We describe for the first time the design, implementation, and testing of a telemetry controlled simultaneous stimulation and recording device (SRD) to deliver chronic intercortical microstimulation (ICMS) to physiologically identified sites in rat somatosensory cortex (SI) and test hypotheses that chronic ICMS strengthens interhemispheric pathways and leads to functional reorganization in the enhanced cortex. The SRD is a custom embedded device that uses the Cypress Semiconductor's programmable system on a chip (PSoC) that is remotely controlled via Bluetooth. The SRC can record single or multiunit responses from any two of 12 available inputs at 1-15 ksps per channel and simultaneously deliver stimulus pulses (0-255 μA; 10 V compliance) to two user selectable electrodes using monophasic, biphasic, or pseudophasic stimulation waveforms (duration: 0-5 ms, inter-phase interval: 0-5 ms, frequency: 0.1-5 s, delay: 0-10 ms). The SRD was bench tested and validated in vivo in a rat animal model.
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http://dx.doi.org/10.1109/EMBC.2014.6943619 | DOI Listing |
Nat Commun
December 2024
Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, US.
The correlational structure of brain activity dynamics in the absence of stimuli or behavior is often taken to reveal intrinsic properties of neural function. To test the limits of this assumption, we analyzed peripheral contributions to resting state activity measured by fMRI in unanesthetized, chemically immobilized male rats that emulate human neuroimaging conditions. We find that perturbation of somatosensory input channels modifies correlation strengths that relate somatosensory areas both to one another and to higher-order brain regions, despite the absence of ostensible stimuli or movements.
View Article and Find Full Text PDFElife
December 2024
Department of Neuroscience, Columbia University, New York, United States.
Learning alters cortical representations and improves perception. Apical tuft dendrites in cortical layer 1, which are unique in their connectivity and biophysical properties, may be a key site of learning-induced plasticity. We used both two-photon and SCAPE microscopy to longitudinally track tuft-wide calcium spikes in apical dendrites of layer 5 pyramidal neurons in barrel cortex as mice learned a tactile behavior.
View Article and Find Full Text PDFeNeuro
December 2024
Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.
It is widely believed that axons in the central nervous system of adult mammals do not regrow following injury. This failure is thought, at least in part, to underlie the limited recovery of function following injury to the brain or spinal cord. Some studies of fixed tissue have suggested that, counter to dogma, norepinephrine (NE) axons regrow following brain injury.
View Article and Find Full Text PDFNeurobiol Dis
December 2024
Institute of Physiology I, Münster University, Münster, Germany. Electronic address:
Spike-wave-discharges (SWD) are the electrophysiological hallmark of absence epilepsy. SWD are generated in the thalamo-cortical network and a seizure onset zone was identified in the somatosensory cortex (S1). We have shown before that inhibition of the centromedian thalamic nucleus (CM) in GAERS rats resulted in a selective suppression of the spike component while rhythmic cortical 5-9 Hz oscillations remained present.
View Article and Find Full Text PDFHum Brain Mapp
December 2024
Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Intracortical microstimulation (ICMS) is a method for restoring sensation to people with paralysis as part of a bidirectional brain-computer interface (BCI) to restore upper limb function. Evoking tactile sensations of the hand through ICMS requires precise targeting of implanted electrodes. Here we describe the presurgical imaging procedures used to generate functional maps of the hand area of the somatosensory cortex and subsequent planning that guided the implantation of intracortical microelectrode arrays.
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