NHBRU and IHR in Nottingham, PhD in Neuroscience

Columnar organisation of the speech area of human cerebral cortex

with Dr Mark Wallace, Prof. Alan Palmer and Prof. Deb Hall
markw@ihr.mrc.ac.uk, alan@ihr.mrc.ac.uk, deb.hall@nottingham.ac.uk

Vocal communication is practiced by many different types of animals, but speech is a uniquely human skill. Despite over a century of research, it remains unclear whether the area of the brain that subserves speech perception in humans (“Wernicke’s area”) is special in terms of its microscopic structure or function. One striking feature of Wernicke’s area is the neatly geometric way in which bundles of myelinated axons are arranged. This project will make quantitative measurements of the size and distribution of these axon bundles using both microanatomical analysis and high-resolution magnetic resonance (MR) imaging of post-mortem brains.

Many regions of neocortex are organised into cylindrical “micro-columns” of cells. Each micro-column contains around 100 neurons and is thought to subserve a unitary functional role (Peters and Sethares, 1997). In the primate auditory cortex, this micro-columnar structure is reflected in a strikingly regular array of tightly grouped bundles of myelinated axons (Wallace and He, 2011). This regular geometric structure of axon bundles is particularly prominent in some parts of the human auditory cortex, suggesting that it may be important for speech processing. This project will investigate this hypothesis by measuring the geometric structure of axon bundles within the different subdivisions of the human auditory speech area (Wernicke’s area). The project will involve systematic microanatomical analysis, as well as high-resolution MR imaging at ultrahigh field strengths (7 Tesla).

Applications are welcome from graduates with a first- or upper second-class degree in a relevant area of the life sciences, such as anatomy or neuroscience. You will receive extensive training in histological sectioning and staining and in high-resolution structural MR imaging.

Peters A and Sethares C (1997) The organization of double bouquet cells in monkey striate cortex. Journal of Neurocytology 26:779-797.

Wallace MN & He J (2011). Intrinsic Connections of the Auditory Cortex. In: The Auditory Cortex, Winer JA & Schreiner CE (Eds), Springer, New York, pp. 133-145.