Generalized cue reactivity in dopamine neurons after opioids.

Cue reactivity is the maladaptive neurobiological and behavioral response upon exposure to drug cues and is a major driver of relapse. The leading hypothesis is that dopamine release by addictive drugs represents a persistently positive reward prediction error that causes runaway enhancement of dopamine responses to drug cues, leading to their pathological overvaluation compared to non-drug reward alternatives. However, this hypothesis has not been directly tested.

Scaling of smaller pyramidal neuron size and lower energy production in schizophrenia.

Background: Dorsolateral prefrontal cortex (DLPFC) dysfunction in schizophrenia appears to reflect alterations in layer 3 pyramidal neurons (L3PNs), including smaller cell bodies and lower expression of mitochondrial energy production genes. However, prior somal size studies used biased strategies for identifying L3PNs, and somal size and levels of energy production markers have not been assessed in individual L3PNs.

Study Design: We combined fluorescent in situ hybridization (FISH) of vesicular glutamate transporter 1 (VGLUT1) mRNA and immunohistochemical-labeling of NeuN to determine if the cytoplasmic distribution of VGLUT1 mRNA permits the unbiased identification and somal size quantification of L3PNs.

Efficacy of an Individually Tailored, Internet-Mediated Physical Activity Intervention in Older Adults: A Randomized Controlled Trial.

Objective: This study determined the effectiveness of an individually tailored, Internet-mediated physical activity (PA) intervention for increasing walking behavior in inactive older adults.

Method: This 12-week randomly controlled intervention divided participants ( N = 170) into three groups: control (CON, n = 51), pedometer only (PED, n = 62), and an individually tailored, Internet-mediated pedometer (TI-PED, n = 57) group. The PED group was instructed to increase weekly step count by 10% until 10,000 steps per day was achieved.

Isotemporal Substitution of Sedentary Behavior and Physical Activity on Function.

Unlabelled: The amount of time spent in sedentary behaviors (SB) progressively increases with age, while reducing time spent in light-intensity physical activity (LPA) and moderate- to vigorous-intensity physical activity (MVPA). These trajectories in PA and SB are linked to accelerated reductions in physical functioning.

Purpose: This study aimed to examine the association of substituting SB time with LPA and MVPA on physical function in older adults.

Individualized Estimation of Physical Activity in Older Adults with Type 2 Diabetes.

Purpose: Compare physical activity intensity in older adults with type 2 diabetes mellitus (T2DM) using individualized, relative cutpoints with standard, absolute cutpoints.

Methods: One hundred older adults with T2DM (68.9 ± 5.

A prospective examination of the impact of high levels of exercise training on sedentary behaviour.

Unlabelled: The aim of this study is to determine changes in sedentary behaviour in response to extensive aerobic exercise training. Participants included adults who self-selected to run a marathon. Sedentary behaviour, total activity counts and physical activity (PA) intensity were assessed (Actigraph GT3X) for seven consecutive days during seven assessment periods (-3, -2, and -1 month prior to the marathon, within 2 weeks of the marathon, and +1, +2, and +3 months after the marathon).

A positive association between active lifestyle and hemispheric lateralization for motor control and learning in older adults.

Physical activity (PA) is well known to have general health benefits for older adults, but it is unclear whether it can also positively affect brain function involved in motor control and learning. We have previously shown that interlimb transfer of visuomotor adaptation occurs asymmetrically in young adults, while that occurs symmetrically in older adults, which suggests that the lateralized function of each hemisphere during motor tasks is diminished with aging. Here, we investigated the association between the level of PA and hemispheric motor lateralization by comparing the pattern of interlimb transfer following visuomotor adaptation between physically active and inactive older adults.

Accuracy of uploadable pedometers in laboratory, overground, and free-living conditions in young and older adults.

Purpose: The purpose of this study was to examine the accuracy of uploadable pedometers to accurately count steps during treadmill (TM) and overground (OG) walking, and during a 24 hour monitoring period (24 hr) under free living conditions in young and older adults.

Methods: One hundred and two participants (n=53 aged 20-49 yrs; n=49 aged 50-80 yrs) completed a TM protocol (53.6, 67.

Comparison of the IPAQ-Short Form and accelerometry predictions of physical activity in older adults.

Older adult physical activity (PA) levels obtained from the International Physical Activity Questionnaire-Short Form (IPAQ) and accelerometry (ACC) were compared. Mean difference scores between accumulated or bout ACC PA and the IPAQ were computed. Spearman rank-order correlations were used to assess relations between time spent in PA measured from ACC and self-reported form of the IPAQ, and percentage agreement across measures was used to classify meeting or not meeting PA recommendations.

Prediction of body fat in older adults by time spent in sedentary behavior.

The purpose of the study was to determine the relationship between sedentary behavior (SB), physical activity (PA), and body fat (total, abdominal) or body size (body-mass index [BMI], waist circumference [WC]) in community-dwelling adults 50 yr old and over. This study included 232 ambulatory adults (50-87 yr, 37.4% ± 9.

A pilot randomized controlled trial evaluating motivationally matched pedometer feedback to increase physical activity behavior in older adults.

Background: Increasing physical activity (PA) levels in older adults represents an important public health challenge. The purpose of this study was to evaluate the feasibility of combining individualized motivational messaging with pedometer walking step targets to increase PA in previously inactive and insufficiently active older adults.

Methods: In this 12-week intervention study older adults were randomized to 1 of 4 study arms: Group 1--control; Group 2--pedometer 10,000 step goal; Group 3--pedometer step goal plus individualized motivational feedback; or Group 4--everything in Group 3 augmented with biweekly telephone feedback.

A Pilot Randomized Controlled Trial Evaluating Motivationally Matched Pedometer Feedback to Increase Physical Activity Behavior in Older Adults.

Background: Increasing physical activity (PA) levels in older adults represents an important public health challenge. The purpose of this study was to evaluate the feasibility of combining individualized motivational messaging with pedometer walking step targets to increase PA in previously inactive and insufficiently active older adults.

Methods: In this 12-week intervention study older adults were randomized to 1 of 4 study arms: Group 1-control; Group 2-pedometer 10,000 step goal; Group 3-pedometer step goal plus individualized motivational feedback; or Group 4-everything in Group 3 augmented with biweekly telephone feedback.

Estimating absolute and relative physical activity intensity across age via accelerometry in adults.

This study examined the predictive validity of accelerometers (ACC) to estimate physical activity intensity (PAI) across age and differences in intensity predictions when expressed in relative and absolute PAI terms. Ninety adults categorized into 3 age groups (20-29, 40-49, and 60-69 yr) completed a treadmill calibration study with simultaneous ACC (7164 Actigraph) and oxygen-consumption assessment. Results revealed strong linear relations between ACC output and measured PAI (R2 = .

Validity of Physical Activity Monitors in Assessing Energy Expenditure in Normal, Overweight, and Obese Adults.

A comparison of the validity of downloadable motion sensors, which use either a glass-enclosed magnetic reed proximity switch technology, a piezo-electric sensor accelerometer with a horizontal beam technology, or an internal pendulum based mechanism to determine energy expenditure (EE), across different body sizes does not exist. Therefore, the purpose of this study was to determine the validity of three different downloadable motion sensors to estimate EE during walking activity in normal weight, overweight and obese volunteers. Forty-eight participants completed this study.

The impact of body-mass index and steps per day on blood pressure and fasting glucose in older adults.

The purpose of this study was to investigate the combined impact of obesity and physical activity (PA) on the health of older adults. Pedometer-determined steps/d, body-mass index (BMI), resting blood pressure, and fasting glucose (FG) were assessed in 137 older adults (69.0 +/- 8.

Glucose control and walking in a multiethnic sample of older adults.

Background: Although walking is the most commonly reported physical activity by older adults, there is a paucity of data determining the relationship between objectively determined walking behavior and glucose dynamics in older adults.

Objective: This study was designed to investigate the relationship between objectively determined walking behavior and glucose control in a multiethnic sample of older adults.

Methods: Data were collected on 142 older adults (age 72.