Rhesus macaque brain morphometry: a methodological comparison of voxel-wise approaches.

Voxel-based morphometry studies have become increasingly common in human neuroimaging over the past several years; however, few studies have utilized this method to study morphometry changes in non-human primates. Here we describe the application of voxel-wise morphometry methods to the rhesus macaque (Macaca mulatta) using the 112RM-SL template and priors (McLaren et al. (2009) [42]) and as an illustrative example we describe age-associated changes in grey matter morphometry.

A population-average MRI-based atlas collection of the rhesus macaque.

Magnetic resonance imaging (MRI) studies of non-human primates are becoming increasingly common; however, the well-developed voxel-based methodologies used in human studies are not readily applied to non-human primates. In the present study, we create a population-average MRI-based atlas collection for the rhesus macaque (Macaca mulatta) that can be used with common brain mapping packages such as SPM or FSL. In addition to creating a publicly available T1-weighted atlas (http://www.

fMRI activation during episodic encoding and metacognitive appraisal across the lifespan: risk factors for Alzheimer's disease.

In the present study, we used fMRI to examine the influence of age on two other known risk factors for Alzheimer's disease (AD), APOE genotype and parental history of AD (FH status), during episodic encoding (ENC) and metacognitive self-appraisal (SA) paradigms. These paradigms have previously been shown to evoke activity from brain regions that are implicated in AD. First we examined the effect of age across the adult lifespan (age 18-84 years) on cerebral activity in a large sample (n=231) of cognitively healthy individuals.

Sweet intake, sweet-liking, urges to eat, and weight change: relationship to alcohol dependence and abstinence.

Introduction: Linkages between alcohol dependence (AD) and abstinence and aspects of food ingestion and preference have been described in animals and humans, including (1) eating sweets decreases urges to drink alcohol; (2) preferences for highly sweet tastants is associated with alcohol dependence; and (3) food deprivation leads to increased alcohol intake.

Methods: We randomly assigned AD subjects in early abstinence to 3 different sets of dietary instructions (eat sweets for alcohol urges; eat a balanced diet; avoid sweets). We compared the groups on urges for alcohol, alcohol consumption, weight, and sweet preference at baseline, one, and six months.

Ceramide and cholesterol: possible connections between normal aging of the brain and Alzheimer's disease. Just hypotheses or molecular pathways to be identified?

Even though it is known that aging is the single most important risk factor for Alzheimer's disease (AD), there is a lack of information on the molecular pathway(s) that connect normal aging of the brain to this form of neuropathology. Because of the rise in average lifespan, the number of individuals that reach the seventh or eighth decade of life and become at high risk for AD is rapidly increasing. Current estimations predict that by 2050 about 45 to 50 million individuals will be affected by AD worldwide.

A TrkA-to-p75NTR molecular switch activates amyloid beta-peptide generation during aging.

Aging is the single most important risk factor for AD (Alzheimer's disease). However, the molecular events that connect normal aging to AD are mostly unknown. The abnormal accumulation of Abeta (amyloid beta-peptide) in the form of senile plaques is one of the main characteristics of AD.

Neuroprotective effects of female sex steroids in humans: current controversies and future directions.

Recent findings from the Women's Health Initiative (WHI) have raised considerable concern over prolonged use of opposed and unopposed oral conjugated equine estrogen (CEE), given the increased risk of serious adverse effects, including stroke and venous thromboembolic complications. Furthermore, results from the WHI Memory Study (WHIMS) indicated that over 5 years of therapy with Prempro impaired performance on global cognitive tests and nearly doubled the risk of dementia. These surprising findings were contradictory to cumulative evidence from basic science, epidemiological and some intervention studies suggesting hormone therapy was cardioprotective and could potentially reduce the risk of dementia.

Amyloid-beta-induced toxicity of primary neurons is dependent upon differentiation-associated increases in tau and cyclin-dependent kinase 5 expression.

It has previously been reported that amyloid-beta (Abeta) peptide is neurotrophic to undifferentiated but neurotoxic to differentiated primary neurons. The underlying reasons for this differential effect is not understood. Recently, the toxicity of Abeta to neurons was shown to be dependent upon the activation of cyclin-dependent kinase 5 (Cdk5), thought to promote tau phosphorylation that leads to cytoskeletal disruption, morphological degeneration and apoptosis.

Oxidized products of linoleic acid stimulate adrenal steroidogenesis.

Adrenal steroidogenesis is under complex control, and clinical observations suggest that not all regulators have been identified. We postulated that fatty acid oxidation products found in the diet or formed in the body could affect steroidogenesis. Linoleic acid is a prominent constituent of animal fat and is readily oxidized.

How should dysphagia care of older adults differ? Establishing optimal practice patterns.

An unprecedented demographic transformation is occurring as our population ages. Those older than age 65 represent the fastest growing segment of the population. Within this older group, approximately 10% to 30% of adults are estimated to have dysphagia, but true incidence and prevalence are unknown.

Cutaneous oral-motor reflexes of children with normal and disordered speech.

Cutaneous reflex responses in the human jaw-closing system to low-threshold, mechanical stimulation were investigated in 30 four- to six-year-old children with normal speech and in seven children with disordered speech. Responses of these children were smaller and less frequently observed than those of a seven- to eight-year-old group in an earlier study, suggesting that cutaneous oral-motor reflexes may develop with the acquisition of speech motor skills. Preliminary observations in a very small sample of speech-impaired children suggest that future work should explore the hypothesis that development of cutaneous oral reflexes is delayed in this group.

Early changes in tumor metabolism after treatment: the effects of stereotactic radiotherapy.

Four patients with intracranial neoplasms, two with malignant gliomas and two with brain metastases, were treated with stereotactic radiotherapy. Patients received between 15 and 27.5 Gray of photon irradiation to the central tumor target point; the 80% isodose line covered the periphery of the tumor as determined by contrast enhanced computed tomography.

Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) of brain tumors.

In summary, PET and SPECT are versatile imaging modalities capable of providing dynamic information regarding the metabolism and physiology of brain and brain tumor. PET and SPECT are useful adjuncts to MRI and CT scanning in the important clinical areas of presurgical estimations of tumor grade. In addition, PET can be used to differentiate tumor necrosis from recurrence noninvasively, which is important for patient management.

Changes in glucose uptake by malignant gliomas: preliminary study of prognostic significance.

Sequential positron emission tomographic scans with [18F]-2-fluorodeoxyglucose (PET-FDG) were performed on 14 patients with malignant gliomas. All patients had prior brain irradiation. Five patients received adjuvant eight-drugs-in-one-day chemotherapy (experimental subjects) and 9 did not (control subjects).

Immunoneutralization of corticotropin-releasing hormone prevents the diurnal surge of ACTH.

To determine whether CRH is required for the evening rise in plasma ACTH, rats were injected at 0800 hr with CRH antiserum (anti-CRH) or normal rabbit serum (NRS). Blood samples were taken through venous catheters at 0800 hr before treatment and at 1300, 1700, and 2100 hr. Plasma was assayed for immunoreactive ACTH and corticosterone.

Changes in mean plasma ACTH reflect changes in amplitude and frequency of secretory pulses.

ACTH is secreted in an episodic manner from the anterior pituitary. Unanesthetized rats with indwelling jugular and femoral venous cannulae were continuously bled and simultaneously infused with isotonic fluid by peristaltic pump. Two-minute blood samples were collected for up to five hours in 8 male rats.

Effects of calmodulin inhibitors on rabbit synoviocyte phospholipase A2.

The effect of calmodulin inhibitors on synoviocyte phospholipase A2 activity was evaluated. Cells were incubated with [3H]arachidonic acid after 24 hours to label phospholipids. [3H]prostaglandin E2 synthesis was stimulated by Salmonella minnesota lipopolysaccharide (100 micrograms/ml).