Biomedical subjects

Barbara Webb

Publications and source records attributed to Barbara Webb.

5 recordsLinked to original sources

PubMed2003

Nerve growth factor and chronic ethanol treatment alter calcium homeostasis in developing rat septal neurons.

Chronic ethanol treatment (CET) during development produces cellular adaptations resulting in tolerance to the acute effects of ethanol (EtOH). The objectives of this study were to determine whether CET during the prenatal period (PCET) followed by a period of in vitro CET (PCET-CET) altered intracellular calcium [Ca(2+)](i) and produced tolerance to acute EtOH treatment (AET), and whether nerve growth factor (NGF) modulated the effects of PCET-CET in cultured developing rat septal neurons. Fetuses were obtained from EtOH-fed and sucrose-fed (diet-control) female rats. Neurons from PCET fetuses were cultured in the presence of NGF (+NGF) and 200 mg/dl (mg %) EtOH and diet-control cultures received NGF and no EtOH. PCET and diet-control cultures were then divided into two groups, +NGF and -NGF (withdrawn from NGF), and exposed acutely to one of five doses of EtOH during stimulation with potassium (K(+)) chloride. [Ca(2+)](i) was measured using fura-2. PCET-CET did not affect resting [Ca(2+)](i). PCET-CET decreased and acute EtOH withdrawal increased overall K(+)-stimulated changes in [Ca(2+)](i), but only in +NGF PCET neurons. Reducing the level of EtOH from 200 to 100 mg % decreased overall K(+)-stimulated [Ca(2+)](i) in -NGF PCET neurons. The effects of PCET-CET or PCET-CET combined with NGF on overall K(+)-stimulated changes in [Ca(2+)](i) occurred mostly in the early and middle phases of the K(+)-response. NGF reduced overall K(+)-stimulated changes in [Ca(2+)](i) in PCET neurons during EtOH withdrawal and during AET with 200 mg % EtOH and increased overall K(+)-stimulated changes in [Ca(2+)](i) during AET with 400 and 800 mg % EtOH. There was no effect of NGF on overall K(+)-stimulated changes in [Ca(2+)](i) in diet-control neurons with the exception that NGF-treatment decreased overall K(+)-stimulated changes in [Ca(2+)](i) during AET with 400 mg % EtOH. The effects of AET on overall K(+)-stimulated changes in [Ca(2+)](i) mostly occurred in +NGF PCET neurons. In conclusion, CET during development of the brain could adversely affect Ca(2+)-dependent functions such as neuronal migration, neurite outgrowth, and synaptogenesis in neurons even in the presence of neurotrophin support.

Animals↗

PubMed2002

Robots in invertebrate neuroscience.

Can we now build artificial animals? A combination of robot technology and neuroethological knowledge is enabling the development of realistic physical models of biological systems. And such systems are not only of interest to engineers. By exploring identified neural control circuits in the appropriate functional and environmental context, new insights are also provided to biologists.

Animals↗

PubMed2002

Using focus groups as a research method: a personal experience.

AIM: The personal experience and systematic process of using focus groups as a research method to assist change within an NHS Trust are described. BACKGROUND: Focus groups have recently emerged as a popular qualitative research method in health research and were used in a qualitative research study to explore, from an Enrolled Nurse perspective, what it was that prevented them coming forward for conversion to the First Level of the UKCC Nursing Register. METHOD: The author facilitated the five focus groups with Enrolled Nurse membership within the local organizational context. Data were recorded on audio-tapes and transcribed in preparation for analysis. RESULTS: The use of focus groups in health care research has key benefits for involving people in the research process and the subsequent changes that may occur as a result. The use of focus groups presented real challenges in the area of recruiting Enrolled Nurses to engage in such a process. CONCLUSIONS: Focus groups have a valuable role to play in both research and the involvement of people in organizational change and development. However, to persuade traditionally disempowered groups to engage in the process will be a challenge to the leaders of such projects.

Female↗

PubMed2002

Sex differences in ethanol-induced hypnosis and hypothermia in young Long-Evans rats.

INTRODUCTION: Females experience greater liver damage, have reduced brain size, and have greater memory deficits than do males with a similar history of alcoholism. Females have higher peak alcohol levels and faster elimination rates than males. Our goal was to study sex differences in the response of young ethanol-naïve outbred Long-Evans rats to acute ethanol exposure so that we may better understand why females are more sensitive to alcohol toxicity than males. METHODS: Females aged 49 days and males aged 43 days, weighing 153.6 and 177.5 g, respectively, were tested for their initial response to ethanol. Fasted (12 hr) females (in diestrous) and males were given an intraperitoneal injection of 3.0 g/kg of ethanol (v/v in 0.9% sterile saline). Body temperature, loss of the righting reflex (LORR), return of the righting reflex, and tail blood alcohol concentration (BAC) were monitored. RESULTS: LORR occurred at the same time in females and males. The return of the righting reflex occurred later in males than in females. BACs were the same in the males and females except at LORR, when BAC was lower in the males. Acute ethanol tolerance developed in more males than females. Females demonstrated a slower recovery from peak ethanol-induced hypothermia than males. The proportions of lean body mass, ethanol elimination, and ethanol metabolism were similar in the females and males. CONCLUSIONS: Ethanol-naïve young male and female Long-Evans rats demonstrated sex differences in their initial responses to ethanol. Males were more sensitive than females to the hypnotic effect of ethanol, whereas females were more sensitive than males to ethanol-induced hypothermia. In addition, more males than females developed acute ethanol tolerance. Investigating the mechanisms underlying these differences may help us to understand why females experience more of the adverse effects of alcohol consumption than males.

Aging↗

PubMed1998

Robots, crickets and ants: models of neural control of chemotaxis and phonotaxis.

Neural control in animals can be investigated using robot models. Two simple behaviours are focused on: pheromone trail following in ants and sound source localization in crickets. Our models address the real sensorimotor constraints and physiological underpinnings of these behaviours. Using alcohol gas sensors on a robot it is shown that a simple neural architecture can reproduce a range of trail-following behaviours that qualitatively resemble the results reported for ants. Building a more detailed auditory sensor based on the cricket ear it is shown that preference for song frequency and pattern does not require a recognition mechanism, using real cricket song as stimuli. Finally the spiking neuron models that enable us to examine exactly how these robust forms of motor control can emerge from small networks of neurons are introduced.

Journal Article↗