Electrical stimulation

For the long term aim to develop a visual cortical prosthesis, optogenetic stimulation of primary visual cortex (V1) provides a more specific alternative to electrical stimulation. However, adoption of optogenetic techniques from rodents to macaques as an intermediate step towards humans has proven to be challenging. Here we present prelimnary results, directly comparing effects obtained from optogenetic vs electrical stimulation of macaque V1.We injected AAV9-CamKIIa-ChrimsonR-mScarlet-KV2.1 into macaque V1 under electrophysiological guidance. We first investigated neural activity in response

By applying electrical stimulation, retinal prostheses aim to bypass dysfunctional photoreceptors and directly activate retinal ganglion cells (RGCs). Therefore, effective modulation of RGCs is the key step in the development of retinal prostheses. Six cynomolgus monkeys were used: three as a control and the other three as an N-methyl-N-nitrosourea (MNU)-induced retinal degeneration model. The retinal recording was performed using the 8x8 multi-electrode array. Figure shows the electrical stimulation pulses (a), raster plots of RGC spikes (b), and the modulation efficiency score (MES) (c). The

…Furthermore, direct electrical stimulation of the BLA in humans enhances declarative memory, and this memory enhancement is marked by oscillatory interactions between the BLA and hippocampus. However, the BLA disproportionately projects to the anterior hippocampus compared to the posterior hippocampus, regions that process non-spatial information about objects and spatial information about scenes, respectively. Nevertheless, the premise th

We previously have demonstrated that brief electrical stimulation to the basolateral amygdala (BLA) reliably enhances declarative memory in humans after a one-day delay without eliciting an emotional response. In the current study 31 drug-resistant epilepsy patients undergoing stereo EEG surgery with depth electrode contacts implanted in various MLT regions. During continuous intracranial EEG recording, each participant was presented with a series of images of neutral objects. Across patients, we delivered a brief stimulation to the BLA (8 trains of 50-Hz pulses at 0.5 mA) before, during, or a

Cochlear Implants (CI) have been successful at restoring meaningful hearing perception in many deaf patients. However, rehabilitation for patients with damaged auditory nerves are scarce: the only alternative is the Auditory Brainstem Implant (ABI), which presents poor clinical outcomes and difficult surgical approach.Here, we propose to target the auditory cortex directly, using a soft auditory cortex implant, for hearing restoration. By leveraging microfabrication techniques, we developed soft Electrocorticography (ECoG) arrays that would conform the curvilinear surface of the cortex, suppor

Our study investigates the potential synergistic effect of regenerative therapy combining electrical stimulation with application of anti-inflammatory drug atorvastatin (ATR) following spinal cord injury (SCI). Using an isoflurane anesthesia, we induced SCI at the T9 segment with a compression device for 15 minutes under a 40g weight. An oscillating field stimulator (OFS) implanted subcutaneously delivered a weak electric current (50 µA), alternating polarity every 15 minutes for 6 weeks to encourage axonal growth from the lesion site. Wistar albino female rats were randomly divided to four gr

…ball that gave them (or not) an electrical stimulation at the finger, in a probabilistic manner. Participants had

To investigate the circuit-level neural mechanisms of behavior, simultaneous imaging of neuronal activity in multiple cortical and subcortical regions is highly desired. Miniature head-mounted microscopes offer the capability of calcium imaging in freely behaving animals. However, implanting multiple microscopes on a mouse brain remains challenging due to space constraints and the cumbersome weight of the equipment. Here, we present TINIscope, a Tightly Integrated Neuronal Imaging microscope optimized for electronic and opto-mechanical design. With its compact and lightweight design of 0.43 g,

…Electrical stimulation of the spinal cord, in combination with rehabilitative training, improves hand and arm functions following cervical SCI, but is insufficient to fully restore functions. An eventual cure for SCI will therefore require biological repair strategies to promote axon growth through or around lesions. We recently leveraged our developmentally inspired regenerative gene therapy to restore walking after paralysis due to anatomi

…relies on the emission of electrical (and chemical) stimuli, the employment of electrical stimulation becomes crucial for a comprehensive exploration of neuronal assemblies, to

…Closed-loop brain stimulation precisely aligned to the structure of ongoing activity can be a powerful tool for understanding brain function and providing interventions to ameliorate pathological activity. OscillTrack is a computationally lightweight approach to track primarily the phase and also the amplitude of a waxing and waning oscillation within a frequency band of interest. OscillTrack directly operates o

Research on conscious somatosensory perception has mainly relied on electrical stimulation. Here, we directly compare the event-related potentials evoked by tactile vs. electrical peri-threshold stimulation, using a matching task to control for post-perceptual processes. EEG was recorded while participants received either electrical pulses to the left median nerve (n=24) or tactile stimulation at the left index finger (n=25). To control for confounding processes, participants did not directly report their experience, but indicated via saccades whether they experienced a match or a mismatch bet

Visual prostheses (VP) address vision loss by electrically stimulating neuronal activity within the visual pathway, effectively bypassing the damaged site and providing individuals with phosphene perception. An ideal VP should capture images in real-time and stimulate visual pathways based on the image content, creating precepts that accurately represent the visual scene in front of the user, using phosphenes as building blocks. At present, however, the perception provided by the VP is rudimentary and markedly distinct from natural vision. Here, we evaluated whether pattern stimulation through

…response to both light and electrical stimulation. The model included 11,138 c

Attractors play a key role in a wide range of processes including learning, memory, decision making and navigation. Due to recent innovations in recording methods, there is increasing evidence for the existence of attractor dynamics in the brain. Yet, our understanding of how these attractors emerge or disappear in a biological system is lacking. In vitro cultured cortical neurons have been used extensively as a realistic experimental tool to understand the underlying mechanisms in neuronal assemblies. One of the main characteristics of the activity of such networks are the spontaneous synchro

The development of circuit-based therapeutics to treat neurological and neuropsychiatric diseases require detailed localization and understanding of electrophysiological signals in the human brain. Electrodes can record and stimulate circuits in many ways, and we often rely on non-invasive imaging methods to predict the location to implant electrodes. However, electrophysiological and imaging signals measure the underlying tissue in a fundamentally different manner. To integrate multimodal data and benefit from these complementary measurements, I will describe an approach that considers how di

Electrical stimulation of a neural population may enable direct experiments relating local population activity with subsequent neural or behavioral processes. However, current stimulation approaches do not attempt precise control of population activity, in part due to the difficulty of characterizing diverse neural responses to varied stimulation patterns. We address this gap by building deep network models that extract neuronal spiking responses through stimulation and predict population responses to arbitrary spatiotemporal stimulation trains. To assess the tractability of training accurate

…response to both light and electrical stimulation. The model included 11,138 c

Complex behaviors are constructed out of simple building blocks. The construction of complex behaviors presents an interesting problem when the behavioral building blocks are driven by independent neural dynamics, as is the case for behaviors that recruit central-pattern generators (CPGs). Breathing is a particularly interesting example since it is vital for sustaining life and yet breathing is integrated into a myriad of other behaviors like speaking, laughing, and coughing. Vocalizations co-opt respiratory machinery for communication. While the generation of vocal motor commands is generally

Humans and several animal species, including monkeys, rats, and pigeons, are often strongly motivated to seek information about uncertain future rewards. Remarkably, they prefer information even when it has no objective value for controlling the outcome, suggesting that information has subjective value of its own. In recent years there has been an explosion of research on information seeking in humans and animal models. However, a critical unanswered question is whether the computations that assign subjective value to information are conserved between humans and other species. If so, we could

The vagus nerve is a major pathway by which the brain and the body communicate. Electrical stimulation of the vagus nerve (VNS) is widely used as a therapeutic intervention for epilepsy and there is compelling evidence that it can enhance recovery following stroke. Our work demonstrates that VNS exerts a robust excitatory effect on the brain. First, we establish that VNS triggers an increase in arousal state as measured by behavioral state change. This behavioral state change is linked to an increase in excitatory activity within the cortex. We also show that cholinergic and noradrenergic neur