Our survival and well-being as individuals depends critically on the ability of our nervous system to detect threats and opportunities, and initiate appropriate behavioural, hormonal and physiological responses. These mechanisms allow us to defend ourselves against a predator and establish hierarchies, make sure that we have enough fuel through feeding and energy utilization, and court, mate and raise offspring. The behavioural sequences also require that our brains can adapt sleep and alertness to intrinsic needs and conditions on the ground. In our work, we ask how the neural circuits in the hypothalamus and cerebral cortex that underlie such phenomena are constructed and connected. We approach these questions with a combination of electrophysiological recording techniques, behavioural paradigms and neuroanatomical and molecular approaches. Our work focuses in particular on:
- Hypothalamic dopamine neurons. This includes the neuroendocrine tuberoinfundibular dopamine (TIDA) neurons that control pituitary hormone release and regulate lactation and maternal behavior. In TIDA cells, we have identified a robust network oscillation. We are investigating the mechanisms and functional relevance of this powerful circuit rhythm..
- In the cerebral cortex, we study the key neurons and transmitter actions that underlie the switch between network states associated with sleep and wakefulness. This work that has led us to focus on the so-called “persistent subplate neurons” in layer 6b and interspersed in the cortical white matter.
- The nucleobindins (NUCBs), a family of Ca2+- and DNA-binding proteins that we have identified in the brain and pancreatic islets of Langerhans. Where are they distributed and what is their role in the signalling of the body’s two major communication systems, the neural and endocrine?
This work has implications for e.g. the understanding of normal fertility, aggression, sleep disorders and metabolism and diabetes.
a) Reconstructed recorded TIDA neuron (green) stained by immunofluorescence for tyrosine hydroxylase (red). b) Whole-cell current clamp recording from a spontaneously oscillating TIDA neuron. (Hellysaz, Stagourakis, Lyons, Briffaud & Broberger, unpubl.)
Dopamine Autoreceptor Regulation of a Hypothalamic Dopaminergic Network.
Cell Rep 2016 Apr;15(4):735-747
Arash Hellysaz - PhD student
Carolina Thörn Pérez - Postdoc
Christian Broberger - Senior researcher (appointed by VR)
Olof Lagerlöf - Research intern
Paul Williams - PhD student
Rachida Ammari - Postdoc
Stefanos Stagkourakis - PhD student