Electrophysiology offers a different approach to monitoring neuronal communication, and studying the effects of compounds at the synaptic- level.
Electrophysiology monitors neuron-to-neuron communication by assessing neuronal activity. Small electrical signals of action, membrane or synaptic potentials are amplified and recorded using state of the art equipement. We offer a full range of electrophysiology assays from in-vitro to in-vivo and, when deployed alone or in combination with other techniques, clients enjoy increased value and efficiency in their drug development process. Our collective expertise and experience is most effective when applying our capabilities toward customized programs, designed to meet your specific needs and requirements.
Measuring monoamine levels in prefrontal cortex
Client wanted to understand how H3 antagonist / inverse agonist mediated an increase in monoamine levels in the prefrontal cortex of freely moving rats.
We designed a study combining data from microdialysis and single-unit recordings. Microdialysis confirmed the observation that monoamine levels were increased in the prefrontal cortex. Single unit electrophysiological experiments in different brain areas were performed to see which neuronal pathway was involved.
It is known that H3 receptors function as heteroreceptors. Therefore, H3 receptors control the release of other transmitters than only histamine. The client wanted to understand if this was the only mechanism behind the increase seen with microdialysis.
The histamine H3 inverse agonist – thioperamide – was found to significantly increase the firing rate of of DA neurons in the Ventral Tegmental Area without affecting 5-HT neuron firing in the Dorsal Raphe Nucleus or norepinephrine neuron firing in the Locus Coeruleus. Although the H3 inverse agonist effected DA cell firing, concomitant microdialysis demonstrated that all three neurotransmitters were elevated.
In vivo Single Cell Recording
We perform a variety of in vivo single-cell recording studies, testing either acute effect of a compound on an individual neuron, or the effect of pre-treatment with a drug on the spontaneous firing activity and firing rate of multiple neurons, via multiple-track recordings from different brain areas.
Recorded neurons include:
- Dopamine (Substantia Nigra and Ventral Tegmental Area)
- Histamine (Tuberomammillary nucleus)
- Norepinephrine (Locus Coeruleus)
- Glutamate pyramidal neurons (Prefrontal cortex/Hippocampus)
- Serotonin (Medial Raphe Nucleus and Dorsal Raphe Nucleus)
Long-term Potentiation (LTP)
We measure long-term potentiation both in vivo and in vitro from rat and mouse brains, including deficits induced by MK-801 or scopolamine.
In vitro / Ex vivo Patch Clamp
With in vitro / ex vivo patch clamp recording, our scientists can directly measure neuronal activity of a single cell or channel (receptor) or quantify synaptic inputs from excitatory and inhibitory circuits in tissue obtained from living animals. In combination with other techniques – like microdialysis or behavior study – as part of a customized program, the drug discovery process gains greater speed and efficiency.
Patch clamp electrophysiology configurations:
- Whole cell
- Perforated patch
- Light Sensitive
- Cell culture (overexpression)
- Primary culture
- Acutely dissociated cells
H and M Reflexes
Many neurological conditions affect lower back pain and spasticity in patients, and H-reflexes offer a valuable method for assessing the monosynaptic reflex in the spinal cord.
Iontophoretic compound administration
We can test compound efficacy on neuronal firing by local application of the test compound.
We can determine the most effective compound concentration for specific receptors by using cultured cells’ expression of those receptors.
We welcome your challenge. Please use our response form to indicate any special technique or method that would be of interest, and we will follow up with recommendations.