Age-associated memory impairment (AAMI) occurs in many mammalian species, including humans. In contrast to Alzheimer's disease (AD), in which circuit disruption occurs through neuron death, AAMI is due to circuit and synapse disruption in the absence of significant neuron loss and thus may be more amenable to prevention or treatment. We have investigated the effects of aging on pyramidal neurons and synapse density in layer III of area 46 in dorsolateral prefrontal cortex of young and aged, male and female rhesus monkeys (Macaca mulatta) that were tested for cognitive status through the delayed non-matching-to-sample (DNMS) and delayed response tasks. Cognitive tests revealed an age-related decrement in both acquisition and performance on DNMS. Our morphometric analyses revealed both an age-related loss of spines (33%, p Ͻ 0.05) on pyramidal cells and decreased density of axospinous synapses (32%, p Ͻ 0.01) in layer III of area 46. In addition, there was an age-related shift in the distribution of spine types reflecting a selective vulnerability of small, thin spines, thought to be particularly plastic and linked to learning. While both synapse density and the overall spine size average of an animal were predictive of number of trials required for acquisition of DNMS (i.e., learning the task), the strongest correlate of behavior was found to be the head volume of thin spines, with no correlation between behavior and mushroom spine size or density. No synaptic index correlated with memory performance once the task was learned.

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Diverse attitudes toward Malagasy prickly pear cactus demonstrate that French colonialism was not a single cohesive strategy but was marked by contradictions and struggles. Struggles among groups of colonizers included not only the control of cactus but also its appropriateness and desirability. One side of the debate attributed an aggressive and threatening agency to thorny cactus. Another side emphasized that prickly pear was a vital socioeconomic plant for pastoralists. While some French colonists implemented drastic measures against the perceived cactus threat-based more on blind hopes than scientific knowledge-others criticized interfering with the delicate symbiotic relationship between herder and cactus. Although pastoralist resistance to foreign interference took different forms during this period, avoidance was the main form.

“Famines gather history around them,” we are told, even more so, it seems, with high numbers of dead. These numbers are treated sometimes like monuments for famines, increasing over time according to utilitarian concerns. Sources for a famine on Madagascar show that though high numbers may be useful in drawing attention to a calamity, people closer to the event may not locate this history or situate their memory via numbers. Emphasizing numbers in lieu of other ways of remembering and also forgetting a calamity appear not to be very good guides to this history.The killing famine that struck southern Madagascar in 1930–31 attracted substantial written comment among the French. Everyone seemed to have an opinion about this famine, which followed the surprising and dramatic killing of the predominant species of prickly pear cactus by cochineal insects in the late 1920s. A large area, a seventh of the island (approximately a sixth of France), with a population at the time of around a half million people and perhaps two million head of cattle, was effected by the biological war on cactus. “Cactus pastoralists” were suddenly without a very resourceful plant. It had provided thick fences of protection to these herders and their cattle; its fruit and water a mainstay for people; its singed cladodes a critical source of water and sustenance for cattle.The “furnace of contamination”—the rapidly reproducing cochineal choking to death their cactus hosts—started in 1925 at the southwest provincial center of Toliara and spread to the east, north, and south at a rate of 100 kilometers per year.

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