BMe Research Grant
The Neuronal Network and Behaviour Research group of the MTA TTK was founded in 2015 by Dr. Ferenc Mátyás. The group’s main focus is the cell-specific investigation of different brain processes, such as sleep and emotional behaviour. In our experiments we combine viral-based neuroanatomical, multisite in vivo electrophysiological and behavioural approaches in special transgenic animal models (mouse).
It was suggested several decades ago that the medial part of the so called thalamus (an ancient structure in the middle of the brain) is essential in the control of arousal-related neural processes2. The first experiments investigating this theory demonstrated that electric stimulation of the medial thalamus led to desynchronization of cortical activity, which is the electrophysiological sign of wakefulness3. In accordance with this, deep brain stimulation of this brain region improved motor and cognitive skill in some comatose patients4 (Figure 1).
Figure 1. Deep brain stimulation of the MT of a comatose patient. The stimulators can be seen in the middle of the image. The patient’s motor and cognitive skill temporarily improved following the stimulation. Source: N. D. Schiff et al. 2007
However, electric stimulation is a non-specific experimental approach. It means that using this method, one cannot be sure about the source of the behavioural change (i.e. waking up), because the electricity provided by the stimulation probably reaches several cell-types, or even completely different brain regions (Figure 2). This can be the reason why the efficacy of these treatments is relatively low, and thus, these are still not common in clinical use. Similar pitfalls are also present in other widely used neuroscientific methods, such as lesions and pharmacological activation/inactivation. Using these techniques does not reveal either which neurons of the thalamus are responsible for this arousal-promoting feature. Therefore, our research group combined several cutting edge experimental tools, such as special genetically modified experimental animal models and altered virus strains in order to reveal the exact source of this thalamic arousal regulation.
1. R. M. Yerkes, J. D. Dodson, The relation of strength of stimulus to rapidity of habit-formation. J. Comp. Neurol. Psychol. 18, 459–482 (1908).
2. Y. D. Van der Werf, M. P. Witter, H. J. Groenewegen, The intralaminar and midline nuclei of the thalamus. Anatomical and functional evidence for participation in processes of arousal and awareness. Brain Res. Brain Res. Rev. 39, 107–40 (2002).
3. R. Morison, E. Dempsey, A study of thalamo-cortical relations. Am. J.Physiol. 135, 281–292 (1941).
4. N. D. Schiff et al., Behavioural improvements with thalamic stimulation after severe traumatic brain injury. Nature. 448, 600–3 (2007).
5. R. P. Vertes, W. B. Hoover, Projections of the paraventricular and paratenial nuclei of the dorsal midline thalamus in the rat. J. Comp. Neurol. 508, 212–37 (2008).
6. W. B. Hoover, R. P. Vertes, Collateral projections from nucleus reuniens of thalamus to hippocampus and medial prefrontal cortex in the rat: a single and double retrograde fluorescent labeling study. Brain Struct. Funct. 217, 191–209 (2012).