In vivo dual intra- and extracellular recordings suggest bidirectional coupling between CA1 pyramidal neurons.

Spikelets, small spikelike membrane potential deflections, are prominent in the activity of hippocampal pyramidal neurons in vivo. The origin of spikelets is still a source of much controversy. Somatically recorded spikelets have been postulated to originate from dendritic spikes, ectopic spikes, or spikes in an electrically coupled neuron.

Tactile experience shapes prey-capture behavior in Etruscan shrews.

A crucial role of tactile experience for the maturation of neural response properties in the somatosensory system is well established, but little is known about the role of tactile experience in the development of tactile behaviors. Here we study how tactile experience affects prey capture behavior in Etruscan shrews, Suncus etruscus. Prey capture in adult shrews is a high-speed behavior that relies on precise attacks guided by tactile Gestalt cues.

Trypanosoma brucei 20 S editosomes have one RNA substrate-binding site and execute RNA unwinding activity.

Editing of mitochondrial pre-mRNAs in African trypanosomes generates full-length transcripts by the site-specific insertion and deletion of uridylate nucleotides. The reaction is catalyzed by a 0.8 MDa multienzyme complex, the editosome.

Friction-based stabilization of juxtacellular recordings in freely moving rats.

Virtually nothing is known about the activity of morphologically identified neurons in freely moving mammals. Here we describe stabilization and positioning techniques that allow juxtacellular recordings from labeled single neurons in awake, freely moving animals. This method involves the use of a friction-based device that allows stabilization of the recording pipette by friction forces.

Weak and nondiscriminative responses to conspecifics in the rat hippocampus.

Little is known about how hippocampal neurons in rodents respond to and represent conspecifics. To address this question, we let rats interact while quantifying hippocampal neuronal activation patterns with extracellular recordings and immediate-early gene (c-Fos) expression. A total of 319 single putative pyramidal neurons was recorded in dorsal hippocampus.

Combining sparseness and smoothness improves classification accuracy and interpretability.

Sparse logistic regression (SLR) has been shown to be a useful method for decoding high-dimensional fMRI and MEG data by automatically selecting relevant feature dimensions. However, when applied to signals with high spatio-temporal correlations, SLR often over-prunes the feature space, which can result in overfitting and weight vectors that are difficult to interpret. To overcome this problem, we investigate a modification of ℓ₁-normed sparse logistic regression, called smooth sparse logistic regression (SSLR), which has a spatio-temporal "smoothing" prior that encourages weights that are close in time and space to have similar values.

Cytoarchitecture, areas, and neuron numbers of the Etruscan shrew cortex.

The Etruscan shrew, Suncus etruscus, is one of the smallest mammals. Etruscan shrews can recognize prey shape with amazing speed and accuracy, based on whisker-mediated tactile cues. Because of its small size, quantitative analysis of the Etruscan shrew cortex is more tractable than in other animals.

The many facets of facial interactions in mammals.

Facial interactions are prominent behaviors in primates. Primate facial signaling, which includes the expression of emotions, mimicking of facial movements, and gaze interactions, is visually dominated. Correspondingly, in primate brains an elaborate network of face processing areas exists within visual cortex.

Treatment outcomes for methamphetamine users: California Proposition 36 and comparison clients.

Methamphetamine (meth) is a major drug of abuse in California and several other states, particularly among criminal offender populations. Over the past decade, substance abuse treatment systems have had to adapt to and accommodate the increasing needs of meth users and, in California, deal with the impact of Proposition 36, which has resulted in a greater number of criminal offenders entering the treatment system. This study examines selected treatment performance and outcome indicators for California Proposition 36 offenders entering substance abuse treatment for meth use and compares their performance and outcomes to other subgroups of California treatment clients differentiated by whether or not they were admitted to treatment through Proposition 36 and whether or not their primary substance was meth.

Red antenna states of Photosystem I trimers from Arthrospira platensis revealed by single-molecule spectroscopy.

Single-molecule fluorescence spectroscopy at 1.4K was used to investigate the spectral properties of red (long-wavelength) chlorophylls in trimeric Photosystem I (PSI) complexes from the cyanobacterium Arthrospira platensis. Three distinct red antenna states could be identified in the fluorescence spectra of single PSI trimers from A.

Social facial touch in rats.

We know much about how rats use their whiskers to discriminate simple tactile properties, but little about how they are used in natural settings. Here we studied whisker motion during social interactions between rats in order to gain a better understanding of natural whisker use in this model system for sensorimotor integration. In the first set of experiments, an intruder was placed in a second rat's home cage.

Movement, confusion, and orienting in frontal cortices.

In this issue, two studies, by Ehrlich et al. and Hill et al., address the role of the frontal motor cortices in behavior of the rat and suggest a potential role for this structure in high-level control of diverse behaviors.

The neurobiology of Etruscan shrew active touch.

The Etruscan shrew, Suncus etruscus, is not only the smallest terrestrial mammal, but also one of the fastest and most tactile hunters described to date. The shrew's skeletal muscle consists entirely of fast-twitch types and lacks slow fibres. Etruscan shrews detect, overwhelm, and kill insect prey in large numbers in darkness.

Methamphetamine: here we go again?

Following more than two decades of generally increasing trends in the use and abuse of methamphetamine in certain parts of the country, prevalence indicators for the drug began to decrease in the mid-2000's-but was this decrease signaling the end of the "meth problem"? This paper has compiled historical and recent data from supply and demand indicators to provide a broader context within which to consider the changes in trends over the past half decade. Data suggest supply-side accommodation to changes in precursor chemical restrictions, with prevalence indicators beginning to attenuate in the mid-2000's and then increasing again by 2009-2010. Results support the need for continuing attention to control and interdiction efforts appropriate to the changing supply context and to continuing prevention efforts and increased number of treatment programs.

Fluorescence of the various red antenna states in photosystem I complexes from cyanobacteria is affected differently by the redox state of P700.

Photosystem I of cyanobacteria contains different spectral pools of chlorophylls called red or long-wavelength chlorophylls that absorb at longer wavelengths than the primary electron donor P700. We measured the fluorescence spectra at the ensemble and the single-molecule level at low temperatures in the presence of oxidized and reduced P700. In accordance with the literature, it was observed that the fluorescence is quenched by P700(+).

Evidence for direct binding of glycerol to photosystem I.

The interaction between glycerol and photosystem I (PSI) was investigated using low temperature single-molecule spectroscopy. PSI complexes were dissolved in three different solutions: in buffer solution, in 66% glycerol/buffer solution, and in 66% glycerol/buffer solution that was afterwards diluted by buffer; the final glycerol concentration was <1‰. Mean fluorescence spectra and intercomplex heterogeneity of PSI complexes in 66% glycerol/buffer solution and in the re-diluted solution show high similarity, but differ from complexes in buffer solution indicating that the glycerol concentration is not the determining factor modifying the spectral properties.

Microcircuits of functionally identified neurons in the rat medial entorhinal cortex.

Extracellular recordings have elucidated spatial neural representations without identifying underlying microcircuits. We labeled neurons juxtacellularly in medial entorhinal cortex of freely moving rats with a friction-based, pipette-stabilization system. In a linear maze novel to the animals, spatial firing of superficial layer neurons was reminiscent of grid cell activity.

Effect of glycerol and PVA on the conformation of photosystem I.

Single-molecule spectroscopy at cryogenic temperatures was used to examine the impact of buffer solution, glycerol/buffer mixtures (25% and 66%), and poly(vinyl alcohol) (PVA) films on the conformation of photosystem I (PSI) from Thermosynechoccocus elongatus. PSI holds a number of chromophores embedded at different places within the protein complex that show distinguishable fluorescence at low temperatures. The fluorescence emission from individual complexes shows inter- and intracomplex heterogeneity depending on the solution wherein PSI was dissolved.

Intracellular determinants of hippocampal CA1 place and silent cell activity in a novel environment.

For each environment a rodent has explored, its hippocampus contains a map consisting of a unique subset of neurons, called place cells, that have spatially tuned spiking there, with the remaining neurons being essentially silent. Using whole-cell recording in freely moving rats exploring a novel maze, we observed differences in intrinsic cellular properties and input-based subthreshold membrane potential levels underlying this division into place and silent cells. Compared to silent cells, place cells had lower spike thresholds and peaked versus flat subthreshold membrane potentials as a function of animal location.

Active touch during shrew prey capture.

Although somatosensation in multiple whisker systems has been studied in considerable detail, relatively little information is available regarding whisker usage and movement patterns during natural behaviors. The Etruscan shrew, one of the smallest mammals, relies heavily on its whisker system to detect and kill its highly mobile insect prey. Here, we tracked whisker and body motion during prey capture.

Self-report of Longitudinal Substance Use: A Comparison of the UCLA Natural History Interview and the Addiction Severity Index.

Reliance on self-report of alcohol and drug use behavior is typical among studies of substance abusers. Few studies have compared different instruments assessing frequency of drug use over long periods of time to compare findings and determine if the pattern of use is shown to be similar across measures. In this study, the UCLA Natural History Interview (NHI) and the Addiction Severity Index (ASI) were administered at three annual follow-up periods (N = 301).

Prescription and over-the-counter drug treatment admissions to the California public treatment system.

Prescription and over-the-counter (OTC) drug abuse has become a focal point of public health policy, prevention, and control efforts. Adolescents represent one of the fastest growing segments of the general population abusing prescription and OTC drugs as represented by national surveys. This article reports on treatment admission data to the California addiction public system for prescription and OTC drugs among two age subgroups: adolescents 12-17 years and adults 18 years and older.

Improving the accountability of California's public substance abuse treatment system through the implementation of performance models.

Improving the care for individuals with substance use disorders is a national health policy priority. Like other parts of the health care system, the addiction field is under pressure for higher accountability-more efficient use of treatment resources, the delivery of quality services, and the production of positive client outcomes. This introductory article highlights the importance of the collection of articles being published in this special issue as they describe California's efforts toward making the alcohol and drug (AOD) treatment system more accountable and effective.