Development of 3-D Multi-Electrode Arrays for Use with Acute Tissue Slices (original) (raw)
Journal of Neuroscience Methods, 1995
Electrical stimulation of nervous tissue with single stimulating electrodes is a technique widely used for the investigation of nervous system function. While it has proved to be useful in all kinds of experiments, single electrode stimuli are: however, far from being 'natural'. In most parts of the living brain, incoming activity results from the firing of a large number of presynaptic neurons, thus reflecting a complex combination of space and time aspects of neural activity. In this paper, a multi-electrode stimulating system is introduced which allows for the generation of fast space-time stimulus patterns. An example for the application of dynamic input patterns to the cerebellar cortex in vitro is given. The corresponding experiments revealed aspects of cerebeliar function which cannot be seen using static or single electrode stimulation.
Microelectrode arrays for stimulation of neural slice preparations
Journal of Neuroscience Methods, 1997
A planar 6×6 array of iridium electrodes with four reference electrodes has been developed for use with neural tissue preparations. Precise knowledge of the relative locations of the array elements allows for spatial neurophysiological analyses. The 10 μm diameter platinized iridium electrodes on a 100 μm pitch have been used to stimulate acutely prepared slices of spinal cord from free-ranging rodents. An intracellular recording from a single neuron in the substantia gelatinosa (SG) using the whole-cell, tight-seal technique allowed low noise, high resolution studies of excitatory or inhibitory electrical responses of a given neuron to inputs from the primary afferent fibers or from stimulation by individual electrodes of the array. The resulting maps of responses provide an indication of the interconnectivity of neural processes. The pattern emerging is that of limited interconnectivity in the SG from areas surrounding a recorded neuron but with strong excitatory or inhibitory effects from those oriented in a longitudinal (rostral–caudal) direction relative to the neuron. The observations to date suggest the neurons of the SG are arranged in sets of independent networks, possibly related to sensory modality and input from particular body regions.
The Journal of Comparative Neurology, 2003
Hippocampal slices often have more synapses than perfusion-fixed hippocampus, but the cause of this synaptogenesis is unclear. Ultrastructural evidence for synaptogenic triggers during slice preparation was investigated in 21-day-old rats. Slices chopped under warm or chilled conditions and fixed after 0, 5, 25, 60, or 180 minutes of incubation in an interface chamber were compared with hippocampi fixed by perfusion or by immersion of the whole hippocampus. There was no significant synaptogenesis in these slices compared with perfusion-fixed hippocampus, but there were other structural changes during slice preparation and recovery in vitro. Whole hippocampus and slices prepared under warm conditions exhibited an increase in axonal coated vesicles, suggesting widespread neurotransmitter release. Glycogen granules were depleted from astrocytes and neurons in 0-min slices, began to reappear by 1 hour, and had fully recovered by 3 hours. Dendritic microtubules were initially disassembled in slices, but reassembled into normal axial arrays after 5 minutes. Microtubules were short at 5 minutes (12.3 Ϯ 1.1 m) but had recovered normal lengths by 3 hours (84.6 Ϯ 20.0 m) compared with perfusion-fixed hippocampus (91 Ϯ 22 m). Microtubules appeared transiently in 15 Ϯ 3% and 9 Ϯ 4% of dendritic spines 5 and 25 minutes after incubation, respectively. Spine microtubules were absent from perfusion-fixed hippocampus and 3-hour slices. Ice-cold dissection and vibratomy in media that blocked activity initially produced less glycogen loss, coated vesicles, and microtubule disassembly. Submersing these slices in normal oxygenated media at 34°C led to glycogen depletion, as well as increased coated vesicles and microtubule disassembly within 1 minute. J. Comp. Neurol. 465:90 -103, 2003.
Preparation of Slice Cultures from Rodent Hippocampus
Cold Spring Harbor protocols, 2017
This protocol describes the preparation of hippocampal slice cultures from rat or mouse pups using sterile conditions that do not require the use of antibiotics or antimycotics. Combining very good optical and electrophysiological accessibility with a lifetime approaching that of the intact animal, many fundamental questions about synaptic plasticity and long-term dynamics of network connectivity can be addressed with this preparation.
Journal of neuroscience methods, 2012
We designed an electrophysiology system to record from 16 separate brain slices simultaneously. The system is able to obtain stable, extracellular responses from the CA1 region of the hippocampus. The system is able to record NMDA-dependent long-term potentiation. The system can record functional loss and recovery during an oxygen and glucose deprivation insult. The system is both cost-and space-efficient, reduces data variability and minimizes animal use.
Pfl�gers Archiv European Journal of Physiology, 1989
(1) A preparation is described which allows patch clamp recordings to be made on mammalian central nervous system (CNS) neurones in situ. (2) A vibrating tissue slicer was used to cut thin slices in which individual neurones could be identified visually. Localized cleaning of cell somata with physiological saline freed the cell membrane, allowing the formation of a high resistance seal between the membrane and the patch pipette. (3) The various configurations of the patch clamp technique were used to demonstrate recording of membrane potential, whole cell currents and single channel currents from neurones and isolated patches. (4) The patch clamp technique was used to record from neurones filled with fluorescent dyes. Staining was achieved by filling cells during recording or by previous retrograde labelling. (5) Thin slice cleaning and patch clamp techniques were shown to be applicable to the spinal cord and almost any brain region and to various species. These techniques are also applicable to animals of a wide variety of postnatal ages, from newborn to adult.
European Journal of Neuroscience, 2008
Arrays of planar electrodes are often applied to record spatial patterns of neuronal field potentials in acute brain slices. The approach is hampered by layers of inactive tissue caused by the cutting process and also by a film of bath electrolyte that may exist between the slice and the substrate. To address this issue, we used a micropipette electrode to measure the vertical profile of evoked field potentials across acute slices from mouse hippocampus. In this way, we found that the signal due to an excitatory postsynaptic potential (EPSP) at the bottom of the slice was about 40% of the maximum at its centre. The vertical profile was matched by a volume-conductor model with proper boundary conditions. Simultaneously, voltage transients caused by EPSPs were measured with a field-effect transistor in the substrate. The transistor signals were in agreement with the evoked field potentials at the bottom of the slice. The study demonstrates: (i) that the loss of signal amplitude from the centre of a slice to the bottom is modest, despite an inactive tissue layer; and (ii) that in principle, planar sensors are able to record the field potential at the bottom of a slice. The results raise questions about the small voltages that are often observed with planar metal electrodes and about the reconstruction of the neuronal activity from field potentials at the bottom of acute slices using current-source density analysis. Methods Acute slices Acute hippocampal slices were prepared by standard techniques. All animal procedures were performed in accordance with national and EU law. In short, male wild-type C57BL ⁄ 6 mice (postnatal day 40-60) were decapitated under diethyl ether anaesthesia. After quick dissection, the brains were placed for 3 min in ice-cold artificial cerebrospinal fluid (ACSF) (Edwards et al., 1989
Organotypic Hippocampal Slice Cultures for Studies of Brain Damage, Neuroprotection and Neurorepair
Current Drug Target -CNS & Neurological Disorders, 2005
Slices of developing brain tissue can be grown for several weeks as socalled organotypic slice cultures. Here we summarize and review studies using hippocampal slice cultures to investigate mechanisms and treatment strategies for the neurodegenerative disorders like stroke (cerebral ischemia), Alzheimer's disease (AD) and epilepsia. Studies of non-excitotoxic neurotoxic compounds and the experimental use of slice cultures in studies of HIV neurotoxicity, traumatic brain injury (TBI) and neurogenesis are included. For cerebral ischemia, experimental models with oxygen-glucose deprivation (OGD) and exposure to glutamate receptor agonists (excitotoxins) are reviewed. For epilepsia, focus is on induction of seizures with effects on neuronal loss, axonal sprouting and neurogenesis. For Alzheimer's disease, the review centers on the use of beta-amyloid (Abeta) in different models, while the section on repair is focused on neurogenesis and cell migration. The culturing techniques, set-up of models, and analytical tools, including markers for neurodegeneration, like the fluorescent dye propidium iodide (PI), are reviewed and discussed. Comparisons are made between hippocampal slice cultures and other in vitro models using dispersed cell cultures, experimental in vivo models, and in some instances, clinical trials. New techniques including slice culturing of hippocampal tissue from transgenic mice as well as more mature brain tissue, and slice cultures coupled to microelectrode arrays (MEAs), on-line biosensor monitoring, and time-lapse fluorescence microscopy are also presented.
Journal of Neuroscience Methods, 1999
The present paper describes a new planar multielectrode array (the MED probe) and its electronics (the MED system) which perform electrophysiological studies on acute hippocampal slices. The MED probe has 64 planar microelectrodes, is covered with a non-toxic, uniform insulation layer, and is further coated with polyethylenimine and serum. The MED probe is shown to be appropriate for both stimulation and recording. In particular, multi-channel recordings of field EPSPs obtained by stimulating with a pair of planar microelectrodes were established for rat hippocampal acute slices. The recordings were stable for 6 h. Finally a spatial distribution of long-term potentiation was studied using the MED system.