Researchers detect “switch-matrix” brain functions that guide behaviour

February 17, 2014 // By Graham Prophet
Research scientists working in the field of neurobiology, and attempting to develop a more detailed understanding of how our (and other creatures’) brains work at a biological/electrical level, have reported findings that the habenula, a specific part in our brain consisting of neural circuits, acts as a gate for sensory information, thus regulating behaviour in response to external stimuli.

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).