Cognitive Labs

A boost in the levels of serotonin, a neurotransmitter which influences anger, depression, body temperature, sexuality, sleep, and mood in human and mammal brains, has been linked to the swarming behavior of desert locusts. Scientists have found that the levels of this chemical increase 2x-3x and this causes the normally individualistic and even, anti-social insect to become hyper-social and gregarious. Accompanying the rise in serotonin is a physical color change: from brown to pink, green, and multicolored hues.

Up to 25% of the earth's surface is subject to their activity, including Africa, the Mediterranean, Western Asia, and parts of the Americas including the Southwestern U.S.



From the Abstract:

Desert locusts, Schistocerca gregaria, show extreme phenotypic plasticity, transforming between a little-seen solitarious phase and the notorious swarming gregarious phase depending on population density. An essential tipping point in the process of swarm formation is the initial switch from strong mutual aversion in solitarious locusts to coherent group formation and greater activity in gregarious locusts. We show here that serotonin, an evolutionarily conserved mediator of neuronal plasticity, is responsible for this behavioral transformation, being both necessary if behavioral gregarization is to occur and sufficient to induce it. Our data demonstrate a neurochemical mechanism linking interactions between individuals to large-scale changes in population structure and the onset of mass migration.

1 Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK.
2 Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK.
3 School of Biological Science, University of Sydney, Sydney, NSW 2006, Australia.

Labels: antsey, hoffman, oxford, serotonin, texas

A single-celled protista may revolutionize our understanding of how complex life evolved on Earth, illuminating the transition from algae, for example, to fish. With a width of up to 30 mm, or 1.2 inches, the grohia sphaerica even leaves a trail in the mud at the bottom of the sea floor.

Labels: cambrian, grohia, matz, texas

An extract of the plant oleander may offer potential as an anti-cancer treatment. Researchers at the University of Texas have been examining the properties of a derived substance and find that it inhibits the spread of a cancer growth agent and injects oxygenated free radicals into the impacted tissues, which cause cell death. Normally, presence of free radicals in the body is not positive and is associated with oxidation, aging, and cancer initiation.

However, in its natural state, all parts of the plant are very poisonous with alkanoids and glycosides and can be fatal to humans as well as grazing animals. It is ignored by omnivorous browsing deer for this reason.

Nevertheless, Pliny the Elder in Historia Naturalis observed:

The rhododendron (referring to oleander and the related desert rose) has not so much as found a Latin name among us, its other names being "rhododaphne" and "nerium." It is a marvellous fact, but the leaves of this plant are poisonous to quadrupeds; while for man, if taken in wine with rue, they are an effectual preservative against the venom of serpents. Sheep too, and goats, it is said, if they drink water in which the leaves have been steeped, will die immediately.

Labels: glycosides, oleander, pliny, texas

Gladstone Institute at UCSF and University of Texas researchers have found the APOEe4 genetic marker, known as the most significant genetic risk determinant of Alzheimer's Disease and a factor in heart disease and stroke, also may play a role in the severity of HIV in people who have the disease. Results were published in the Proceedings of the National Academy of Sciences.

A seemingly trifling sequence difference of just one amino acid has profound implications for the structure and function of the APoE4 protein. ApoE4 has an extra intra-molecular bond that results in a more compact structure, and it also is more likely to be unstable, linked to its deleterious effects. Although the apoE3 gene is the most prevalent in all human populations, with frequencies of 50%, the genetic variant that leads to production of apoE4 is also widely distributed; its prevalence is 15.% (Some sources estimate at 20% or more of all humans)

Those with two copies of APOEe4, the homogeneous zygote, had a much more rapid progressions of HIV, leading to death, than those with two copies APOEe3.

The APOEe4 protein is smaller and more compact, but more unstable - than the APOEe2 and APOEe3. The reason for the APOEe4 mutation, it is hypothesized, helped people metabolize a lean, scarce diet and avoid starvation and possibly lowered the chance of child mortality. It also may be linked to colder temperatures, or possibly to those groups with the mutation who migrated into northern latitudes - it is more prevalent in Finland as a percentage of the population than anywhere else on earth, and also amongst relatively homogeneous ethnic groups (for example, German Russians) where increased APOEe4 risk has followed such groups even after migrating to North America where it is seen in distinct family histories of Alzheimer's Disease.

Labels: apoe, apoee3, apoee4, gladstone, homogeneous, texas, ucsf, zygote