An important requisite for understanding brain function is the identification of behavior and cell activity correlates. Silicon probes are advanced electrodes for large-scale electrophysiological recording of neuronal activity, but the procedures for their chronic implantation are still underdeveloped. The activity of hippocampal place cells is known to correlate with an animal's position in the environment, but the underlying mechanisms are still unclear. To investigate place cells, here we describe a set of techniques which range from the fabrication of devices for chronic silicon probe implants to the monitoring of place field activity in a cue-enriched treadmill apparatus. A micro-drive and a hat are built by fitting and fastening together 3D-printed plastic parts. A silicon probe is mounted on the micro-drive, cleaned, and coated with dye. A first surgery is performed to fix the hat on the skull of a mouse. Small landmarks are fabricated and attached to the belt of a treadmill. The mouse is trained to run head-fixed on the treadmill. A second surgery is performed to implant the silicon probe in the hippocampus, following which broadband electrophysiological signals are recorded. Finally, the silicon probe is recovered and cleaned for reuse. The analysis of place cell activity in the treadmill reveals a diversity of place field mechanisms, outlining the benefit of the approach.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5752405 | PMC |
http://dx.doi.org/10.3791/56438 | DOI Listing |
ACS Biomater Sci Eng
January 2025
Environment Emission and CRM Section, CSIR-Central Institute of Mining and Fuel Research Dhanbad, Jharkhand, 828108, India.
Carbohydrate-functionalized quantum dots exhibit excellent physical characteristics and enhance the steric interaction with biological cells and tissues. Glycoconjugation of quantum dots promotes aqueous solubility, stability, and reduced immunogenicity. Carbohydrate-protein interactions are involved in various vital processes and provide insight into cellular recognition, cell-to-cell communication, pathogenicity, antigen-antibody recognition, and enzymatic action.
View Article and Find Full Text PDFNanoscale
January 2025
Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583.
The widespread proliferation and increasing use of portable electronic devices and wearables, and the recent developments in artificial intelligence and internet-of-things, have fuelled the need for high-density and low-voltage non-volatile memory devices. Nanocrystal memory, an emergent non-volatile memory (NVM) device that makes use of the Coulomb blockade effect, can potentially result in the scaling of the tunnel dielectric layer to a very small thickness. Since the nanocrystals are electrically isolated, potential charge leakage paths localized defects in the thin tunnel dielectric can be substantially reduced, unlike that in a continuous polysilicon floating gate structure.
View Article and Find Full Text PDFDiverse sources of inhibition serve to modulate circuits and control cell assembly spiking across various timescales. For example, in hippocampus area CA1 the competition between inhibition and excitation organizes spike timing of pyramidal cells (PYR) in network events, including sharp wave-ripples (SPW-R). Specific cellular-synaptic sources of inhibition in SPW-R remain unclear, as there are >20 types of GABAergic interneurons in CA1.
View Article and Find Full Text PDFUnlabelled: Layer 6 corticothalamic (L6CT) neurons project to both cortex and thalamus, inducing multiple effects including the modulation of cortical and thalamic firing, and the emergence of high gamma oscillations in the cortical local field potential (LFP). We hypothesize that the high gamma oscillations driven by L6CT neuron activation are shaped by the dynamic engagement of intracortical and cortico-thalamo-cortical circuits. To test this, we optogenetically activated L6CT neurons in NTSR1-cre mice expressing channelrhodopsin-2 in L6CT neurons.
View Article and Find Full Text PDFAlzheimer's disease (AD) is a neurodegenerative disease characterized by progressive impairments in episodic and spatial memory, as well as circuit and network-level dysfunction. While functional impairments in medial entorhinal cortex (MEC) and hippocampus (HPC) have been observed in patients and rodent models of AD, it remains unclear how communication between these regions breaks down in disease, and what specific physiological changes are associated with the onset of memory impairment. We used silicon probes to simultaneously record neural activity in MEC and hippocampus before or after the onset of spatial memory impairment in the 3xTg mouse model of AD pathology.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!