The behavioral immune system is designed to avoid infected individuals,not outgroups

What is the adapted structure of the behavioral immune system? By definition, the behavioral immune system motivates pathogen avoidance. One prominent suggestion is that the behavioral immune system also contains an additional component that generates motivation to avoid individuals from unfamiliar outgroups. The evolvability of this component has recently been questioned, however, and it has been noted that all supportive evidence stems from WEIRD samples. In this paper, we conducted between-subject experiments in large samples of adult residents of the USA (N = 1615) and India (N = 1969). In the experiment, we measured comfort with physical contact with a depicted individual. The individual was either from an ethnic ingroup or outgroup and either showed a pathogen cue or not. Results were inconsistent with the view that the behavioral immune system motivates the avoidance of individuals from unfamiliar outgroups. Instead, the results strongly supported that the system simply motivates the avoidance of any infected individual regardless of their group membership.     

Reconstruction of neocortex: Organelles,compartments, cells,circuits, and activity

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The photoreceptor system in the retinae of two dogfishes, Scyliorhinus canicula and Galeus melastomus: possible relationship with depth distribution and predatory lifestyle

The small spotted dogfish Scyliorhinus canicula and the blackmouth dogfish Galeus melastomus, whose depth distributions overlap in the upper part of the slope (c. 500 m depth), where they have access to the same prey community, have well‐developed eyes and a pure‐rod retina with a single layer of photoreceptors. Interspecific differences in rod outer segment length (L_ROS) within retinal regions were found. In the periphery and the retinal centre G. melastomus showed a L_ROS 24 and 30% longer, respectively, than S. canicula and, therefore, a potential for increased sensitivity. In both species longer L_ROS were always found in correspondence with the retinal centre where the ganglion cell topography formed a horizontal meridian that allowed for better discrimination of the horizon in the visual field. In this area L_ROS reached 53·4±4·1μm in S. canicula and 77·1±10·5μm in G. melastomus against 46·3±4·2μm and 61·1±10·1μm in the retinal periphery. No significant differences were recorded in L_ROS and rod density during growth. In both species, a rapid increase of theoretical visual acuity was found to be related to an increase in fish L_T and lens size. Visual acuity ranged between 1·7 and 3 cycles degree^‐1 in S. canicula and 2·4 and 4·2 in G. melastomus. The G. melastomus rod visual pigment showed the characteristic spectral adaptation to vision in deep‐water (λ_max of 481 nm), but was also well placed to detect the bioluminescence of some of its main prey species. In S. canicula the visual pigment absorption (λ_max of 496 nm) was more typical of shallow water living fishes. The opsin sequences of the two visual pigments are discussed and key amino acid sites were identified where sequence changes could be responsible for the spectral absorption differences between the two species. The possible relationship between L^ROS, visual acuity, visual pigment absorption, depth distribution and feeding behaviour are discussed.     

PD 142676 (CI 1002), a novel anticholinesterase and muscarinic antagonist

Inhibition of brain acetylcholinesterase (AChE) can provide relief from the cognitive loss associated with Alzheimer's disease (AD). However, unwanted peripheral side effects often limit the usefulness of the available anticholinesterases. Recently, we identified a dihydroquinazoline compound, PD 142676 (CI 1002) that is a potent anticholinesterase and a functional muscarinic antagonist at higher concentrations. Peripherally, PD 14276, unlike other anticholinesterases, inhibits gastrointestinal motility in rats, an effect consistent with its muscarinic antagonist properties. Centrally, the compound acts as a cholinomimetic. In rats, PD 142676, decreases core body temperature. It also increases neocortical arousal, as measured by quantitative electroencephalography, and cortical acetylcholine levels, measured by in vivo microdialysis. The compound improves the performance of C57/B10j mice in a water maze task and of aged rhesus monkeys in a delayed match-to-sample task involving short-term memory. The combined effect of AChE inhibition and muscarinic antagonism distinguishes PD 142676 from other anticholinesterases and may be useful in treating the cognitive dysfunction of AD and produce fewer peripheral side effects.     

Octopamine Release from Centrifugal Fibers of the Limulus Peripheral Visual System

Abstract: Octopamine, a biogenic amine, is synthesized and stored within centrifugal (efferent) fibers that project from the brain to the lateral and ventral eyes of the horseshoe crab, Limulus polyphemus . The experiments described here show that depolarization of Limulus lateral and ventral eyes, produced by elevating the concentration of extracellular K⁺, causes the selective release of newly synthesized octopamine from centrifugal fibers in a manner that requires the influx of extracellular Ca²⁺. Conjugates of octopamine and tyramine that are also stored within centrifugal fibers are not released in response to K⁺-induced depolarization. These findings add further support to the hypothesis that octopamine is a neurotransmitter synthesized by and released from centrifugal fibers in Limulus eyes. This amine may be responsible for many of the alterations in lateral eye structure and function that are mediated by centrifugal inner-vation.