LMU Division of Neurobiology
Department Biology II
Großhaderner Straße 2
+49 (0)89 / 2180-74310
Fax: +49 (0)89 / 2180-74304
Our senses are not mere transducers of external information. There is increasing evidence that sensory signals, even before reaching conscious awareness, are loaded with meaning. Since the 1970s, neuroscientists have observed abundant connections between typical emotional circuits and sensory systems such as the auditory system. Additionally, several hormones like cortisol and estrogen have been found to influence audition. However, most of our knowledge about these modulatory systems suggests amygdala-hypothalamic structures or the systemic blood circulation as their origin, which makes their actions either slow or stereotypic and seemingly affecting only a limited number of natural behaviors.
So, our question is: do subcortical auditory centers possess a specialized system to detect changes in the emotional state of the animal and quickly adapt audition to the new necessities? Our group studies the stress neuropeptide Urocortin 3 (Ucn3) which is expressed in several subcortical auditory structures.
Our data indicate that Ucn3 is tonically released from auditory synapses and acts as fast as neurotransmitters to maintain proper synaptic communication. Ucn3 it can be released from presynaptic terminals in bursts of high concentrations, which then greatly perturb synaptic physiology. These results suggest that Ucn3 can act independently of other non-auditory circuits involved in stress and create highly-adaptive responses in the auditory system. Nevertheless, it is unclear what causes these release bursts, especially whether general or auditory-specific stressors are required.
The aim of this project is to utilize a general stressor (restraint stress) and a series of behaviorally-relevant auditory stimuli (e.g. alert calls, predator noises, squeaks or pup vocalizations) to study the release of Ucn3 and its effects on auditory function.
Primary Techniques: The student will be able to learn various techniques including protein extraction and quantification from brain tissue, perform behavioral testing with complex and novel auditory stimuli and conduct in vivo electrophysiological measurements (ABRs).
Experimental Model: Mouse
Specific requests: none, but prior experience in either physiology, handling of experimental animals, processing brain tissue would be welcome.