Aging results in a general decline in the response to external insults, including acute inflammatory challenges. In young animals, the inflammatory response requires activation of the sympathetic system, including neurotransmitters such as ATP, and catecholamines (epinephrine and norepinephrine). To test whether aging affects activation of this axis, and whether this ...

Changes in the levels of gamma-aminobutyric acid (GABA) are known to occur in different parts of the brain during aging. In our study we attempted to define the effect that aging has on glutamate decarboxylase (GAD), the key enzyme in the synthesis of GABA, in the central parts of the ...

We examined the effect of age, mass and the presence of the pons on the longevity (length of time spontaneous respiratory-related activity is produced) of brainstem-spinal cord preparations of neonatal rodents (rats and hamsters) and the level of oxygenation in the medulla respiratory network in these preparations. We found the ...

Intracerebral hemorrhage (ICH) usually affects older humans but almost no experimental studies have assessed aged animals. We address how aging alters inflammation, neuron death and lesion resolution after a hemorrhage in the rat striatum. In the normal aged brain, microglia displayed a 'dystrophic' phenotype, with shorter cellular processes and large ...

The evolution with ageing of insulin resistance, body weight (BW) and mean arterial pressure (MAP) was studied in a group of Zucker fatty rats (ZFRs, n = 22), between 7 and 16 weeks of age, compared with an age-matched control group of Zucker lean rats (ZLRs, n = 22). The ...

The kinetics of albendazole metabolites and albendazole sulphoxide enantiomers were studied in 2- and 14-month-old female and male goats, after a single oral dose administration (10mg/kg) of an albendazole formulation. Blood samples from the jugular vein were collected at 0.5, 1, 2, 4, 6, 8, 10, 12, 16, 20, 24, ...

The aim of the present work was to obtain a quantitative evaluation of post-traumatic regeneration of nerve cells in the superior cervical ganglion (SCG) by measuring the ratio of the number of neurons (N) in the ganglion to the number of preganglionic myelinated fibers (F) in the cervical sympathetic trunk ...

Age-dependent threshold and superthreshold behaviors of ultrasound-induced lung hemorrhage were investigated with one hundred ten 12.6 +/- 0.8-d-old rats, one hundred ten 22.9 +/- 0.8-d-old rats, and one hundred 57.7 +/- 3.9-d-old rats. Exposure conditions were: 2.8 MHz, 10-s exposure duration, 1-kHz pulse repetition frequency and 1.3-mus pulse duration. The ...

Astrocytes perform neuron-supportive tasks, repair and scarring process in the central nervous system. In this study, we observed glial fibrillary acidic protein (GFAP), a marker for astrocytes, immunoreactivity in the dentate gyrus and hippocampus proper (CA1-3 region) of adult (2-3 years of age) and aged (10-12 years of age) dogs. ...

Evidence suggests that ageing is a major risk factor for cardiac dysfunction. Interactions between advanced glycation endproducts (AGEs) and the receptor for AGEs (RAGE) are known to cause chronic cellular activation, including activation of nuclear factor-kappaB (NF-kappaB), which has been implicated as a causal factor in the ageing process. To ...

Age-related and aged memory deficit changes in Nestin-immunoreactive (Nestin-IR) neurons were studied following recent evidence of distinct Nestin-IR neurons within adult rat basal forebrain. Morris water maze task assessed spatial learning capacity of 3- and 24-month rats (aged-impaired and aged-unimpaired groups). Nestin-IR neuron distributional and morphological features were investigated by ...

Supplemental choline in the maternal diet produces a lasting enhancement in memory in offspring that resists age-related decline and is accompanied by neuroanatomical, neurophysiological and neurochemical changes in the hippocampus. The present study was designed to examine: 1) if prenatal choline supplementation alters behaviors that contribute to risk or resilience ...

A multi-age rat model was evaluated to identify a potential age-related difference in kidney injury following administration of cisplatin (CP). Different age groups of Wistar rats (aged 3, 7, 11 and 24 weeks) were given CP intraperitoneally (6 mg/kg) and sacrificed 6 days thereafter. CP-induced nephrotoxicity caused significant decreases in ...

We describe neuronal density, neuroplasticity and vascular remodelling and their association with spatial memory in young (4-6 months), middle-aged (9-11 months) and aged (18-20 months) rats of both genders. The neuronal density was reduced in the hippocampus of middle-aged and aged rats, particularly in male rats. However the loss of ...

In the search for animal models of human geriatric depression, we found that operant extinction of escape from water results in the expression of immobility in different age groups, indicative of behavioral "despair", which was also associated with the resistance-to-extinction (RTE) expressed by these animals. With respect to the neurotrophin ...

Age-dependent alterations in the induction of long-term potentiation (LTP) are well documented, providing a likely neural basis for memory decline associated with aging. Studies of neural plasticity are also important to understand the neural basis of individual differences in aging, ranging from significant cognitive impairment to preservation of function on ...

The ability to make advantageous choices among outcomes that differ in magnitude, probability, and delay until their arrival is critical for optimal survival and well-being across the lifespan. Aged individuals are often characterized as less impulsive in their choices than their young adult counterparts, demonstrating an increased ability to forgo ...

Synaptic dysfunction is thought to contribute to age-related learning impairments. Detailed information regarding the presence of silent synapses and the strength of functional ones through advanced aging, however, is lacking. Here we used paired-pulse minimal stimulation techniques in CA1 stratum radiatum to determine whether the amplitude of spontaneous and evoked ...

Since there is still debate about the ability of the aged liver to regenerate, we compared some aspects of this response in young, adult and old rodents. 2, 6, 12 and 19-month-old rats were intraperitoneally injected with CCl4 (3 mg/kg) or left untreated (CT) and killed either 2 h (group ...

Background/Aims: Morphofunctional studies suggest that the liver, compared with other organs, ages fairly well. Its success is ascribable to its lasting ability to regenerate, even if the potential of the cells to replicate progressively declines with age. The aim of this study was to analyze some aspects of the early ...

Most spinal cord injuries (SCI) occur in young adults. In the past few decades however, the average age at time of SCI and the percentage of injuries in persons over the age of 60 have increased. Studies have shown that there is an age-associated delay in the rate of remyelination ...

Motor function declines with increasing adult age. Proper regulation of the balance between dopamine (DA) and acetylcholine (ACh) in the striatum has been shown to be fundamentally important for motor control. Although other factors can also contribute to this age-associated decline, a decrease in the concentration and binding potential of ...

Incidence of prostatic diseases increases dramatically with age which may be related to a decline in androgen support. However, the key mechanisms underlying prostate aging remain unclear. In the present study, we investigated the aging process in the ventral prostate (VP) of Noble rats by identifying differentially expressed prostate proteins ...

The aim of this study was to investigate changes in astrocyte density, morphology, proliferation and apoptosis occurring in the central nervous system during physiological aging. Astrocytes in retinal whole-mount preparations from Wistar rats aged 3 (young adult) to 25 months (aged) were investigated qualitatively and quantitatively following immunofluorohistochemistry. Glial fibrillary ...

Neuronal activity underlying the pulsatile secretion of GnRH remains poorly understood, as does the endogenous generation of such activity. It is clear that changes at the level of the hypothalamus are taking place during reproductive aging, yet virtually nothing is known about GnRH neuronal physiology in aging and postreproductive animals. ...

There has been ongoing controversy as to whether selective serotonin reuptake inhibitors (SSRIs) exhibit the same antidepressant efficacy and risk profile within different age groups. Although the etiology of such potential differences is currently not clear, age-dependent differences in the rate of hippocampal neurogenesis offer one possibility. In the current ...

BACKGROUND AND OBJECTIVES: Pentobarbital and ketamine are commonly used in animal experiments, including studies on the effects of ageing on the central nervous system. The electroencephalogram is a sensitive measure of brain activity. The present study investigated, under anaesthesia induced by the two drugs, whether cortical electroencephalogram in aged rats ...

Polyamines putrescine, spermidine and spermine are positively charged aliphatic amines and have important roles in maintaining normal cellular function, regulating neurotransmitter receptors and modulating learning and memory. Recent evidence suggests a role of putrescine in hippocampal neurogenesis, that is significantly impaired during aging. The present study measured the polyamine levels ...

The practice of regular exercise is indicated to prevent some motility disturbances in the gastrointestinal tract, such as constipation, during aging. The motility alterations are intimately linked with its innervations. The goal of this study is to determine whether a program of exercise (running on the treadmill), during 6 months, ...

Aging and acoustic trauma may result in partial peripheral deafferentation in the central auditory pathway of the mammalian brain. In accord with homeostatic plasticity, loss of sensory input results in a change in pre- and postsynaptic GABAergic and glycinergic inhibitory neurotransmission. As seen in development, age-related changes may be activity ...

The incidence of chronic renal disease in women increases with aging, especially after menopause, suggesting that loss of sex hormones may contribute to the development and progression of renal disease. However, the mechanisms by which sex hormones, particularly estrogens, contribute to the disease process are unclear. The present study examined ...

GFR falls with aging in humans and rats due to renal vasoconstriction and structural damage. The rate of deterioration is influenced by race/genetic background, environment, and sex, with females protected. Part of the female advantage relates to protective effects of estrogens. There is little information on impact of aging on ...

INTRODUCTION: Age effects on orthodontically induced periodontal vascular reactions have not been studied. The aim of the present study was to test the hypothesis that prolonged tooth movement induces age-related increases in periodontal vascularity. METHODS: A standardized orthodontic appliance was placed in 2 groups of 30 rats aged 6 weeks ...

We investigated developmental changes in myelin formation in the prefrontal cortex and the hippocampus, and behavioral effects of early weaning in Wistar rats. Early-weaned rats showed decreased numbers of open-arm entries in an elevated plus-maze in both sexes at 4 weeks old; this effect persisted in males, but ceased in ...

This study determined the haematological profiles of Sprague-Dawley (SD) outbred albino rats of both sexes and diferent age sets bred and maintained at the Faculty of Veterinary Medicine Laboratory Animal Unit, University of Nigeria, Nsukka, Nigeria. Erythrocyte counts (EC), packed cell volume (PCV), haemoglobin concentraton (Hb), erythrocyte sedimentation rate (ESR), ...

Glutamatergic transmission at central synapses undergoes activity-dependent and developmental changes. In the hippocampal dentate gyrus, the non-N-methyl d-aspartate (NMDA) receptor component of field excitatory postsynaptic potentials (fEPSPs) increases with age in Fischer-344 rats. This effect may not depend on the animal's activity or experience but could be part of the ...

This study aimed to evaluate the effects of regular physical activity on the morphology of the myenteric plexus of the duodenum in rats during the ageing process. To this end, 45 Wistar rats were divided into three groups: C (sedentary - 6 months old), S (sedentary - 12 months old) ...

At hippocampal synapses, repetitive synaptic stimulation (RSS) in the theta frequency range (3-12Hz) is associated with robust EPSP frequency facilitation (FF) and consequently, enhanced action potential (spike) generation and throughput. A complex, synaptically induced hyperpolarization (SIHP) is also triggered by synaptic activation, and a Ca(2+)-dependent afterhyperpolarization (AHP) is triggered above ...

With the aim of clarifying the aging properties of an animal model, the progress of occlusal tooth wear (OTW) of molars in male F344/N rats was monitored. Dried maxilla and mandible specimens from 61 male F344/N rats, aged 7 to >30 months, were used. The levels of OTW of all ...

OBJECTIVE: Study the effect of ephedrine on neural plasticity of hypoxic ischemic brain damaged (HIBD) in neonatal rats, and explore the underlying molecular mechanism. METHODS: 60 Sprats suffered from HIBD (7 days old) were randomly divided into ephedrine group, D-amphetamine (D-AMPH) group, cytidine triphosphate (CTP) group, ganglioside (GM1) group, and ...

OBJECTIVE: The increase of elderly population prompted growing research for the understanding of cerebral phenomena sustaining learning abilities, with inclusion of long-term potentiation (LTP)-like plasticity phenomena. Aim of the present study was to characterize LTP-like plasticity dependence on age and gender. METHODS: A LTP-like primary motor cortex plasticity inducing a ...

Aging is associated with peripheral vascular dysfunction. In vascular smooth muscle, cytochrome P450 4A (CYP4A) enzymes form the vasoconstrictor 20-hydroxyeicosatetraenoic acid (20-HETE). 20-HETE acts as an intracellular messenger to modulate vasoconstriction induced by various agonists, including the alpha1-adrenergic agonist phenylephrine (PE) and endothelin-1 (ET-1). Eicosanoids produced by CYP4A contribute to ...

Caloric restriction (CR) is a daily reduction of total caloric intake without a decrease in micronutrients or disproportionate reduction of any one dietary component. CR can increase lifespan reliably in a wide range of species and appears to counteract some aspects of the aging process throughout the body. The effects ...

Age-related inhibition of salivary secretion has been demonstrated in rats, and the nitric oxide (NO) present in the supraoptic nucleus (SON) and the medial septal area has been reported to play an inhibitory role in the regulation of salivary secretion. In the present study, we investigated the age-related changes occurring ...

We have previously described the transcriptional changes that occur in the hippocampal CA1 field of aged rats following a Morris Water Maze (MWM) training paradigm. In this report we proceed with the analysis of the dentate region from the same animals. Animals were first identified as age learning-impaired or age-superior ...

Introduction. Erectile dysfunction is a common problem in aged men; however, which vascular cavernosal alterations occur with age progression remain unclarified. Aim. Using cavernosal tissue from rats of various ages, we aimed to thoroughly assess erectile vascular-associated morphologic, immunohistological, and morphometric alterations during aging. Methods. Male Wistar rats were divided ...

General locomotor activity decreases with normal aging in animals and could be partially explained by decreases in neuronal function. Voltage-gated Na(+) channels are essential in initiating and propagating rapid electrical impulses underlying normal locomotor activity and behavior in animals. Isolation of mutations conferring temperature-sensitive (ts) paralysis has been an extremely ...

The effect of aging on microvascular density and plasticity in the rodent hippocampus, a brain region critically important for learning and memory, was investigated in F344xBN rats. Capillary density and angiogenesis were measured in three regions of the hippocampus in young and old rats and in old rats administered growth ...

The current study assessed neurotrophin protein levels in male and female rat brain tissues at four different ages ranging from postpuberty to senescence. In both sexes nerve growth factor (NGF) increased, and brain-derived neurotrophic factor (BDNF) decreased, from 4 to 24 months of age. Using a slightly older age for ...

In rat models of Parkinson's and Huntington's diseases, embryonic neural cells obtained from embryos of specified ages can be implanted into the brain to partially restore both physiology and function. However, in litters produced using overnight mating protocols (often from commercial suppliers), the embryonic age can be difficult to determine ...