Primacy and recency effects in hierarchical renewal in rats.

Previous studies on hierarchical resurgence produced mixed results regarding the order and magnitude of recurrence of responses trained initially (primacy effect) or more recently (recency effect). Although changes in contextual stimuli could explain such differences, in resurgence procedures contextual stimuli are not commonly presented, thus their effects on multiple operants trained sequentially remain unclear. Renewal procedures, in contrast, have been useful to determine the effects of exteroceptive contextual stimuli on response recurrence.

A graph-embedded topic model enables characterization of diverse pain phenotypes among UK biobank individuals.

Large biobank repositories of clinical conditions and medications data open opportunities to investigate the phenotypic disease network. We present a graph embedded topic model (GETM). We integrate existing biomedical knowledge graph information in the form of pre-trained graph embedding into the embedded topic model.

3D-printed operant chambers for rats: Design, assembly, and innovations.

Ten years ago, we started a project at the National Autonomous University of Mexico with the purpose of building custom-made operant conditioning chambers that could be used in research and laboratory courses. The focus was to reduce the cost and improve the flexibility of operant chambers by integrating advances in electronics and manufacturing processes such as 3D printing and laser-cutting technologies. With these technologies we designed and built customizable and reliable operant chambers for rats in which responses can be recorded using levers or photocells.

A functional polymorphism in the ATP-Binding Cassette B1 transporter predicts pharmacologic response to combination of nortriptyline and morphine in neuropathic pain patients.

Many genetic markers have been associated with variations in treatment response to analgesics, but none have been assessed in the context of combination therapies. In this study, the treatment effects of nortriptyline and morphine were tested for an association with genetic markers relevant to pain pathways. Treatment effects were determined for single and combination therapies.

Human pain genetics database: a resource dedicated to human pain genetics research.

The Human Pain Genetics Database (HPGDB) is a comprehensive variant-focused inventory of genetic contributors to human pain. After curation, the HPGDB currently includes 294 studies reporting associations between 434 distinct genetic variants and various pain phenotypes. Variants were then submitted to a comprehensive analysis.

Post-concussion symptoms and chronic pain after mild traumatic brain injury are modulated by multiple locus effect in the gene through the expression of antisense: A pilot prospective control study.

: Mild traumatic brain injury (mTBI) often results in post-concussion symptoms, chronic pain, and sleepiness. Genetic factors are thought to play an important role in poor prognosis. : The aims of this study are to (1) document the prevalence of pain and post-concussion symptoms in mTBI patients in acute and chronic phases (2) determine whether candidate genes predispose to post-concussive symptoms and pain.

Resurgence of response duration in human participants.

Previously reinforced responses can reappear when reinforcement is withdrawn from current responding. This is known as resurgence. Although resurgence of response topography, spacing, and patterns over time has been demonstrated, there is no evidence of resurgence of response duration.

Pain with traumatic brain injury and psychological disorders.

Traumatic brain injury (TBI) is the cause for long-term disability in more than 3 million patients in the US alone, with chronic pain being the most frequently reported complain. To date, predisposing mechanisms for chronic pain in TBI patients are largely unknown. Psychological disorders, including post-traumatic stress disorder, depression and anxiety following TBI are commonly reported comorbidities to post-traumatic pain.

α4-Containing GABA(A) Receptors are Required for Antagonism of Ethanol-Induced Motor Incoordination and Hypnosis by the Imidazobenzodiazepine Ro15-4513.

Alcohol (ethanol) is widely consumed for its desirable effects but unfortunately has strong addiction potential. Some imidazobenzodiazepines such as Ro15-4513 are able to antagonize many ethanol-induced behaviors. Controversial biochemical and pharmacological evidence suggest that the effects of these ethanol antagonists and ethanol are mediated specifically via overlapping binding sites on α4/δ-containing GABA(A)-Rs.

Identification of anesthetic binding sites on human serum albumin using a novel etomidate photolabel.

We have synthesized a novel analog of the general anesthetic etomidate in which the ethoxy group has been replaced by an azide group, and which can be used as a photolabel to identify etomidate binding sites. This acyl azide analog is a potent general anesthetic in both rats and tadpoles and, as with etomidate, is stereoselective in its actions, with the R(+) enantiomer being significantly more potent than the S(-) enantiomer. Its effects on alpha1beta2gamma2s GABA(A) receptors expressed in HEK-293 cells are virtually indistinguishable from the parent compound etomidate, showing stereoselective potentiation of GABA-induced currents, as well as direct mimetic effects at higher concentrations.

Expansion of gas bubbles by nitrous oxide and xenon.

Background: Nitrous oxide is well known to expand gas bubbles trapped in enclosed spaces and is contraindicated in situations where this may occur. Xenon, an anesthetic gas with similar physical properties to nitrous oxide, is also likely to expand gas bubbles, and it has been predicted that microbubbles in the circulation may expand dramatically when exposed to xenon. Because of the possibility that xenon will be used during cardiopulmonary bypass surgery, a procedure that is likely to introduce microbubbles into the circulation, the authors reinvestigated the extent to which xenon expands gas bubbles in aqueous solution.