Electrophysiological study of spinal cord thermoreceptive neurones in the rat

1 . The aim of this study was to investigate the neurophysiological basis for thermal analgesia. The speculation that part of this analgesia may be mediated via depression of nociceptor driven spinal cord tract neurones was tested.Spinal segments L6 to S1 were explored with extracellular mi'cropipette electrodes filled with a mixture of 5M sodium chloride and pontamine sky blue (2% in 0.5 M sodium acetate) in rats anaesthetised with chloralose (100 mg kg⁻¹) and urethane (700 mg kg⁻¹).3. 258 neurones were recorded from within the dorsal horn and were tested for the inhibitory effect of thermal stimulation applied to the perineal, inguinal and scrotal skin. Ten of the 258 units received only a warm inhibitory input from the skin. 57 units had an excitatory input from nociceptors, of these 24 were inhibited by warming and 2 by cooling the skin.4. Data has also teen obtained on the light microscopic anatomy of the scrotal skin and also on 73 units that had an input from thermoreceptors.5. It is suggested that thermal inhibition of units that have an input from nociceptors may provide some neurophysiological basis for thermal analgesia

Building climate resilience: Intersectionality in practice

Climate change affects women and men differently according to multiple overlapping factors such as intersectionality. Fair distribution of the benefits of climate-resilient agriculture matters given that some people, and communities, are more vulnerable to risk than others. Agricultural systems are at particular risk from climate change. As evidence shows, poor and vulnerable people disproportionately experience the worst climate impacts. Smallholder farmers, especially women and young people, are particularly vulnerable given structural inequalities that limit their access to resources, services, and agency, which ultimately limits their capacity to build resilience. If climate-smart and climate-resilient interventions do not adequately take gender differences into account, they might exacerbate gender inequalities in food systems

Antinociceptive potentiation of pethidine (demerol) by clomipramine in the late phase of formalin test in mice

Background: Pethidine, an opioid analgesic is used for pain management. Clomipramine a tricyclic antidepressant primarily used for mood management is also used to treat pain. The objective of this study was to investigate the potentiation of the analgesic effects of sub-threshold dose of pethidine by a tricyclic antidepressant, clomipramine. Methods: The antinociceptive activities of clomipramine and pethidine alone and in combination were investigated in Swiss albino mice using the formalin test. Normal saline was employed as the control. Ten animals were used in each experiment. Results: Pethidine 5mg / kg failed to cause any significant effect while the 6.25, 7.5, 8.75 and 10.0mg /kg showed highly significant antinociceptive effect (p< 0.01) compared to the controls in the late phase of formalin test. Clomipramine 0.5 mg / kg did not show any significant effect while 0.75 mg / kg caused a significant effect (p< 0.05) while 1.00 and 1.25mg /kg caused a very highly significant antinociceptive effect (p< 0.001) in the late phase of formalin test compared to the vehicle treated animals. The combination of pethidine 5mg / kg and clomipramine 0.75mg / kg caused a highly significant antinociceptive effect (P<0.01) in the late phase of formalin test. Conclusion: This study demonstrates a marked reduction in the time spent in pain behaviour produced by the combination of low dose pethidine and clomipramine in the late phase of formalin test. The findings demonstrate the potentiation of a narcotic analgesic by a tricyclic antidepressant. Pan African Medical Journal 2012 12:2

Investigation of the presence and antinociceptive function of muscarinic acetylcholine receptors in the African naked mole-rat (<i>Heterocephalus glaber</i>)

The present study investigated the cholinergic system in the African naked mole-rat (Heterocephalus glaber) with focus on the muscarinic acetylcholine receptor subtypes M(1) and M(4). The protein sequences for the subtypes m(1–5) of the naked mole-rat were compared to that of the house mouse (Mus musculus) using basic local alignment search tool (BLAST). The presence and function of M(1) and M(4) was investigated in vivo, using the formalin test with the muscarinic receptor agonists xanomeline and VU0152100. Spinal cord tissue from the naked mole-rat was used for receptor saturation binding studies with [(3)H]-N-methylscopolamine. The BLAST test revealed 95 % protein sequence homology showing the naked mole-rat to have the genetic potential to express all five muscarinic acetylcholine receptor subtypes. A significant reduction in pain behavior was demonstrated after administration of 8.4 mg/kg in the formalin test. Administration of 50 mg/kg VU0152100 resulted in a non-significant tendency towards antinociception. The antinociceptive effects were reversed by the muscarinic acetylcholine receptor antagonist atropine. Binding studies indicated presence of muscarinic acetylcholine receptors with a radioligand affinity comparable to that reported in mice. In conclusion, muscarinic acetylcholine receptor subtypes are present in the naked mole-rat and contribute to antinociception in the naked mole-rat

Variety for security: the role of households, markets and individuals in maintaining agrobiodiversity in Western Kenya

Agricultural diversity, commonly referred to as agrobiodiversity, is that part of biodiversity that is geared towards agriculture and food production. Agrobiodiversity is said to contribute much to food, nutrition and health, but there is lack of data confirming this, particularly from Eastern Africa. By assessing the role of agrobiodiversity on small scale farms, local markets and food perceptions in six villages of Mumias and Vihiga districts in Western Kenya, the study sought to answer three main research questions: (i) What is the extent of crop diversity on mixed small scale farms and how much does on-farm crop diversity contribute to farm household's food security (ii) What is the relationship between household food consumption and food available on mixed farms and in local markets, and what is the level of market integration among small scale farmers? (iii) How comparable are gender perceptions on local foods and small scale farming systems? The key findings were that: (i) crop diversity is not dependent on crop seasonality and farm sizes, and small scale farmers rely on multiple food sources to achieve household food security (ii) food consumption and availability on mixed farms and in local markets is shaped by cultural and economical reasons, and there is low integration of small scale farmers as sellers in local markets (iii) gender views on seasonality and perceptions on local foods greatly differ with regard to subsistence food crops, but not with purchased foods.</p

Variety for security: the role of households, markets and individuals in maintaining agrobiodiversity in Western Kenya

Agricultural diversity, commonly referred to as agrobiodiversity, is that part of biodiversity that is geared towards agriculture and food production. Agrobiodiversity is said to contribute much to food, nutrition and health, but there is lack of data confirming this, particularly from Eastern Africa. By assessing the role of agrobiodiversity on small scale farms, local markets and food perceptions in six villages of Mumias and Vihiga districts in Western Kenya, the study sought to answer three main research questions: (i) What is the extent of crop diversity on mixed small scale farms and how much does on-farm crop diversity contribute to farm household's food security (ii) What is the relationship between household food consumption and food available on mixed farms and in local markets, and what is the level of market integration among small scale farmers? (iii) How comparable are gender perceptions on local foods and small scale farming systems? The key findings were that: (i) crop diversity is not dependent on crop seasonality and farm sizes, and small scale farmers rely on multiple food sources to achieve household food security (ii) food consumption and availability on mixed farms and in local markets is shaped by cultural and economical reasons, and there is low integration of small scale farmers as sellers in local markets (iii) gender views on seasonality and perceptions on local foods greatly differ with regard to subsistence food crops, but not with purchased foods.</p

Housing behaviour of the naked mole rat (Heterocephalus glaber) under laboratory conditions

The naked mole rat (Heterocephalus glaber) is a rodent that has gained importance as a biomedical research model for various conditions including hypoxic brain injury, cancer and nociception. It is captured from the wild and housed under laboratory conditions during research. Much is unknown about how to optimize housing conditions for the animals in captivity. This study was designed to establish whether the animals will replicate in the laboratory their natural behaviour of having separate resting, waste disposal and eating areas. A total of 52 naked mole rats were kept in four colonies of different sizes and housed in two types of cage design. It was found that, in all four colonies, their behavior was similar to that in the wild with regards to separating their resting, eating, defecation and urination areas. Urination and defecation commonly occurred in the outer corners of the cages while resting and eating mostly occurred in the inner parts of the cages. Average daily feed consumption was 7.6 grams per naked mole rat. Weekly weight gain averaged 0.44 grams per naked mole rat. In this study, the four colonies of naked mole rats behaved similarly in their selection of resting, waste disposal and eating area. However, additional studies are needed to investigate further whether these behaviours can be affected by colony origin, colony size or cage size. The results of our study indicate that resting, eating and waste disposal behaviours need to be taken into consideration when housing naked mole rats, to optimize the comfort of these animals in captivity

Extension Support Services among Poultry Farmers, a Case of Katulani District, Kitui County

A survey was carried out to determine provision of extension support services in Katulani District, Kenya. Data was collected through observations and structured questionnaires administered to 110 poultry rearing households in rural and peri urban areas to allow for comparison. Over 75% of households practiced mixed farming with indigenous chicken being kept by all households. Extension support services were accessible to less than 50% of households with rural areas having higher accessibility. Public sector workers were the main source of extension services. About 50% of respondents requested for training on chicken rearing. The average flock size in the study area was forty chicken with chicks and pullets dominating. The cock to hen ratio was 1:2 while inbreeding rate per generation was 4.5%. The recommendation is a review of extension approaches and capacity building grassroots institutions in order to diversify extension service agents and reduce distances to source of services