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Coordination of neuronal activity between two brain areas, the amygdala and the hippocampus, as well as precisely-timed integration of sensory inputs in the amygdala, are critical for emotional memories. Amygdala neurons that release the inhibitory neurotransmitter GABA (GABAergic cells) are expected to play key roles in these events, but their precise identity and function are not known.

New research by the Capogna and Magill groups in the Unit sheds new light on the functional roles of various GABAergic cell types of amygdala in orchestrating network oscillations and responses to intense sensory stimulation. Bienvenu et al. discovered that distinct types of GABAergic cell fulfil specialised and complementary roles in regulating network activities of amygdala. They identified and fully characterized for the first time the activity of four types of GABAergic cells in the rat amygdala: axo-axonic cells, parvalbumin-expressing basket cells, calbindin-expressing dendrite targeting cells, and “AStria (amygdala-striatum transitional area)-projecting” cells.

• First comprehensive definition of GABAergic cell types in the amygdala
• Identification of the neuronal connectivity of each cell type
• GABAergic cell-type-specific coding of hippocampal rhythmic activity and sensory stimuli

Movement difficulties in people with Parkinson’s disease arise because of the disturbed electrical activity of nerve cells in the brain.  Excessive rhythmic activities called ‘beta oscillations’ are one key disturbance.  Research carried out at the Unit has given new insights into why and how these beta oscillations might emerge throughout the Parkinsonian brain.  By matching the electrical activity of individual nerve cells to their connections, members of the Magill group have discovered that two different types of cell in a brain area called the external globus pallidus (GPe) could perform a division of labour to control many other areas important for movement.  In their recently published paper, the team also reveal a novel type of GPe cell that provides massive and specific connections to the striatum, a brain area that is of central importance in Parkinson’s.  Because these remarkable GPe cells are positioned to cast wide nets of influence over their targets, they were termed “arkypallidal neurons” (from ancient Greek αρκυς [arkys] for ‘hunter’s net’).  Dr. Magill commented, “Exposing the striking diversity of GPe cells is a game changer for the field.  The challenge ahead now is to explain the building blocks and necessity of this diversity”.

This research was highlighted in 'Neuroanatomy: Out with the old (model)' by Leonie Welberg, Nature Reviews Neuroscience 13, 518-519 (August 2012).

In a recent publication an interesting art-science collaboration is described. Do You Mind? paired early career neuroscientists with artists to develop cross-disciplinary dialogue, and innovative artworks. The project was initiated and co-curated by Bolam Group member Dr Megan Dowie before she joined the ANU. 

This photo is the feature image for the PLoS Biology June 2012 issue. When artist Tom Henry visited Renee Gordon in her neurodegeneration research lab she showed him cultured astrocytes using a fluorescent microscope (shown in green, nuclei in blue). Tom commented that her images "evoked everything from star-like galaxies to seaweed forests," and in response produced prints by pressing paint between surfaces to create semi-symmetric shapes, referencing brain hemispheres and regeneration of cells (image credit: Renee Gordon). 

Megan has recently set up another art-science collaboration, between the Basal Ganglia researchers at the ANU and artists from Central Saint Martins in London. What began as a lab visit will culminate in an exhibition in October. Details about A Nervous Encounter will follow. 

The Unit held its Summer Science Day on Friday 29 June 2012. The event this year was held at the TS Eliot Theatre, Merton College, founded in 1264, is one of the oldest colleges in Oxford and, with its medieval buildings, one of the most beautiful.

Presentations featured ongoing projects and future proposals.