Enhanced Retention In The Passive-Avoidance Task By 5-HT1A Receptor Blockade Is Not Associated With Increased Activity Of The Central Nucleus Of The Amygdala

The effect of blockade of S-HT1A receptors was investigated on (1) retention in a mildly aversive passive-avoidance task, and (2) spontaneous single-unit activity of central nucleus of the amygdala (CeA) neurons, a brain site implicated in modulation of retention. Systemic administration of the selective S-HT1A antagonist NAN-190 immediately after training markedly-and dose-dependently-facilitated retention in the passive-avoidance task; enhanced retention was time-dependent and was not attributable to variations in wattages of shock received by animals. Systemic administration of NAN-190 had mixed effects on spontaneous single-unit activity of CeA neurons recorded extracellularly in vivo; microiontophoretic application of S-HT, in contrast, consistently and potently suppressed CeA activity. The present findings-that S-HT1A receptor blockade by NAN-190 (1) enhances retention in the passive-avoidance task, and (2) does not consistently increase spontaneous neuronal activity of the CeA-provide evidence that a serotonergic system tonically inhibits modulation of retention in the passive-avoidance task through activation of the S-HT1A receptor subtype at brain sites located outside the CeA

Human papillomavirus DNA in aerodigestive squamous carcinomas demonstrated by means of in situ hybridisation

A series of 10 oesophageal and 10 laryngeal squamous carcinomas was examined by means of immuno cytochemistry and in situ DNA hybridisation to demonstrate human papillomavirus (HPV) infection. Changes in the epithelium adjacent to the carcinoma were found in 5 of 10 oesophageal and 7 of 10 laryngeal carcinomas. Viral antigens could not be detected with imInunocytochemistry in any of the specimens. HPV 6, 11 and 16 were detected in 3 oesophageal specimens. In one of these, HPV 16 was detected in normal as well as malignant cells. HPV 7 was detected for the first time in a laryngeal carcinoma. Our results confirm previous reports of possible HPV involvement in the pathogenesis of aerodigestive carcinomas

Beta-Adrenergic Receptor Blockade By Propranolol Enhances Retention In A Multitrial Passive-Avoidance Procedure

The effect of beta -adrenergic receptor blockade on retention in a mildly aversive passive-avoidance procedure was investigated. Rats were given passive-avoidance training-1 trial per day for 4 days-and were administered saline, the centrally and peripherally acting beta -adrenergic blocker propranolol (4 or 10 mg/kg ip), or the peripherally acting P-adrenergic blocker sotalol (4 or 10 mg/kg ip) immediately or 2 hr after the Ist trial. Enhanced retention occurred only with the higher dose (10 mg/kg) of propranolol and only when it was administered immediately after training. The enhanced retention produced by propranolol is discussed in terms of opposing, regionally specific actions of beta -adrenergic receptor-mediated neural circuits on modulation of memory

Rupture of multiple parallel molecular bonds under dynamic loading

Biological adhesion often involves several pairs of specific receptor-ligand molecules. Using rate equations, we study theoretically the rupture of such multiple parallel bonds under dynamic loading assisted by thermal activation. For a simple generic type of cooperativity, both the rupture time and force exhibit several different scaling regimes. The dependence of the rupture force on the number of bonds is predicted to be either linear, like a square root or logarithmic.Comment: 8 pages, 2 figure

An Effective Membrane Model of the Immunological Synapse

The immunological synapse is a patterned collection of different types of receptors and ligands that forms in the intercellular junction between T Cells and antigen presenting cells (APCs) during recognition. The synapse is implicated in information transfer between cells, and is characterized by different spatial patterns of receptors at different stages in the life cycle of T cells. We obtain a minimalist model that captures this experimentally observed phenomenology. A functional RG analysis provides further insights.Comment: 6 pages, 3 figures, submitted for publicatio

Landscape structure planning and the urban forest in polycentric city regions

© Published under licence by IOP Publishing Ltd. The World is continuing to urbanise at an increasing and some say alarming rate, and although urbanism is not uniform in all countries, without a doubt the 21 st century is the century of the Polycentric City Region. By the year 2007, for the first time in history, the world hosted more urban dwellers than rural, and in order to deal with this urban expansion in an environmentally acceptable way, the concept of the "sustainable compact city" was advocated. There is now an increasing canon of research however that suggests that such cities may not be quite as sustainable as they are claimed to be. As a consequence, the concept of "urban green infrastructure", which includes the concept of urban forestry, is being incorporated into new thinking on the landscape structure planning of expanding cities and city regions to ensure that they provide an acceptable quality of life for their inhabitants. The environmental, economic, social, health, well-being and cultural benefits that emanate from such an approach to promoting resilient landscape structure planning are considerable. Such an approach to landscape structure planning is well-able to repair the beneficial relationship that people once had with their landscapes, a relationship that has arguably suffered as our scientific and economic cultures have tended to gain the upper hand in the post-industrial times in which we live. Human beings have had a long, deep, cultural relationship with trees, woodlands and the landscape - a relationship which transcends national cultures. The use of the term "landscape" does not refer to the rather shallow modern concept of 'the landscape as a view", but to the more fundamental concept of "landscape as the composition of our world". Thus it refers to both urban, peri-urban and rural areas, and the urban forest is the prime spatial articulator of a landscape structure plan. Although the words "forest" and "forestry" are now generally understood to be connected with trees, the words have arguably been derived from the Latin word "foris", meaning "out of doors" or "unenclosed land" (Porteous, 1928 p34). Thus urban forestry could be described as the "urban out of doors". This presentation will consider the benefits that can be achieved from developing a viable urban forest structure as the backbone of a polycentric city region landscape structure plan. It will focus upon the Leeds Polycentric City Region in the UK and its emerging Leeds City Region Green and Blue Infrastructure Strategy 2017 - 2036 as a case study

Stress-Dependent Impairment Of Passive-Avoidance Memory By Propranolol Or Naloxone

Previous work has shown that the effect of opioid-receptor blockade on memory modulation is critically dependent upon the intensity of stress. The current study determined the effect of adrenergic-receptor blockade on memory modulation under varied levels of stress and then compared the effect of adrenergic-receptor blockade under intense stress to that of a) opioid-receptor blockade and b) concurrent opioid- and adrenergic-receptor blockade. In the first experiment, the β-adrenergic-receptor blocker propranolol impaired retention in the passive-avoidance procedure when administered immediately after exposure to intense stress (passive-avoidance training followed by swim stress) but not mild stress (passive-avoidance training alone). In the second experiment, while separate administration of either propranolol or the opioid-receptor blocker naloxone immediately after exposure to intense stress impaired retention, the combined administration of propranolol and naloxone failed to do so. These findings demonstrate that the effect of β-adrenergic-receptor blockade or opioid-receptor blockade on memory modulation in the passive-avoidance procedure is dependent upon the intensity of stress, and suggest that concurrent inactivation of endogenous adrenergic- and opioid-based memory modulation systems under stressful conditions is protective of memory