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

2000 ◽  
Vol 868 (1) ◽  
pp. 39-47 ◽  
Author(s):  
Barry D. Waterhouse ◽  
Robert Mouradian ◽  
Francis M. Sessler ◽  
Rick C.S. Lin
Keyword(s):  
Cortical Neurons ◽  
Barrel Field ◽  
Layer V

Chronic Suppression of Activity in Barrel Field Cortex Downregulates Sensory Responses in Contralateral Barrel Field Cortex

2005 ◽  
Vol 94 (5) ◽  
pp. 3342-3356 ◽  
Author(s):  
Lu Li ◽  
V. Rema ◽  
Ford F. Ebner
Keyword(s):  
Barrel Cortex ◽  
Cortical Excitability ◽  
Single Cells ◽  
Cortical Function ◽  
Adult Rats ◽  
Strong Suppression ◽  
Barrel Field ◽  
Layer V ◽  
Sensory Responses ◽  
Prominent Response

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.

scholarly journals Targeted millisecond-scale activation of cells using non-invasive Sonogenetics

2020 ◽  
Author(s):  
Marc Duque ◽  
Corinne A. Lee-Kubli ◽  
Yusuf Tufail ◽  
Uri Magaram ◽  
Jose Mendoza Lopez ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Transient Receptor Potential ◽  
Neuronal Excitability ◽  
Receptor Potential ◽  
Cell Types ◽  
Mammalian Brain ◽  
Non Invasive ◽  
Transient Receptor Potential A1 ◽  
Layer V ◽  
Transient Receptor

Our understanding of the nervous system has been fundamentally advanced by light- and small molecule-sensitive proteins that can be used to modify neuronal excitability. However, optogenetics requires invasive instrumentation while chemogenetics lacks temporal control. Here, we identify a candidate channel that confers sensitivity to non-invasive ultrasound on millisecond timescales. Using a functional screen, we find that human Transient Receptor Potential A1 (hsTRPA1) increases ultrasound-evoked intracellular calcium levels and membrane potentials. Ultrasound, but not agonist, -evoked, gating of hsTRPA1, requires the N-terminal tip region, intact actin cytoskeleton, and cholesterol, implicating these features in the sonogenetic mechanism. We then use calcium imaging and electrophysiology to confirm that ultrasound-evoked responses of primary neurons are potentiated by hsTRPA1. We also show that unilateral expression of hsTRPA1 in mouse layer V motor cortical neurons leads to ultrasound-evoked contralateral limb responses to ultrasound delivered through an intact skull. Finally, ultrasound induces c-fos in hsTRPA1-expressing neurons, suggesting that our approach can be used for targeted activation of neural circuits. Together, our results demonstrate that hsTRPA1-based sonogenetics can effectively and non-invasively modulate neurons within the intact mammalian brain, a method that could be extended to other cell types across species.

Response properties of vibrissa units in rat SI somatosensory neocortex

1978 ◽  
Vol 41 (3) ◽  
pp. 798-820 ◽  
Author(s):  
D. J. Simons
Keyword(s):  
High Frequency ◽  
Cortical Neurons ◽  
Time Course ◽  
Restricted Range ◽  
Fast Green ◽  
Stimulus Response ◽  
Sinusoidal Oscillations ◽  
Deep Layers ◽  
Layer V ◽  
Sustained Responses

1. Glass microelectrodes were used to record extracellular responses from 308 SI cortical neurons to deflections of the contralateral vibrissae in 21 unanesthetized, paralyzed rats. Controlled deflections of individual hairs were produced by means of an electromechanical stimulator. Fast green dye marks were made to aid histological reconstructions of electrode tracks. 2. TS) were observed throughout layers II--VI; "fast" cortical spikes (FS) were less frequently encountered and largely restricted to layer IV. Although both types of potentials had similar negative-positive waveforms. FSs were distinguished from RSs by their comparatively rapid time course, about half that of RSs. RS units (RSU) discharged spontaneously at rates of less than 1--15/s, whereas FS units (FSU) displayed rates of 15--50/s. The amplitudes of FSs, which were generally smaller than those of RSs, often decreased during high-frequency discharges. 3. With sinusoidal oscillations of a vibrissa FSUs responded more reliably and over a broader range of frequencies (3 to at least 40 Hz) than did RSUs , particularly in layer IV. In addition, FSUs typically responded to whisker deflections over a range of 360 degrees, whereas many RSUs in layer IV displayed sharp spatial-tuning charcteristics, responding over a restricted range of less than 90 degrees. 4. Of all units, 58% responded preferentially to stimulus transients (vibrissal movements), 32% displayed sustained responses to stimulus stead-states (fixed vibrissal displacement). For the remaining 10% of units the appropriate stimulus could not be specified; these units were particularly common in layer V. 5. Computation of quantitative stimulus-response relations showed that many units increased their rate of discharge with increasing stimulus intensities. 6. Most units were directionally selective, responding preferentially to deflections of a whisker in one or more of four quadrants. 7. In radial penetrations through the cortex there was a columnar patern so that units were activated at least by the same (i.e., the "principal") whisker. In a number of cases these could be directly correlated with the barrels. Of all units, 55% responded to deflections of single vibrissa only, the remaining 45% to 2--12 adjacently situated vibrissae. For most multiple-whiser units the responses elicited by deflection of any one hair activating the neuron was qualitatively similar to those elicited by deflection of any other hair activating it. The principal whisker of the penetration was typically associated with the most vigorous responses. 8. In layer IV, 85% of neurons responded to deflections of one hair only, the remaining 15% to two or more hairs. In layers II and III 39% of units were activated by more than one vibrissa; in layers V and VI multiple-whisker units predominated (64%). Whisker configurations in the deep layers were larger than those in other layers. 9...

Layer V Neurons in Mouse Cortex Projecting to Different Targets Have Distinct Physiological Properties

2007 ◽  
Vol 98 (6) ◽  
pp. 3330-3340 ◽  
Author(s):  
Alexis M. Hattox ◽  
Sacha B. Nelson
Keyword(s):  
Cortical Neurons ◽  
Pyramidal Neurons ◽  
Projection Neuron ◽  
Target Form ◽  
Trigeminal Neurons ◽  
Physiological Properties ◽  
Mouse Cortex ◽  
Layer V ◽  
Firing Properties ◽  
Whole Cell Recordings

Layer V pyramidal neurons are anatomically and physiologically heterogeneous and project to multiple intracortical and subcortical targets. However, because most physiological studies of layer V pyramidal neurons have been carried out on unidentified cells, we know little about how anatomical and physiological properties relate to subcortical projection site. Here we combine neuroanatomical tract tracing with whole cell recordings in mouse somatosensory cortex to test whether neurons with the same projection target form discrete subpopulations and whether they have stereotyped physiological properties. Our findings indicate that corticothalamic and -trigeminal neurons are two largely nonoverlapping subpopulations, whereas callosal and corticostriatal neurons overlap extensively. The morphology as well as the intrinsic membrane and firing properties of corticothalamic and corticotrigeminal neurons differ from those of callosal and corticostriatal neurons. In addition, we find that each class of projection neuron exhibits a unique compliment of hyperpolarizing and depolarizing afterpotentials that further suggests that cortical neurons with different subcortical targets are distinct from one another.

NR2B-Containing NMDA Autoreceptors at Synapses on Entorhinal Cortical Neurons

2001 ◽  
Vol 86 (4) ◽  
pp. 1644-1651 ◽  
Author(s):  
Gavin Woodhall ◽  
D. Ieuan Evans ◽  
Mark O. Cunningham ◽  
Roland S. G. Jones
Keyword(s):  
Cortical Neurons ◽  
Glutamate Release ◽  
Nr2b Subunit ◽  
Voltage Gated ◽  
B Subunit ◽  
Selective Agonist ◽  
Bath Application ◽  
Mepsc Frequency ◽  
Layer V

We have previously shown that presynaptic N-methyl-d-aspartate receptors (NMDARs) can facilitate glutamate release onto principal neurons in the entorhinal cortex (EC). In the present study, we have investigated the subunit composition of these presynaptic NMDARs. We recorded miniature α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor–mediated excitatory postsynaptic currents (mEPSCs), from visually identified neurons in layers II and V of the EC in vitro. In both layers, bath application of the NR2A/B subunit–selective agonist, homoquinolinic acid (HQA), resulted in a marked facilitation of mEPSC frequency. Blockade of presynaptic Ca2+ entry through either NMDARs or voltage-gated Ca2+channels with Co2+ prevented the effects of HQA, confirming that Ca2+ entry to the terminal was required for facilitation. When the NR2B-selective antagonist, ifenprodil, was applied prior to HQA, the increase in mEPSC frequency was greatly reduced. In addition, we found that an NMDAR antagonist blocked frequency-dependent facilitation of evoked release and reduced mEPSC frequency in layer V. Thus we have demonstrated that NMDA autoreceptors in layer V of the EC bear the NR2B subunit, and that NMDARs are also present at terminals onto superficial neurons.

scholarly journals Thalamic circuitry and thalamocortical synchrony

2002 ◽  
Vol 357 (1428) ◽  
pp. 1659-1673 ◽  
Author(s):  
Edward G. Jones
Keyword(s):  
Cortical Neurons ◽  
Low Frequency ◽  
Oscillatory Activity ◽  
Reticular Nucleus ◽  
Cortical Cells ◽  
Dorsal Thalamus ◽  
High Frequency Oscillations ◽  
Voltage Dependent ◽  
Layer V ◽  
Layer Vi

The corticothalamic system has an important role in synchronizing the activities of thalamic and cortical neurons. Numerically, its synapses dominate the inputs to relay cells and to the γ–amino butyric acid (GABA)ergic cells of the reticular nucleus (RTN). The capacity of relay neurons to operate in different voltage–dependent functional modes determines that the inputs from the cortex have the capacity directly to excite the relay cells, or indirectly to inhibit them via the RTN, serving to synchronize high– or low–frequency oscillatory activity respectively in the thalamocorticothalamic network. Differences in the α–amino–3–hydroxy–5–methyl–4–isoxazolepropionic acid (AMPA) subunit composition of receptors at synapses formed by branches of the same corticothalamic axon in the RTN and dorsal thalamus are an important element in the capacity of the cortex to synchronize low–frequency oscillations in the network. Interactions of focused corticothalamic axons arising from layer VI cortical cells and diffuse corticothalamic axons arising from layer V cortical cells, with the specifically projecting core relay cells and diffusely projecting matrix cells of the dorsal thalamus, form a substrate for synchronization of widespread populations of cortical and thalamic cells during high–frequency oscillations that underlie discrete conscious events.

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