Circuit control by all-optical synapses
A fascinating collaboration between Ute Hochgeschwender at Central Michigan University and Christopher Moore at Brown University is out in Nature Communications Biology. They combine simultaneous gamma band LFP recordings with NeuroNexus A1x32-Poly2-5mm-50s-177 probes and imaging for bioluminescence directly adjacent to the silicon shank in barrel cortex of luciferase-expressing mice. These recordings confirm Interluminescence: presynaptic bioluminescence activating postsynaptic opsins.
Hippocampal changes in autism phenotypes
NeuroNexus chronic, 32-channel silicon probes were implanted chronically in behaving adult mice expressing autism-spectrum phenotypes. Paterno et al. from Scott Baraban’s lab at UCSF utilized A4x8-5mm-200-400-703-CM32 probes to record hippocampal LFPs and specifically gamma oscillations. They also used hippocampal sharp-wave ripples (SWR) and dentate spikes to localize the probe. Final probe location was determined with DiI, which was applied before implant. See more of their surgical methods and translational results in Cell Reports.
Early misconnectivity in a psychiatric risk model
This Journal of Neuroscience paper by Song and Xu et al. from Dr. Ileana Hanganu-Opatz’s lab presents electrophysiology and optogenetics results using NeuroNexus multi-shank, multi-fiber optoelectrodes (A4x4-5mm-100-125-703-OA16LP). The lateral coverage from multiple shanks positioned recording sites in both layers 2/3 and 5/6 of developing mouse (ages P8-10 and P20-24) prefrontal cortex (PFC). They tested excitation and connectivity between PFC and hippocampus (CA1) in a model of mental disorder.
McMahon et al. and the Michel Lemay lab performed simultaneous spinal cord recordings with two NeuroNexus A8x8-5mm-200-200-177, 64-channel probes. They made multiple insertions with the same probe at different spinal segments, and recordings were made during stepping motion, electrical stimulation, as well as control at rest. Probe location marking with DiO was done after recordings were completed. Read more about their discoveries here.
NeuroNexus optoelectrodes, acute (A1x32-Poly3-10mm-50-177-OA32LP) as well as oDrive-implanted (A1x32-Poly3-10mm-50-177-OH32LP-21mm), are cited in the Cell Press STAR Protocols publication by Tang et al. with Alexandre Charlet’s group. The probes were used for simultaneous electrophysiological recording and opto-tagging of oxytocin neurons. This protocol includes tips for using NeuroNexus oDrives and for spike sorting silicon probe high-density recordings.
Sales et al. at the University of Bristol inserted NeuroNexus A1x32-Poly3-10mm-25s-177 silicon probes into intact, mechanically stabilized nerve fibers 1-5 times per experiment for 5 experiments with consistent impedance and recording quality. They were able to detect action potential conduction along the multi-channel probe within the nerve.
Kimura and Yoshimura (Science Advances) recorded in layer 5 of visual cortex and analyzed single-unit and LFP data from NeuroNexus 2-shank tetrodes (A2x2-tet-3mm-150-150-121) used across multiple penetrations over several days of experiments. They discovered that single neuron and population responses to low-contrast visual stimuli enabled improved perception after training.
Xu et al. from Dr. Ileana Hanganu-Opatz lab used NeuroNexus acute one-shank optoelectrodes (A1x16-5mm-100-703-OA16LP; A1x16-5mm-50-703-OA16LP) and four-shank optoelectrodes (A4x4-3mm-100-125-703-OA16LP) to target and span recording sites across lateral entorhinal cortex (LEC), CA1 area of the hippocampus (HP), and the prelimbic subdivision of prefrontal cortex (PFC), respectively. Their results uncover novel mechanisms of miswiring in the neonatal brain and highlight the critical role of the LEC for the function of prefrontal-hippocampal circuits.
Dr. Troy Margrie’s group from University College London published their new findings in Neuron. They recorded single units in freely moving mice with chronically implanted NeuroNexus probes (A1x32-Poly2-5mm-50s-177-CM32). They found that angular head velocity (AHV) cells in the retrosplenial cortex (RSP) may be used in path integration by updating the spatial map upon animal movement, and may increase the accuracy of self-motion perception.
Dooley et al. from Mark Blumberg’s lab at the University of Iowa examined movement-related activity in ventral lateral (VL) and ventral posterior (VP) thalamic nuclei, as well as primary motor cortex (M1) in postnatal rats, ages P12, P16 and P20. They implanted NeuroNexus probes A1x16-3mm-100-177, A1x16-10mm-100-177, or A2x16-10mm-50-500-177 and recorded single units and twitches. They demonstrate that a cerebellar internal model of movement arises at P20.
The collaborative team of Ivan Soltesz from Stanford University, Attila Losonczy from Columbia University, Gyorgy Buzsaki from New York University and Z. Josh Huang from Cold Spring Harbor and Duke University recently published their results in Neuron. They implanted NeuroNexus Q-trodes (Q1x4-3mm-100-177-HQ4_21mm) for continuous monitoring of sharp wave-ripples in CA1 and 32-channel optoelectrode (A1x32-Poly3-10mm-50-177-OCM32LP) to measure blue light-evoked responses in CA1 of awake mice. Their results show that axo-axonic cells (AACs) are brain-state dependent and correlated with the onset of locomotion or whisking episodes. The postsynaptic effect of AACs on pyramidal cell spike generation is inhibitory and can remap place fields in the CA1 network.
Liu at.al published their results in Nature Communications using NeuroNexus A4x8-5mm microelectrode arrays. Single neuron recordings were captured during optogenetic stimulation with blue, green and red light emitted by trichromatic upcoversion nanoparticles with excitation-specific luminescence. They showed the separation of blue, green, and red color emissions by measuring the spike activity of multiple neuronal populations under selective activation with different wavelengths of near infrared light.
Grosmark et al. from Columbia University published their findings in Nature Neuroscience. They implanted NeuroNexus Qtrodes into the CA1 hippocampus to collect pyramidal cell LFPs contralateral to calcium imaging in mice. They tracked hippocampal place cells over 2 weeks during both online spatial reward learning behavior and offline resting. Their results demonstrate long-lasting, context-specific reactivation of run-related hippocampal neural ensembles as well as the reinstatement of place-related neural sequences. Their findings suggest that post-learning offline memory consolidation plays a complementary and computationally distinct role in learning compared to online encoding.
Sultana et al. used NeuroNexus acute probes to assess whether enzymatic digestion of Perineuronal nets (PNNs) in the prefrontal cortex (PFC) affected neural activity of DISC1 (Disruption in Schizophrenia) mutation mouse model. They found that following chondroitinase treatment, electrophysiological recordings from the PFC exhibited a reduced proportion of spontaneous, high‐frequency firing neurons, and an increased proportion of irregularly firing neurons, with increased spike count and reduced interspike intervals in control animals.
Hirokazo Takahashi’s lab used a NeuroNexus probe to simultaneously target the auditory cortex and thalamus of rats. Their published results in Nature Scientific Reports demonstrate that information flow was dynamic depending on the stimulus processing mode and that thalamo-cortical communication was strengthened during stimulus presentation, while disappeared during spontaneous activity.
Craft et al. recorded from the olfactory bulb (OB) of rats using NeuroNexus 32-channel probes (A4x2-tet design) to capture odor evoked spiking activity of putative mitral cells (MCs). They found significant differences in evoked firing rates and spike count covariances. Then, using data-driven models, they provided a framework for how the brain codes odors with different modes of olfaction.
George Dragoi’s lab at Yale University used chronically implanted Buzsaki64 probes to study populations of simultaneously recorded place cells in rats. Subject exploration of novel environments promoted response generalization, while accumulated experience over several weeks improved discriminability. The results suggest new schemes for how the brain encodes new experiences.
Cristin Welle’s lab recently published their new system for integrating chronic, extracellular electrophysiology using NeuroNexus A1x16-3mm-100-177-CM16LP probes with video data to conduct closed-loop stimulation experiments. The linear array was implanted in the mouse motor cortex and captured spike data from all layers during freely moving reach behaviors. These recordings provided neural data to complement behavioral data such that reach-related activity could be extracted.
Gao et al. with Alexey Ponomarenko’s group in Berlin, Germany published in Nature Communications! NeuroNexus 32-channel linear probes and 8-shank probes were used to record single spikes and complex spike bursts in hippocampal CA1 neurons of awake behaving mice. Experimental manipulations included KCNQ3 genetic mutation affecting pyramidal cell M-type potassium channels and optogenetic disruption of up-stream circuitry. The paper parses out the factors contributing to coordination of spikes and bursts and how these may impact memory function.
Bilal Haider’s lab at Georgia Tech used NeuroNexus 32-channel probes with linear and poly3 layouts to record neural activity across layers of V1 and LGN, respectively, in head-fixed stationary mice. Their results showed that OFF responses dominated in the central visual field, whereas ON and OFF responses were more balanced in the periphery. These findings were consistent across LFP, spikes, and subthreshold membrane potential in V1, and were aligned with spatial biases in ON and OFF responses in LGN.
Edelman et al. from Stanford University implanted NeuroNexus 16-channel linear neural electrodes (A1x16-5mm-50-703-A16) into the bilateral primary motor cortex and striatum of mice. They found that functional ultrasound imaging (fUSI) is a more sensitive hemodynamic readout of optogenetically-induced neuronal activity compared to fMRI. Additionally, they found that LFP signals in the bilateral M1 and striatum co-localized better with fUSI activation patterns than those of fMRI. By isolating the arterial and venous components of the vascular response, they showed that fUSI can map large-scale neural circuit activity with vessel-type specificity.
Winkel et al. used NeuroNexus Optoelectrode (A1x16-10 mm-100-177-OA16LP) and SmartBox neural interface processor to capture local field potential data from V1 of mice. They showed that TrkB activation in PV interneurons dynamically regulates the intrinsic properties of the same interneurons by decreasing their intrinsic excitability and switching the PV network into a plastic configuration, which orchestrates adult cortical plasticity states and mediates the effects of antidepressants on neuronal plasticity.
Carl Schoonover et al. published their results in Nature by implanting NeuroNexus A1x32-Poly3-5mm-25s-177 silicon probes into the primary olfactory cortex of mice. They showed that odor-evoked activity in the mouse anterior piriform cortex exhibits rapid and cumulative reorganization over time.
Multi-shank NeuroNexus 32- and 64-channel probes were used to record across and through rodent visual cortex, while single-shank NeuroNexus probes spanned lateral regions to enable tracking of receptive fields. Penetrations were marked with DiI. The results by Eugenio Piasini and Liviu Soltuzu et al. in Davide Zoccolan’s group revealed a hierarchy in processing of dynamic visual stimuli that includes increasingly sustained responses by deeper “ventral stream” visual areas.
Timothy Brown’s team from the University of Manchester used the NeuroNexus SmartBox and 32-, 64-, and 256-channel probes of three different designs (linear, tetrode, polytrode) to record from lateral geniculate nucleus (LGN) in mice with altered M-cone spectral sensitivity (Opn1mwR). Multispectral stimuli were used to address the color processing and neuron properties at higher visual processing stages. Their findings show that cones alone support a diverse capacity for color discrimination that operates for small spatially localized stimuli and diffuse changes in illumination across a range of light levels, providing a robust substrate for mouse color vision. They also demonstrated that cone inputs to opponent neurons derive from the central and upper visual field.
Multiple NeuroNexus probe designs (A2x32-5mm-25-200-177, A4x8-5mm-100-200-177, Buzsaki32 and Buzsaki64) were used by Andrew King’s lab at Oxford to record from primary sensory cortices, auditory thalamus and inferior colliculus in mice. NeuroNexus probes were also combined with optical stimulation for optogenetics experiments and with DiI dye for acute penetration histology in this study in Nature Communications. The results demonstrate that activity in somatosensory cortex caused by whisker stimulation suppresses sound-evoked activity in primary auditory cortex via the colliculus and thalamus, providing an example of subcortical pathways mediating intra-cortical communication.
Oran et. al used NeuroNexus linear probes (A1x16-10mm-100- 500-177) to evaluate the mechanisms of interhemispheric correlations and their dependence on behavioral state in the barrel cortex of awake mice. They showed that the interhemispheric correlations between the two barrel cortices depend on whisking state, and that the majority of these correlations were decreased during whisking compared to quiet wakefulness. Furthermore, despite general elevated firing rate in the whisking state, the activity of imaged callosal fibers was decreased. These results suggest the causal role of corpus callosum activity in mediating interhemispheric communication, as well as its dependence on the behavioral state of the animal.
Gaillet et al. used the NeuroNexus ECoG array, E32-1000-30-200, to record cortical activity along with a support vector machine classification algorithm to classify cortical responses originating from visual and electrical stimuli. They confirmed an increase in classification accuracy with increased center-to-center separation on patterned visual stimulation. Additionally, their results demonstrated the classification accuracy's dependence on the current amplitude, with higher accuracy at higher amplitudes. They also used a regression model to add a predictive capacity. Using a regression model, they showed that cortical activities elicited by electrical stimulation are meaningfully different, as it highlights features that vary in a linear manner, which can be expected from cortical activity patterns resulting from the stimulation of a gradually shifted portion of the visual field. These results represent a necessary, although not sufficient, condition for an optic nerve prosthesis to deliver vision with non-overlapping phosphene.
Results of Krichberger et al. paper using Neuronexus A1x32-5mm-25-177 linear probes along with optogenetics revealed how figure-ground modulation is necessary for perception. Also, they showed that the interactions between lower (V1) and higher areas of the visual cortex shape visual perception, enabling the co-selection of image elements that belong to a single figure and their segregation from the background.
Richter et al. explored the possibility of exchanging neural information between the brains of guinea pig and human. They determined characteristic frequency and recorded guinea pig inferior colliculus (ICC) neural response patterns to single spoken words with NeuroNexus A1x16-5mm-100-177 probes. The single-word spike trains were then played through corresponding electrodes of cochlear implants in human subjects. Subject performance on a few word recognition tests was better than chance, confirming the possibility of lexical information transmission from an animal auditory system to the human auditory system.
The Kraskov group used NeuroNexus 32-channel polytrodes (A1x32-Poly3-5mm-25s-177) to record fast and slow motor cortex (M1) pyramidal tract neurons (PTNs) in macaque. Their findings emphasize the importance of pairing electrophysiological and optogenetic approaches in classifying neurons into anatomical and morphological categories.
Viejo and Peyrache took advantage of NeuroNexus 8-shank polytrodes to sample from multiple sub-nuclei in the anterior thalamus in awake behaving mice. They were able to identify head direction (HD) cells in the AD nucleus and characterize firing rates and burstiness of HD and non-HD cells. Results demonstrated that AD HD cells specifically increase gain and coherence during hippocampal sharp wave ripples.
Congratulations to the Colonnese lab for their new publication in #eNeuro. They used Poly2 probes for dense acute recordings in mouse pup V1 to demonstrate that retinal input does not govern developmental increases in cortical activity. Their recordings were done with the NeuroNexus SmartBox system. Learn more about the updated system here.
Using NeuroNexus linear arrays, dense sampling through the auditory cortex enabled computation of bipolar derivation LFPs for supragranular and infragranular layers. LFPs were also sampled across the posterior auditory field within the ectosylvian sulcus. This study is a great example of using NeuroNexus probes to target hard-to-reach areas.
There's a new paper out from Dr Tracy Cui's lab in which NeuroNexus probes were tested under precise stimulation conditions. We are proud to provide devices with consistent electrode site properties to enable studies like this. Congratulations Sally Zheng and co-authors!
It's always exciting when translational studies come out with NeuroNexus as part of the basic science.
Congratulations to the authors!
Morgan Urdaneta's publication out of Kevin Otto's lab is here! Read it to see how NeuroNexus linear arrays enabled them to define tachaxies across cortical layers.
Hot off the presses! We're excited about this new publication featuring a one-of-a-kind custom NeuroNexus silicon microelectrode. This probe has two different shank lengths, as well as a combination of recording and simulation electrode sites.
This collaboration between the Dietmar Schmitz and Gyorgy Buzsaki labs utilized 32-channel and 256-channel multi-shank NeuroNexus probes and optoelectrodes. The geometry of the probes enabled positioning shanks in the mouse hippocampus/dentate gyrus, subiculum and granular retrosplenial cortex simultaneously. Through acute electrophysiology and optogenetic manipulation, this team defined a pathway by which sharp wave ripples communicate from the hippocampus to cortex.
This publication in eNeuro provides highlights valuable data obtained from acute recordings with standard NeuroNexus catalog probes in macaque visual cortices. The researchers covered the skull with acrylic resin, performed a craniotomy through the resin, then inserted silicon probes through a slit in the dura. Re-use of the probes and multiple recordings in the same animals were achieved with this method. Original recordings were published here. The present study’s computational results suggest that saliency of visual stimuli are represented in primary visual cortex.
Neuronexus A2x16-10mm-150-500-177-A32, 2-shank laminar probes were used to record the control frequency tuning profile of the guinea pig inferior colliculus. The animals were then acutely deafened and probe recordings were used to characterize inferior colliculus activity during use of cochlear implants with different stimulation profiles. This study in Hearing Research points to a solution for reducing channel interactions in cochlear implants, with the potential to improve speech detection for cochlear implant users.
Koch et al. from John Wolf’s Lab published their study on functional status of hippocampal neurons after traumatic brain injury (TBI). A NeuroNexus 32-channel probe (A1X32-Poly2-5mm-50s-177-H32) was used for laminar recording in CA1 in a rat TBI model. They reported that hippocampal CA1 single-unit activity post-TBI can maintain a normal firing rate despite significantly reduced, layer-specific loss of input. However, maintaining normal synchronization to the dominant oscillations within the hippocampus is impaired.
Lipinski et al. published their study on adult neuron identity recently! A NeuroNexus 32-channel linear array with 50um site spacing (approx 1.5mm recording span) was used to record simultaneously from the CA1 and dentate gyrus in mutant mice with an inducible genetic mutation to delete two transcriptional co-activators. Across acute multi-channel recordings, drops in activity were observed within 2 weeks of genetic ablation.
