The neurobiology of trichotillomania (TTM) has only recently received attention from the neuropsychiatrie community, and the number of studies in this area is limited. Nevertheless, there is tentative support for the hypothesis that serotonergic, dopaminergic, and opioid systems mediate hair-pulling symptoms, and that corticostriatal circuits also play a role. An understanding of the neurobiology of TTM may be of value not only for the treatment of this disorder, but also for other stereotypic behaviors.

Gold labels such as Nanogold® and colloidal gold are enlarged and visualized in the electron microscope or optically by the selective deposition of silver onto their surfaces. This process, known as autometallography (AMG), silver amplification or silver enhancement, is initiated by exposing the particles to a solution containing silver (I) ions and a reducing agent such as hydroquinone or npropyl gallate. Particles may be enlarged to between 30 and 100 nm in diameter, giving a distinctive black, punctate staining in the light microscope. Nanogold® labeling with silver amplification is one of the most sensitive methods available for histopathology applications such as in situ hybridization. With Catalyzed Reporter Deposition (CARD; also called Tyramide Signal Amplification, or TSA® ; NEN Life Sciences, Boston MA), it has been used to detect as few as 1-2 copies of viral DNA or RNA per cell. However, its uses are restricted by reactions of silver (I) with halides and other elements in tissues. Also, after signal development, self-nucleation and non-specific background deposition begin quickly, which can make end-point selection difficult or prevent incorporation into automated procedures.

The Poetry of Architecture, Ruskin's first collection of essays, is even more “deformed by assumption” than his autobiography admits. Architecture is defined as poetic for genteel tourists, who forget that the buildings whose beauty they admire required human labor and embody distinctions of class. Indeed, architectural poetry expresses a myth of class harmony: buildings blending into the landscape, landowners welcomed by loving tenants. Yet this vision, though apparently sanctified by nature, is threatened—by industrial landscapes, cities, and less appealing aspects of nature itself. Without poetry, architecture might seem little more than the sort of instinctive shelter building we observe in the lower animals, hence suggestive of biological kinship between human beings and “brutes.” At the heart of Ruskin's architectural dreams is a feared disappearance of all distinctions, biological as well as social—a pre-Darwinian nightmare.