hot spots with dendritic branch points. It appeared that the larger responses evoked at hot spots resulted from an increase in activation of both α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-d-aspartate (NMDA) receptors and not a recruitment of voltage-activated sodium or calcium conductances. Stimulation of hot spots did, however, facilitate the triggering of both Na+ spikes and Ca2+ spikes, suggesting that hot spots may serve as dendritic initiation zones for regenerative spikes.

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Electrophysiological and morphological characteristics of layer VI pyramidal cells in the cat motor cortex

Journal of Neurophysiology ◽

10.1152/jn.1994.72.2.578 ◽

1994 ◽

Vol 72 (2) ◽

pp. 578-591 ◽

Cited By ~ 36

Author(s):

Y. Kang ◽

F. Kayano

Keyword(s):

Motor Cortex ◽

Action Potentials ◽

Morphological Characteristics ◽

Pyramidal Cells ◽

Apical Dendrite ◽

Current Pulses ◽

Axon Collaterals ◽

Layer V ◽

Apical Dendrites ◽

Layer Vi

1. Intracellular recordings were made from layer VI pyramidal cells in in vitro slice preparations of the cat motor cortex (area 4 gamma). Layer VI pyramidal cells were identified morphologically by intracellular injection of biocytin. 2. Of 22 layer VI pyramidal cells examined, single action potentials were followed by depolarizing afterpotentials (DAP) in 9 cells, but were not followed by DAP in the remaining 13 cells. The amplitude of DAP was 3.4 +/- 1.4 mV (mean +/- SD, n = 9) when measured from the negative peak of fast afterhyperpolarization to the peak of DAP. 3. In response to depolarizing current pulses with a duration of 300–400 ms, pyramidal cells showing DAP displayed a train of action potentials in a phasic-tonic pattern without any appreciable adaptation in the tonic firing, whereas pyramidal cells lacking DAP exhibited a weak adaptation after phasic firing. Anomalous rectification was seen in both pyramidal cells showing DAP and those lacking DAP. 4. Repetitive doublet or triplet spiking was induced in DAP-showing pyramidal cells in response to a depolarizing current pulse after injecting strong depolarizing current pulses of 400 ms duration at 1 Hz for 30–60 s, but was never induced in DAP-lacking pyramidal cells. Doublet/triplet spiking lasted 5–10 min and returned to the original single spiking. An application of CsCl induced a burst firing in DAP-showing pyramidal cells. 5. In the nine pyramidal cells showing DAP, seven cells had shorter apical dendrites that arborized extensively at layer V and terminated in the middle part of layer III. In the 13 pyramidal cells lacking DAP, 11 cells had longer apical dendrites that arborized less frequently and extended into layer II or I. Main axons could be traced into the deep white matter in 17 of the 22 layer VI pyramidal cells examined. 6. Ascending recurrent axon collaterals were more prominent in pyramidal cells with longer apical dendrites than in pyramidal cells with shorter apical dendrites. The terminal bouton-like swelling observed along the recurrent axon collaterals arising from the pyramidal cells with longer apical dendrite were distributed most densely at the level between the bottom part of layer III and the top part of layer V. In contrast, those arising from the pyramidal cells with shorter apical dendrite were distributed mainly at the levels of layers V and VI.(ABSTRACT TRUNCATED AT 400 WORDS)

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Differential Pattern of Interhemispheric Connections Between Homotopic Layer V Regions in the Forelimb Representation in Rat Barrel Field Cortex

The Anatomical Record ◽

10.1002/ar.23262 ◽

2015 ◽

Vol 298 (11) ◽

pp. 1885-1902 ◽

Cited By ~ 2

Author(s):

Tina M. Decosta-Fortune ◽

Cheng X. Li ◽

Amy L. de Jongh Curry ◽

Robert S. Waters

Keyword(s):

Barrel Field ◽

Differential Pattern ◽

Layer V

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Oligodendrocytes in Developing Hameter Cerebral Cortex

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090610 ◽

1976 ◽

Vol 34 ◽

pp. 126-127

Author(s):

MB. Tank Buschmann

Keyword(s):

Cerebral Cortex ◽

Optic Nerve ◽

Frontal Cortex ◽

Osmium Tetroxide ◽

Sodium Cacodylate Buffer ◽

Sodium Cacodylate ◽

Tissue Samples ◽

Cacodylate Buffer ◽

Layer V ◽

Adult Hamster

Development of oligodendrocytes in rat corpus callosum was described as a sequential change in cytoplasmic density which progressed from light to medium to dark (1). In rat optic nerve, changes in cytoplasmic density were not observed, but significant changes in morphology occurred just prior to and during myelination (2). In our study, the ultrastructural development of oligodendrocytes was studied in newborn, 5-, 10-, 15-, 20-day and adult frontal cortex of the golden hamster (Mesocricetus auratus).Young and adult hamster brains were perfused with paraformaldehyde-glutaraldehyde in sodium cacodylate buffer at pH 7.3 according to the method of Peters (3). Tissue samples of layer V of the frontal cortex were post-fixed in 2% osmium tetroxide, dehydrated in acetone and embedded in Epon-Araldite resin.

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Faculty Opinions recommendation of The effects of tonic locus ceruleus output on sensory-evoked responses of ventral posterior medial thalamic and barrel field cortical neurons in the awake rat.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1022940.264694 ◽

2004 ◽

Author(s):

Gary Aston-Jones

Keyword(s):

Cortical Neurons ◽

Locus Ceruleus ◽

Evoked Responses ◽

Barrel Field ◽

Awake Rat ◽

Sensory Evoked

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Eastern Europe’s “Transitional Industry”?: Deconstructing the Early Streletskian

Journal of Paleolithic Archaeology ◽

10.1007/s41982-021-00076-7 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

R. Dinnis ◽

A. Bessudnov ◽

N. Reynolds ◽

T. Devièse ◽

A. Dudin ◽

...

Keyword(s):

Modern Human ◽

East European Plain ◽

Upper Palaeolithic ◽

Radiocarbon Dates ◽

East European ◽

Archaeological Material ◽

Younger Age ◽

Layer V ◽

Precise Relationship ◽

Early Upper

AbstractThe Streletskian is central to understanding the onset of the Upper Palaeolithic on the East European Plain. Early Streletskian assemblages are frequently seen as marking the Neanderthal-anatomically modern human (AMH) anthropological transition, as well as the Middle-to-Upper Palaeolithic archaeological transition. The age of key Streletskian assemblages, however, remains unclear, and there are outstanding questions over how they relate to Middle and Early Upper Palaeolithic facies. The three oldest Streletskian layers—Kostenki 1 Layer V, Kostenki 6 and Kostenki 12 Layer III—were excavated by A. N. Rogachev in the mid-20th century. Here, we re-examine these layers in light of problems noted during Rogachev’s campaigns and later excavations. Layer V in the northern part of Kostenki 1 is the most likely assemblage to be unmixed. A new radiocarbon date of 35,100 ± 500 BP (OxA- X-2717-21) for this assemblage agrees with Rogachev’s stratigraphic interpretation and contradicts later claims of a younger age. More ancient radiocarbon dates for Kostenki 1 Layer V are from areas lacking diagnostic Streletskian points. The Kostenki 6 assemblage’s stratigraphic context is extremely poor, but new radiocarbon dates are consistent with Rogachev’s view that the archaeological material was deposited prior to the CI tephra (i.e. >34.3 ka BP). Multiple lines of evidence indicate that Kostenki 12 Layer III contains material of different ages. Despite some uncertainty over the precise relationship between the dated sample and diagnostic lithic material, Kostenki 1 Layer V (North) therefore currently provides the best age estimate for an early Streletskian context. This age is younger than fully Upper Palaeolithic assemblages elsewhere at Kostenki. Other “Streletskian” assemblages and Streletskian points from younger contexts at Kostenki are briefly reviewed, with possible explanations for their chronostratigraphic distribution considered. We caution that the cultural taxon Streletskian should not be applied to assemblages based simply on the presence of bifacially worked artefacts.

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