Network Mechanisms of Spindle-Burst Oscillations in the Neonatal Rat Barrel Cortex In Vivo

Early in development, cortical networks generate particular patterns of activity that participate in cortical development. The dominant pattern of electrical activity in the neonatal rat neocortex in vivo is a spatially confined spindle-burst. Here, we studied network mechanisms of generation of spindle-bursts in the barrel cortex of neonatal rats using a superfused cortex preparation in vivo. Both spontaneous and sensory-evoked spindle-bursts were present in the superfused barrel cortex. Pharmacological analysis revealed that spindle-bursts are driven by glutamatergic synapses with a major contribution of AMPA/kainate receptors, but slight participation of NMDA receptors and gap junctions. Although GABAergic synapses contributed minimally to the pacing the rhythm of spindle-burst oscillations, surround GABAergic inhibition appeared to be crucial for their compartmentalization. We propose that local spindle-burst oscillations, driven by glutamatergic synapses and spatially confined by GABAergic synapses, contribute to the development of barrel cortex during the critical period of developmental plasticity.

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Attenuation of the Early Gamma Oscillations During the Sensory-Evoked Response in the Neonatal Rat Barrel Cortex

BioNanoScience ◽

10.1007/s12668-016-0289-7 ◽

2016 ◽

Vol 6 (4) ◽

pp. 575-577 ◽

Cited By ~ 1

Author(s):

Dmitrii Suchkov ◽

Mikhail Sintsov ◽

Lyailya Sharipzyanova ◽

Roustem Khazipov ◽

Marat Minlebaev

Keyword(s):

Barrel Cortex ◽

Gamma Oscillations ◽

Evoked Response ◽

Neonatal Rat ◽

Sensory Evoked

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Developmental Changes in the Fidelity and Short-Term Plasticity of GABAergic Synapses in the Neonatal Rat Dorsal Horn

Journal of Neurophysiology ◽

10.1152/jn.01342.2007 ◽

2008 ◽

Vol 99 (6) ◽

pp. 3144-3150 ◽

Cited By ~ 18

Author(s):

Rachel A. Ingram ◽

Maria Fitzgerald ◽

Mark L. Baccei

Keyword(s):

Spinal Cord ◽

Dorsal Horn ◽

Receptive Fields ◽

Neuronal Firing ◽

Neonatal Rat ◽

Superficial Dorsal Horn ◽

Short Term ◽

Dorsal Horn Neurons ◽

Gabaergic Synapses

The lower thresholds and increased excitability of dorsal horn neurons in the neonatal rat suggest that inhibitory processing is less efficient in the immature spinal cord. This is unlikely to be explained by an absence of functional GABAergic inhibition because antagonism of γ-aminobutyric acid (GABA) type A receptors augments neuronal firing in vivo from the first days of life. However, it is possible that more subtle deficits in GABAergic signaling exist in the neonate, such as decreased reliability of transmission or greater depression during repetitive stimulation, both of which could influence the relative excitability of the immature spinal cord. To address this issue we examined monosynaptic GABAergic inputs onto superficial dorsal horn neurons using whole cell patch-clamp recordings made in spinal cord slices at a range of postnatal ages (P3, P10, and P21). The amplitudes of evoked inhibitory postsynaptic currents (IPSCs) were significantly lower and showed greater variability in younger animals, suggesting a lower fidelity of GABAergic signaling at early postnatal ages. Paired-pulse ratios were similar throughout the postnatal period, whereas trains of stimuli (1, 5, 10, and 20 Hz) revealed frequency-dependent short-term depression (STD) of IPSCs at all ages. Although the magnitude of STD did not differ between ages, the recovery from depression was significantly slower at immature GABAergic synapses. These properties may affect the integration of synaptic inputs within developing superficial dorsal horn neurons and thus contribute to their larger receptive fields and enhanced afterdischarge.

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Environmental enrichment differentially modifies specific components of sensory-evoked activity in rat barrel cortex as revealed by simultaneous electrophysiological recordings and optical imaging in vivo

Neuroscience ◽

10.1016/j.neuroscience.2010.07.029 ◽

2010 ◽

Vol 170 (2) ◽

pp. 662-669 ◽

Cited By ~ 14

Author(s):

I.M. Devonshire ◽

E.J. Dommett ◽

T.H. Grandy ◽

A.C. Halliday ◽

S.A. Greenfield

Keyword(s):

Optical Imaging ◽

Environmental Enrichment ◽

Barrel Cortex ◽

Electrophysiological Recordings ◽

Evoked Activity ◽

Sensory Evoked

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Laminar and Columnar Structure of Sensory-Evoked Multineuronal Spike Sequences in Adult Rat Barrel Cortex In Vivo

Cerebral Cortex ◽

10.1093/cercor/bhu007 ◽

2014 ◽

Vol 25 (8) ◽

pp. 2001-2021 ◽

Cited By ~ 42

Author(s):

Vicente Reyes-Puerta ◽

Jyh-Jang Sun ◽

Suam Kim ◽

Werner Kilb ◽

Heiko J. Luhmann

Keyword(s):

Barrel Cortex ◽

Columnar Structure ◽

Adult Rat ◽

Spike Sequences ◽

Sensory Evoked

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The Effects of Fluoxetine on Sensory-Evoked Responses in the Neonatal Rat Barrel Cortex

BioNanoScience ◽

10.1007/s12668-016-0370-2 ◽

2016 ◽

Vol 7 (2) ◽

pp. 378-381

Author(s):

Daria Vinokurova ◽

Andrey Zakharov ◽

Dinara Akhmetshina ◽

Azat Nasretdinov ◽

Guzel Valeeva ◽

...

Keyword(s):

Barrel Cortex ◽

Neonatal Rat ◽

Evoked Responses ◽

Sensory Evoked

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Spindle Bursts in Neonatal Rat Cerebral Cortex

Neural Plasticity ◽

10.1155/2016/3467832 ◽

2016 ◽

Vol 2016 ◽

pp. 1-11 ◽

Cited By ~ 26

Author(s):

Jenq-Wei Yang ◽

Vicente Reyes-Puerta ◽

Werner Kilb ◽

Heiko J. Luhmann

Keyword(s):

Cerebral Cortex ◽

Gamma Oscillations ◽

Brain Regions ◽

Neonatal Rat ◽

Human Infants ◽

Pathophysiological Role ◽

Cerebral Cortex In Vitro ◽

Sensory Evoked

Spontaneous and sensory evoked spindle bursts represent a functional hallmark of the developing cerebral cortex in vitro and in vivo. They have been observed in various neocortical areas of numerous species, including newborn rodents and preterm human infants. Spindle bursts are generated in complex neocortical-subcortical circuits involving in many cases the participation of motor brain regions. Together with early gamma oscillations, spindle bursts synchronize the activity of a local neuronal network organized in a cortical column. Disturbances in spindle burst activity during corticogenesis may contribute to disorders in cortical architecture and in the activity-dependent control of programmed cell death. In this review we discuss (i) the functional properties of spindle bursts, (ii) the mechanisms underlying their generation, (iii) the synchronous patterns and cortical networks associated with spindle bursts, and (iv) the physiological and pathophysiological role of spindle bursts during early cortical development.

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Robustness of sensory-evoked excitation is increased by inhibitory inputs to distal apical tuft dendrites

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1518773112 ◽

2015 ◽

Vol 112 (45) ◽

pp. 14072-14077 ◽

Cited By ~ 18

Author(s):

Robert Egger ◽

Arno C. Schmitt ◽

Damian J. Wallace ◽

Bert Sakmann ◽

Marcel Oberlaender ◽

...

Keyword(s):

Synaptic Input ◽

Pyramidal Neurons ◽

Barrel Cortex ◽

Cell Types ◽

Cortical Layer ◽

Evoked Responses ◽

Apical Tuft ◽

Sensory Evoked ◽

Pharmacological Manipulations

Cortical inhibitory interneurons (INs) are subdivided into a variety of morphologically and functionally specialized cell types. How the respective specific properties translate into mechanisms that regulate sensory-evoked responses of pyramidal neurons (PNs) remains unknown. Here, we investigated how INs located in cortical layer 1 (L1) of rat barrel cortex affect whisker-evoked responses of L2 PNs. To do so we combined in vivo electrophysiology and morphological reconstructions with computational modeling. We show that whisker-evoked membrane depolarization in L2 PNs arises from highly specialized spatiotemporal synaptic input patterns. Temporally L1 INs and L2–5 PNs provide near synchronous synaptic input. Spatially synaptic contacts from L1 INs target distal apical tuft dendrites, whereas PNs primarily innervate basal and proximal apical dendrites. Simulations of such constrained synaptic input patterns predicted that inactivation of L1 INs increases trial-to-trial variability of whisker-evoked responses in L2 PNs. The in silico predictions were confirmed in vivo by L1-specific pharmacological manipulations. We present a mechanism—consistent with the theory of distal dendritic shunting—that can regulate the robustness of sensory-evoked responses in PNs without affecting response amplitude or latency.

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Experience-dependent Changes in Basal Dendritic Branching of Layer 2/3 Pyramidal Neurons During a Critical Period for Developmental Plasticity in Rat Barrel Cortex

Cerebral Cortex ◽

10.1093/cercor/bhh026 ◽

2004 ◽

Vol 14 (6) ◽

pp. 655-664 ◽

Cited By ~ 49

Author(s):

M. Maravall

Keyword(s):

Critical Period ◽

Developmental Plasticity ◽

Pyramidal Neurons ◽

Barrel Cortex ◽

Dendritic Branching ◽

Layer 2

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In Vivo Two-Photon Imaging of Neuronal and Vascular Responses in Mice Chronically Exposed to Ethanol

10.1101/471763 ◽

2018 ◽

Author(s):

Phillip O’Herron ◽

Phillip M. Summers ◽

Andy Y. Shih ◽

Prakash Kara ◽

John J. Woodward

Keyword(s):

Chronic Exposure ◽

Barrel Cortex ◽

Laser Scanning Microscopy ◽

Vascular Responses ◽

Cranial Window ◽

Sensory Evoked ◽

Acute And Chronic Exposure ◽

The Impact

AbstractThe effects of ethanol on brain function have been extensively studied using a variety of in vitro and in vivo techniques. For example, electrophysiological studies using brain slices from rodents and nonhuman primates have demonstrated that acute and chronic exposure to ethanol alters the intrinsic excitability and synaptic signaling of neurons within cortical and sub-cortical areas of the brain. In humans, neuroimaging studies reveal alterations in measures of brain activation and connectivity in subjects with alcohol use disorders. While complementary, these methods are inherently limited due to issues related to either disruption of normal sensory input (in vitro slice studies) or resolution (whole brain imaging). In the present study, we used 2-photon laser scanning microscopy in intact animals to assess the impact of chronic ethanol exposure on sensory evoked neuronal and vascular responses. Adult male C57BL/6J mice were exposed to 4 weekly cycles of chronic intermittent ethanol (CIE) exposure while control mice were exposed to air. After withdrawal (≤ 72 hr), a cranial window was placed over the primary visual cortex (V1) and sensory evoked responses were monitored using the calcium indicator OGB-1. CIE exposure produced small but significant changes in response amplitude (decrease) and orientation selectivity of V1 neurons (increase). While arteriole diameter did not differ between control and CIE mice under baseline conditions, sensory-evoked dilation was enhanced in vessels from CIE exposed mice as compared to controls. This was accompanied by a reduced latency in response to stimulation. In separate experiments, pial arteriole diameter was measured in the barrel cortex of control and CIE exposed mice. Baseline diameter of barrel cortex arterioles was similar between control and CIE exposed mice but unlike vessels in V1, sensory-evoked dilation of barrel cortex arterioles was similar between the two groups. Together the results of these studies suggest that chronic exposure to alcohol induces changes in neurovascular coupling that are region dependent.

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