Selective gray matter staining of human brain slices: optimized use of cadaver materials

We report a novel staining technique for human brain slices that distinguishes clearly gray from white matter. Previously described techniques using either Prussian blue (Berlin blue) or phthalocyanine dyes usually have included a hot phenol pretreatment to prevent white matter staining. The technique we describe here does not require hot phenol pretreatment and allows the use of brains stored for postmortem periods of one to two years prior to staining. Our technique involves staining with copper(II) phthalocyanine-tetrasulfonic acid tetrasodium salt 1% in water for 2 h followed by acetic acid treatment; this produces excellent blue staining of gray matter with little white matter staining. The stained brain slices are excellent for teaching human brain anatomy and/or pathology, or for research purposes.     

Human and nonhuman primate brains: Are they allometrically scaled versions of the same design?

Allometric analyses of brain structure sizes across the primate order demonstrate that human, ape, and other anthropoid brains are not simply allometrically scaled versions of the same generalized design. Both human and ape brains exhibit specializations with respect to other anthropoid brains. Ape specializations include elaboration of the cerebellum (all apes) and frontal lobes (great apes only), and probably connectivity between them. Human brain specializations include an overall larger proportion of neocortex, with disproportionate enlargement of prefrontal and temporal association cortices; an apparent increase in cerebellar connections with cerebral cortical association areas involved in cognition; and a probable augmentation of intracortical connectivity in prefrontal cortex.     

Ontogeny,maturation and plasticity of the olfactory system in the workerbee

The ontogeny and maturation of the olfactory system in the workerbee have been studied using a combination of neurophysiological (first order neurones) and neuroanatomical techniques (second order neurones). EAG recordings show that normal maturation of the olfactory response takes place during the first 4 days following emergence, and is closely related to the sensory environment during the same period. The synaptic organization of first order and second order neurones of the antennal afferent pathway (analyzed at the level of the glomeruli in the deutocerebrum) is essentially complete three days before emergence. These results are discussed in relation to a possible role of the sensory environment during the period from 3 days before until 8 days after emergence.     

Two visual systems in one eyestalk: The unusual optic lobe metamorphosis in the stomatopod Alima pacifica

The compound eyes of adult stomatopod crustaceans have two to six ommatidial rows at the equator, called the midband, that are often specialized for color and polarization vision. Beneath the retina, this midband specialization is represented as enlarged optic lobe lamina cartridges and a hernia‐like expansion in the medulla. We studied how the optic lobe transforms from the larvae, which possess typical crustacean larval compound eyes without a specialized midband, through metamorphosis into the adults with the midband in a two midband‐row species Alima pacifica. Using histological staining, immunolabeling, and 3D reconstruction, we show that the last‐stage stomatopod larvae possess double‐retina eyes, in which the developing adult visual system forms adjacent to, but separate from, the larval visual system. Beneath the two retinas, the optic lobe also contains two sets of optic neuropils, comprising of a larval lamina, medulla, and lobula, as well as an adult lamina, medulla, and lobula. The larval eye and all larval optic neuropils degenerate and disappear approximately a week after metamorphosis. In stomatopods, the unique adult visual system and all optic neuropils develop alongside the larval system in the eyestalk of last‐stage larvae, where two visual systems and two independent visual processing pathways coexist. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 3–14, 2018     

Brain morphology of the threespine stickleback (Gasterosteus aculeatus) varies inconsistently with respect to habitat complexity: A test of the Clever Foraging Hypothesis

The Clever Foraging Hypothesis asserts that organisms living in a more spatially complex environment will have a greater neurological capacity for cognitive processes related to spatial memory, navigation, and foraging. Because the telencephalon is often associated with spatial memory and navigation tasks, this hypothesis predicts a positive association between telencephalon size and environmental complexity. The association between habitat complexity and brain size has been supported by comparative studies across multiple species but has not been widely studied at the within‐species level. We tested for covariation between environmental complexity and neuroanatomy of threespine stickleback (Gasterosteus aculeatus ) collected from 15 pairs of lakes and their parapatric streams on Vancouver Island. In most pairs, neuroanatomy differed between the adjoining lake and stream populations. However, the magnitude and direction of this difference were inconsistent between watersheds and did not covary strongly with measures of within‐site environmental heterogeneity. Overall, we find weak support for the Clever Foraging Hypothesis in our study.     

Complete Connectomic Reconstruction of Olfactory Projection Neurons in the Fly Brain

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