Researchers detect “switch-matrix” brain functions that guide behaviour
The work aims to uncover how our brains combine information from the external world (sensory stimulation) with information on our internal state such as hunger, fear or stress.
NERF is a combined research effort between Belgian nanoelectronics research centre imec, VIB, and KU Leuven. Emre Yaksi of NERF comments, “Our brain has high levels of spontaneous activity, even in the absence of sensory stimulation. We think that this spontaneous neural activity in combination with sensory stimulation results in a particular internal state of the habenula. By this functional organization the habenula acts as a kind of switch board, selecting certain sensory information and sending it to the downstream brainstem areas. Thus the habenula regulates our behaviour. It will be interesting to test whether experience or learning can alter the functional organisation of these circuits.”
Neuroscientists continue to investigate the brain’s processes. The activity of single neurons and the functioning of ‘one-to-one’ interactions have been examined in detail, but information processing at the level of neural circuits is less well-understood. Emre Yaksi and his NERF colleagues integrate neurobiology and nano-scale engineering to study brain function at multiple levels of detail. This multidisciplinary approach enables the researchers to look beyond the brain cells, and it provides them with great tools to study neural circuits and their link with behaviour.
A model that provides a – relatively – simple brain structure to attempt to gain a wider understanding of brain function is the zebrafish; in its developmental stage the body of the zebrafish is transparent and optical stimulus and observation of neural tissue is possible. Researchers focused on the dorsal habenula (dHb) in zebrafish. The dHb is an equivalent of the habenula in mammals and relays information from the sensory areas to the brain region that regulates animal behaviour under stress conditions. In zebrafish, the dHb receives input from cells of the olfactory bulbthus odors can trigger distinct behaviours (e.g. feeding, courtship, alarm).
Spontaneous activity is highly organized
The ongoing spontaneous activity in neurons was thought to be associated with several neurological phenomenons, such as sleep, or the learning and sensory process. The researchers observed that dHb is highly active even in the absence of any sensory stimulation. Moreover they showed that the spontaneous activity of dHb is not random but highly structured in the spatial clusters of neurons. Later the team showed that this spontaneous activity is very prominent during sensory stimulation and governs the odor responses in the dHb. The scientists their conclusion is that dHb acts like a switch board for the sensory information and is controlled by spontaneous activity.
The bodies collaborating in this work are;
VIB: a non-profit research institute in life sciences. About 1,300 scientists conduct strategic basic research on the molecular mechanisms that are responsible for the functioning of the human body, plants, and microorganisms. Through a close partnership with four Flemish universities − UGent, KU Leuven, University of Antwerp, and Vrije Universiteit Brussel − and a solid funding program, VIB unites the forces of 83 research groups in a single institute. The goal of the research is to extend the boundaries of our knowledge of life. More information: www.vib.be
NERF – Neuro-Electronics Research Flanders (NERF) is a not-for-profit academic research initiative with the ultimate goal of forming a thorough understanding of brain function at multiple levels of detail ranging from cells and circuits to behaviour. New insights into the operation of brain circuits are empowered by the development of novel technologies that integrate neurobiology and nano-scale engineering. NERF is a joint initiative of imec, KU Leuven and VIB, supported by the Flemish Government. www.nerf.be
imec – performs world-leading research in nanoelectronics. Imec leverages its scientific knowledge with the innovative power of its global partnerships in ICT, healthcare and energy. Imec delivers industry-relevant technology solutions. www.imec.be
KU Leuven (University of Leuven) is a leading European research university dedicated to excellent research, education and service to society. www.kuleuven.be/english/
[zebrafish image; wikipedia]