Automated in vivo patch-clamp evaluation of extracellular multielectrode array spike recording capability.

Much innovation is currently aimed at improving the number, density, and geometry of electrodes on extracellular multielectrode arrays for in vivo recording of neural activity in the mammalian brain. To choose a multielectrode array configuration for a given neuroscience purpose, or to reveal design principles of future multielectrode arrays, it would be useful to have a systematic way of evaluating the spike recording capability of such arrays. We describe an automated system that performs robotic patch-clamp recording of a neuron being simultaneously recorded via an extracellular multielectrode array. By recording a patch-clamp data set from a neuron while acquiring extracellular recordings from the same neuron, we can evaluate how well the extracellular multielectrode array captures the spiking information from that neuron. To demonstrate the utility of our system, we show that it can provide data from the mammalian cortex to evaluate how the spike sorting performance of a close-packed extracellular multielectrode array is affected by bursting, which alters the shape and amplitude of spikes in a train. We also introduce an algorithmic framework to help evaluate how the number of electrodes in a multielectrode array affects spike sorting, examining how adding more electrodes yields data that can be spike sorted more easily. Our automated methodology may thus help with the evaluation of new electrode designs and configurations, providing empirical guidance on the kinds of electrodes that will be optimal for different brain regions, cell types, and species, for improving the accuracy of spike sorting. NEW & NOTEWORTHY We present an automated strategy for evaluating the spike recording performance of an extracellular multielectrode array, by enabling simultaneous recording of a neuron with both such an array and with patch clamp. We use our robot and accompanying algorithms to evaluate the performance of multielectrode arrays on supporting spike sorting.

Principles of designing interpretable optogenetic behavior experiments.

Over the last decade, there has been much excitement about the use of optogenetic tools to test whether specific cells, regions, and projection pathways are necessary or sufficient for initiating, sustaining, or altering behavior. However, the use of such tools can result in side effects that can complicate experimental design or interpretation. The presence of optogenetic proteins in cells, the effects of heat and light, and the activity of specific ions conducted by optogenetic proteins can result in cellular side effects. At the network level, activation or silencing of defined neural populations can alter the physiology of local or distant circuits, sometimes in undesired ways. We discuss how, in order to design interpretable behavioral experiments using optogenetics, one can understand, and control for, these potential confounds.

On the cost and prevention of iatrogenic multiple pregnancies.

Multiple pregnancies are an undesirable complication of IVF and of ovulation induction and/or ovulation enhancement without IVF. Studies based on published population data and data from the Centers for Disease Control and Prevention indicate that savings from the mitigation of iatrogenic multiples would save money in the billions (10(9)) of US dollars on a national basis. The aim of this study was to determine whether, using real data from a major regional insurance carrier for the interval 2005-2009 covering obstetric costs requiring hospitalization and neonatal costs through the first year, it was possible to show that the cost saved by eliminating iatrogenic multiple births would be adequate to fund a protocol to minimize iatrogenic multiple births. The net savings on an annual basis for the study group of 13,478 was about US$4.4 million. Applying the regional findings to national data suggests savings of approximately US$6.3 billion if national iatrogenic multiples were eliminated. These findings indicate that the health insurance industry should be able to offer infertility coverage at a lower rate by requiring a treatment algorithm designed to essentially eliminate iatrogenic multiple pregnancies. It is concluded that efforts should be made to assure a singleton birth when treating infertility.

Hyperadrenocorticism of calorie restriction contributes to its anti-inflammatory action in mice.

Calorie restriction (CR), which lengthens lifespan in many species, is associated with moderate hyperadrenocorticism and attenuated inflammation. Given the anti-inflammatory action of glucocorticoids, we tested the hypothesis that the hyperadrenocorticism of CR contributes to its attenuated inflammatory response. We used a corticotropin-releasing-hormone knockout (CRHKO) mouse, which is glucocorticoid insufficient. There were four controls groups: CRHKO mice and wild-type (WT) littermates fed either ad libitum (AL) or CR (60% of AL food intake), and three experimental groups: (a) AL-fed CRHKO mice given corticosterone (CORT) in their drinking water titrated to match the integrated 24-hr plasma CORT levels of AL-fed WT mice, (b) CR-fed CRHKO mice given CORT to match the 24-hr CORT levels of AL-fed WT mice, and (c) CR-fed CHRKO mice given CORT to match the 24-hr CORT levels of CR-fed WT mice. Inflammation was measured volumetrically as footpad edema induced by carrageenan injection. As previously observed, CR attenuated footpad edema in WT mice. This attenuation was significantly blocked in CORT-deficient CR-fed CRHKO mice. Replacement of CORT in CR-fed CRHKO mice to the elevated levels observed in CR-fed WT mice, but not to the levels observed in AL-fed WT mice, restored the anti-inflammatory effect of CR. These results indicate that the hyperadrenocorticism of CR contributes to the anti-inflammatory action of CR, which may in turn contribute to its life-extending actions.

Pharmacological manipulations of interval timing using the peak procedure in male C3H mice.

RATIONALE: Timing deficits are characteristic of developmental and neurodegenerative disorders that are accompanied by cognitive impairment. A prominent theory of this interval timing posits an internal clock whose pace is modulated by the neurotransmitter dopamine. OBJECTIVES: We tested two hypotheses about the pharmacology of interval timing in mice: (1) that general cognitive enhancers should increase, and cognitive disruptors should decrease temporal precision and (2) that acutely elevated dopamine should speed this internal clock and produce overestimation of elapsing time. MATERIALS AND METHODS: C3H mice were tested in the peak procedure, a timing task, following acute administration of two putative cognitive enhancers (atomoxetine and physostigmine), two cognitive disruptors (scopolamine and chlordiazepoxide [CDP]), or two dopamine agonists (D: -amphetamine and methamphetamine). RESULTS: The first hypothesis received strong support: temporal precision worsened with both cognitive disruptors, but improved with both cognitive enhancers. The two dopamine agonists also produced underestimation of elapsing time-congruent with the slowing of an internal clock and inconsistent with a dopamine-driven clock. CONCLUSION: Our results suggest that interval timing has potential as an assay for generalized cognitive performance and that the dopamine-clock hypothesis needs further refinement.

Processes for design, construction and utilisation of arrays of light-emitting diodes and light-emitting diode-coupled optical fibres for multi-site brain light delivery.

Optogenetics enables light to be used to control the activity of genetically targeted cells in the living brain. Optical fibers can be used to deliver light to deep targets, and LEDs can be spatially arranged to enable patterned light delivery. In combination, arrays of LED-coupled optical fibers can enable patterned light delivery to deep targets in the brain. Here we describe the process flow for making LED arrays and LED-coupled optical fiber arrays, explaining key optical, electrical, thermal, and mechanical design principles to enable the manufacturing, assembly, and testing of such multi-site targetable optical devices. We also explore accessory strategies such as surgical automation approaches as well as innovations to enable low-noise concurrent electrophysiology.

Noninvasive optical inhibition with a red-shifted microbial rhodopsin.

Optogenetic inhibition of the electrical activity of neurons enables the causal assessment of their contributions to brain functions. Red light penetrates deeper into tissue than other visible wavelengths. We present a red-shifted cruxhalorhodopsin, Jaws, derived from Haloarcula (Halobacterium) salinarum (strain Shark) and engineered to result in red light-induced photocurrents three times those of earlier silencers. Jaws exhibits robust inhibition of sensory-evoked neural activity in the cortex and results in strong light responses when used in retinas of retinitis pigmentosa model mice. We also demonstrate that Jaws can noninvasively mediate transcranial optical inhibition of neurons deep in the brains of awake mice. The noninvasive optogenetic inhibition opened up by Jaws enables a variety of important neuroscience experiments and offers a powerful general-use chloride pump for basic and applied neuroscience.

Strategies for designing an efficient insurance fertility benefit: a 21st century approach.

Creating a 21st century insurance benefit for infertility should be cost effective. Savings can be realized by eliminating hidden infertility costs, eliminating payments for ineffective treatments, and providing coverage for effective 21st century treatments, thus reducing costs associated with iatrogenic multiple pregnancies. The new benefit allows patients to attempt 21st century forms of infertility treatments while being managed by certified infertility providers. Industry and insurance carriers might save money by examination and implementation of this concept.

Acquisition of peak responding: what is learned?

We investigated how the common measures of timing performance behaved in the course of training on the peak procedure in C3H mice. Following fixed interval (FI) pre-training, mice received 16 days of training in the peak procedure. The peak time and spread were derived from the average response rates while the start and stop times and their relative variability were derived from a single-trial analysis. Temporal precision (response spread) appeared to improve in the course of training. This apparent improvement in precision was, however, an averaging artifact; it was mediated by the staggered appearance of timed stops, rather than by the delayed occurrence of start times. Trial-by-trial analysis of the stop times for individual subjects revealed that stops appeared abruptly after three to five sessions and their timing did not change as training was prolonged. Start times and the precision of start and stop times were generally stable throughout training. Our results show that subjects do not gradually learn to time their start or stop of responding. Instead, they learn the duration of the FI, with robust temporal control over the start of the response; the control over the stop of response appears abruptly later.