Public lectures

The neurochemical control of the decision to fight or flee - lessons from crickets on aggression

Prof. Dr. Paul A Stevenson

University of Leipzig, Faculty for Biosciences, Pharmacy & Psychology Institute for Biology, Talstrasse 33, 04103 Leipzig

Aggression between individuals of the same species serves to secure limited resources, but must be exercised with constrain so that the costs of fighting do not exceed the potential benefits. Animals must thus have the capacity to decide when best to fight or flee.  This decision is thought to be based on the animal’s assessment of win chances, and is further influenced by the presence and value of resources, previous physical exertion and social experiences such as winning or losing. Conversely, early aggressive social experience, such as chronic subjugation, can have long-term consequences for future behavioural profiles, and is often associated with depression like phenomena in mice and man. The proximate mechanisms that control how diverse experiences modulate aggression, and how aggression modulates future behaviours are, however, poorly understood. While aggression is influenced by many drugs that affect neurotransmitter systems, the specific behavioural roles of natural neurochemicals is often unclear. My group works to close this knowledge gap by analysing the effects of neurochemicals on specific aspects of the highly stereotyped aggressive behaviour of crickets. We have show that physical exertion, winning and resource possession each enhance aggression via the action of octopamine, the invertebrate analogue of noradrenaline. Octopamine, thus promotes the decision to fight, and in effect represents the motivational component of aggression. The decision to flee, in contrast, is determined primarily by the nitric-oxide (NO) signalling pathway, which is activated as a result of the accumulated impact of the opponent’s aggressive actions during a fight. This also results in a period of suppressed aggressiveness in losers, known in many animals, that lasts about 3 hours in crickets. Interestingly, multiple defeats (chronic subjugation) leads to a long-term depression of aggression (> 24 h, possibly life-long). Preliminary findings indicate that this results from NO-dependant activation of the serotonergic system. In addition to suppressing aggression, chronic subjugation influences general motility, exploratory behaviour and even responsiveness towards specific mechanical stimulation. Together, our data for crickets indicate that earlier aggressive experiences, and the accompanying changes in neuromodulator systems, can establish consistent inter-individual differences in behaviour, or “personality” - a term currently in vogue for invertebrates.

Neuronal correlates of time perception in echolocating bats

Prof. Dr. Manfred Kössl

Institute for Cell Biology and Neuroscience, Goethe University, Max-von-Laue Str.13, 60438 Frankfurt/Main

Echolocating animals are a good model to study neuronal mechanisms of time perception since for orientation bats rely on a dedicated neuronal analysis of the arrival times of echoes that are reflected from different external objects.

 In the midbrain and cortex of bats there are large neuronal populations that are tuned to specific echo delays and hence target distances. We found that cortical time processing changes dynamically in dependence on the used sonar signal streams and the complexity of returning echoes. The topography of time representation sharpens considerably when using natural sonar streams and not artificial stimuli.  Cortical time-sensitive receptive fields and their chronotopic arrangement are already installed at birth, prior to full maturation of the cochlea and the emergence of echolocation behavior.




Wednesday, 2nd August 2017

from 16:00           Arrival and Registration at the youth hostel

21:00 - 22:00       city tour by night (in German)

From 22:00          Early Socializing

Thursday, 3rd August 2017

7:00 - 9:00           Breakfast at the youth hostel

10:30 - 10:45       Welcome Address

10:45 - 11:05       Talk I

11:05 - 11:25       Talk II

11:25 - 11:45       Coffee Break

11:45 - 12:05       Talk III

12:05 - 12:25       Talk IV

12:25 - 14:25       Lunch

14:25 - 14:45       Talk V

14:45 - 15:05       Talk VI

15:05 - 15:35       Coffee Break

15:35 - 16:35       Poster (Odd numbers)

16:35 - 17:35       Poster (Even numbers)

18:00 - 19:00       Plenary Talk, Paul A Stevenson

19:00 - 22:00       Get Together with Buffet and Drinks

Friday, 4th August 2017

7:00 - 9:00           Breakfast at the youth hostel

10:30 - 10:50       Talk VII

10:50 - 11:10       Talk VIII

11:10 - 11:30       Coffee Break

11:30 - 11:50       Talk IX

11:50 - 12:10       Talk X

12:10 - 14:10       Lunch

14:10 - 15:10       Botanical garden / Free Time / Group Photograph

15:10 - 15:40       Coffee Break

15:40 - 16:40       Poster ODD

16:40 - 17:40       Poster EVEN

18:00 - 19:00       Plenary Talk, Manfred Kössl

19:00 - 19:30       Prizes and announcements

19:30 - 22:00       Farewell barbecue

Saturday, 5th August 2017

Until 9:00              Departure


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