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While a great deal of studies have been devoted to explain the emerging patterns observed in schools of fish and flocks of birds, there exist many other animal collective movement phenomena where alignment does not play a role. One important example is the formation of animal territories, a form a spatial segregation relatively common in mammals. When the mechanism of territorial exclusion occurs via marks deposited on the terrain, one talks about stigmergy, a form of environment-mediated interaction often encountered in social insect societies. To study these stigmergic systems in mammals I have introduced the so-called territorial random walk model consisting of a collection of discrete random walkers that (scent) mark any lattice site they visit. As deposited marks remain active for a finite amount of time, each walker retreats upon encountering an active foreign scent. The emerging spatio-temporal dynamics of the system is analysed both at the meso and micro-scale.
At the meso-scale the scented territories can be quite rich. Short-lived marks produce rapidly morphing and highly mobile territories, while long-lived marks yield slow territories with a narrowly defined shape distribution. More importantly the full dependence in territory mobility as a function of the time for which individual marks remain active is accompanied by a liquid-hexatic-solid transition akin to the Kosterlitz-Thouless melting scenario, the first ecological model to predict such a transition.
At the micro-scale, and when population density is sufficiently large, I introduce localized walls to mimic the sharp (retreat) interaction when an animal encounters a foreign scent. A mean-field approximation then allows to represent via a Fokker-Planck formalism an animal roaming within neighbouring territorial boundaries whose movement statistics is subdiffusive and constrained by a spring whose equilibrium length makes the territory size equal to the inverse of the population density. Application of this approximate analytic model to movement data from a red fox population in Bristol, UK, is also shown.
If time allows, I will mention about an algorithmic implementation in the context of territorial searching robots.
References
[1] A. Heiblum-Robles and L. Giuggioli, Phase transitions in stigmergic territorial systems, accepted.
[2] L. Giuggioli, I. Ayre, A. Heiblum Robles and G.A. Kaminka, From ants to birds: a novel bio-inspired approach to on-line area coverage, in Groß R et al. (eds) Distributed Autonomous Robotic Systems, Springer Proceedings in Advanced Robotics, vol 6, pp. 31-43 (2018).
[3] L. Giuggioli and V.M. Kenkre, Consequences of animal interactions on their dynamics: emergence of home ranges and territoriality, Move. Ecol. 2(1), 20 (2014).
[4] L. Giuggioli, J.R. Potts, D.I. Rubenstein and S.A. Levin, Stigmergy, collective actions and animal social spacing, Proc. Natl. Acad. Sci. USA 110(42):16904-9 (2013).
[5] J.R. Potts, S. Harris and L. Giuggioli, Quantifying behavioral changes in territorial animals caused by sudden population declines, Am. Nat. 182:e73-e82 (2013).
[6] L. Giuggioli, J.R. Potts and S. Harris, Predicting oscillatory dynamics in the movement of territorial animals, J. Roy. Soc. Interface 9(72):1529-43 (2012).
[7] J.R. Potts, S. Harris and L. Giuggioli, Territorial dynamics and stable home range formation for central place foragers, PLoS ONE 7(3):e34033 (2012).
[8] L. Giuggioli, J.R. Potts and S. Harris, Brownian walkers within subdiffusing territorial boundaries, Phys. Rev. E 83:061138/1-11 (2011).
[9] L. Giuggioli, J.R. Potts and S. Harris, Animal interactions and the emergence of territoriality, PLoS Comp. Biol. 7(3):e10020

The normal function of alpha-synuclein, a protein involved in Parkinson's Disease and other synucleinopathies, remains elusive. Though recent studies suggest that alpha-synuclein is a physiological attenuator of synaptic vesicle recycling, mechanisms remain unclear. Our data show that synapsin – a cytosolic protein with established roles in synaptic vesicle mobilization and clustering – is required for alpha-synuclein function. Furthermore, we show that the two proteins interact in a reversible manner in the synapse and that in the absence of synapsins, the localization of alpha-synuclein to synapses is deficient. Our data suggest a model where alpha-synuclein and synapsin cooperate in clustering SVs and attenuating recycling.

Background: The aim of anaesthesia is to eliminate awareness and prevent memory of the various aversive stimuli of medical procedures. Yet in a portion of cases, patients can recall events that occurred during surgery resulting in risks of adverse psychological outcomes. Fear conditioning offers a robust behavioral model to study this phenomenon, while the abundant evidence implicating the amygdala-medial prefrontal cortex (mPFC) circuit in acquisition, consolidation and retrieval of these memories offers a natural hypothesis for the neural mechanisms.
Objective: We aimed to study the effect of anaesthesia on stimulus valence, acquisition and memory and to identify the correlates in the mPFC-amygdala circuit using a primate model and clinically relevant doses of anesthesia.
Materials and methods: Two non-human primates acquired aversive memories by tone-odor classical conditioning under anesthesia with different doses of ketamine, a non-competitive antagonist of NMDA and midazolam, a GABA agonist. Both agents are in wide clinical use. We simultaneously recorded single neurons in the BLA and mPFC. Analyses focused on behavioral and neural evidence suggesting maintained valence, acquisition and retention of memory.
Results: Seventy-six full sessions from two non-human primates entered analysis. We recorded 172 amygdala and 189 dACC neurons respectively. We found evidence of successful aversive conditioning under both anesthetics and in all doses. Under anesthesia, we found behavioral evidence of retention in 46% of sessions matched by a complementary response of 16.2% and 18.7% of amygdala and mPFC neurons respectively. An increased and escalating amygdala and mPFC response during acquisition predicted later retention and correlated the behavioral result. The behavioral and neural representation of aversive valence was sufficient to drive learning and affected conditioning outcome.
Conclusion: Our results suggest that under anesthesia, the perception of stimuli and implicit aversive memory formation may be maintained. We show patterns in the amygdala-mPFC circuit that precede and predict this phenomenon and that may serve future monitoring strategies of anesthetized patients. The use of a primate model and therapeutic doses of common anesthetics affecting both GABA and NMDA transmission improves the possible translation of our findings.