Are horses capable of mirror self-recognition? A pilot study

Mirror Self-Recognition (MSR) unveils complex cognitive, social and emotional skills and it has been found only in humans and few other species, such as great apes, dolphins, elephants and magpies. In this pilot study, we tested if horses show the capacity of MSR. Four subjects living socially under naturalistic conditions were selected for the experiment. We adopted the classical mark test, which consists in placing a coloured mark on an out-of-view body part, visible only through mirror inspection. If the animal considers the image as its own, it will use its reflection to detect the mark and will try to explore it. We enhanced the classical paradigm by introducing a double-check control. Only in the presence of the reflecting surface, animals performed tactile and olfactory exploration of the mirror and looked behind it. These behaviors suggest that subjects were trying to associate multiple sensory cues (visual, tactile and olfactory) to the image in the mirror. The lack of correspondence between the collected stimuli in front of the mirror and the response to the colored mark lead us to affirm that horses are able to perceive that the reflected image is incongruent when compared with the memorized information of a real horse. However, without replication of data, the self-directed behavior towards the colored marks showed by our horses cannot be sufficient per se to affirm that horses are capable of self-recognition

ProNGF Is a Cell-Type-Specific Mitogen for Adult Hippocampal and for Induced Neural Stem Cells.

Abstract The role of proNGF, the precursor of nerve growth factor (NGF), in the biology of adult neural stem cells (aNSCs) is still unclear. Here, we analyzed adult hippocampal neurogenesis in AD11 transgenic mice, in which the constitutive expression of anti-NGF antibody leads to an imbalance of proNGF over mature NGF. We found increased proliferation of progenitors but a reduced neurogenesis in the AD11 dentate gyrus (DG)-hippocampus (HP). Also in vitro, AD11 hippocampal neural stem cells (NSCs) proliferated more, but were unable to differentiate into morphologically mature neurons. By treating wild-type hippocampal progenitors with the uncleavable form of proNGF (proNGF-KR), we demonstrated that proNGF acts as mitogen on aNSCs at low concentration. The mitogenic effect of proNGF was specifically addressed to the radial glia-like (RGL) stem cells through the induction of cyclin D1 expression. These cells express high levels of p75NTR, as demonstrated by immunofluorescence analyses performed ex vivo on RGL cells isolated from freshly dissociated HP-DG or selected in vitro from NSCs by leukemia inhibitory factor. Clonogenic assay performed in the absence of mitogens showed that RGLs respond to proNGF-KR by reactivating their proliferation and thus leading to neurospheres formation. The mitogenic effect of proNGF was further exploited in the expansion of mouse-induced neural stem cells (iNSCs). Chronic exposure of iNSCs to proNGF-KR increased their proliferation. Altogether, we demonstrated that proNGF acts as mitogen on hippocampal and iNSCs. Stem Cells 2019;37:1223–123

Exploiting natural polysaccharides to enhance in vitro bio-constructs of primary neurons and progenitor cells

Current strategies in Central Nervous System (CNS) repair focus on the engineering of artificial scaffolds for guiding and promoting neuronal tissue regrowth. Ideally, one should combine such synthetic structures with stem cell therapies, encapsulating progenitor cells and instructing their differentiation and growth. We used developments in the design, synthesis, and characterization of polysaccharide-based bioactive polymeric materials for testing the ideal composite supporting neuronal network growth, synapse formation and stem cell differentiation into neurons and motor neurons. Moreover, we investigated the feasibility of combining these approaches with engineered mesenchymal stem cells able to release neurotrophic factors. We show here that composite bio-constructs made of Chitlac, a Chitosan derivative, favor hippocampal neuronal growth, synapse formation and the differentiation of progenitors into the proper neuronal lineage, that can be improved by local and continuous delivery of neurotrophins. Statement of Significance In our work, we characterized polysaccharide-based bioactive platforms as biocompatible materials for nerve tissue engineering. We show that Chitlac-thick substrates are able to promote neuronal growth, differentiation, maturation and formation of active synapses. These observations support this new material as a promising candidate for the development of complex bio-constructs promoting central nervous system regeneration. Our novel findings sustain the exploitation of polysaccharide-based scaffolds able to favour neuronal network reconstruction. Our study shows that Chitlac-thick may be an ideal candidate for the design of biomaterial scaffolds enriched with stem cell therapies as an innovative approach for central nervous system repair

Plasticità della comunicazione facciale in contesto ludico e grado di tolleranza sociale: un confronto tra Macaca tonkeana e Macaca fuscata

Il gioco riveste un ruolo di primo piano nella gestione delle relazioni tra gli individui di una società. Questo comportamento viene considerato come volontario, intenzionale e gratificante. Al di là delle sue molte definizioni, il gioco è un comportamento multifunzionale con un ruolo specifico non solo nello sviluppo delle capacità individuali (imparare a gestire diverse situazioni a seconda del sesso o dell’età del partner), ma anche e soprattutto nella comunicazione inter-individuale: infatti esso può essere considerato un “ponte sociale”, una palestra per conoscere sé stessi e gli altri. Lo scambio di informazioni durante le sessioni ludiche permette lo sviluppo della competenza sociale, promuove i legami tra i soggetti ed aumenta i livelli di tolleranza coadiuvando la gestione dei conflitti. Dunque il gioco sociale rappresenta un buon indicatore della qualità dei rapporti inter-individuali e la variabilità dello stesso può riflettere importanti parametri del sistema sociale in cui si esprime, come ad esempio il grado di tolleranza. Basandosi su questi presupposti, è lecito pensare che specie con differenti sistemi sociali presentino differenze nell’attività ludica e nei suoi moduli comunicativi. Nonostante le caratteristiche generali che accomunano le diverse specie, i macachi mostrano un’elevata variabilità interspecifica a livello comportamentale che si riflette in differenti stili di socialità, rappresentando quindi un buon modello per lo studio dei diversi tipi di gestione del gioco in base alla natura delle relazioni. Il mio lavoro di tesi si prefigge di indagare la comunicazione tra gli individui, utilizzando il comportamento di gioco come substrato e si pone lo scopo di confrontare l’uso dei segnali di gioco in individui appartenenti a Macaca fuscata e Macaca tonkeana, due specie affini che però hanno una struttura sociale differente, rispettivamente ad organizzazione despotica ed egalitaria, secondo la classificazione di Thierry. Nelle sessioni ludiche l’individuo si interfaccia con l’altro utilizzando le espressioni facciali. La capacità di esibire la giusta espressione nel giusto contesto cresce con l’esperienza del gioco sociale, durante il quale poter prevedere le intenzioni del compagno diventa fondamentale, così come evitare di essere fraintesi. Nei primati la tipica espressione facciale è il relaxed open-mouth display che può presentarsi in due differenti configurazioni: la play face (la bocca è aperta con l’arcata inferiore esposta) e la full play face (le arcate superiore e inferiore sono entrambe esposte). Nel presente lavoro si è anche tenuto conto delle espressioni "non specifiche", utilizzate cioè in contesti giocosi così come in altri.In questo studio non si è solo indagato il ruolo dei segnali di gioco a livello individuale, ma soprattutto nel processo imitativo che scatta tra due giocatori. Nell'uomo esistono due risposte possibili ad un'espressione facciale, una "risata" automatica (entro 1 secondo) e una non-automatica (entro 5 secondi) e così accade anche nei primati non umani. Nello specifico in queste due specie di Macaca è stata indagata la presenza del fenomeno del Rapid Facial Mimicry, cioè il fenomeno per cui all'espressione facciale dell'emettitore, il ricevente risponde con la stessa espressione in modo automatico, entro un secondo.Se è vero che il substrato sociale di un individuo influisce sulla gestione dei rapporti e dei comportamenti,come appunto il gioco, ci aspettiamo di trovare differenti risultati in M. tonkeana e M. fuscata, dovuti al diverso stile di organizzazione sociale. I dati sono stati raccolti in colonie in cattività su un gruppo di Macaca fuscata (Olomuc Zoo, Rep. Ceca) e un gruppo di Macaca tonkeana (Parc Zoologique di Thoiry, Francia).Tutte le sessioni di gioco sono state video-registrate. E’ seguita poi una video analisi tramite il software Kinovea v.0.7.10 (1 fotogramma/4 centesimi di secondo) e ogni espressione facciale (emettitore, ricevente, durata, eventuale risposta) è stata inserita in un foglio di lavoro insieme a tutti i pattern giocosi osservati (seguendo un etogramma prestabilito). Al momento sono state analizzate 100 sessioni di gioco. Le analisi, per ora condotte solo su M. tonkeana, hanno voluto indagare l'ipotesi che le espressioni facciali non coinvolgano solo la sfera emotiva, ma anche intenzionale. I risultati finora ottenuti hanno mostrato che effettivamente i segnali di gioco servono a gestire al meglio le sessioni e che le coppie di individui che giocano più insieme sono anche quelle che "ridono" di più, in termini di durata dell'espressione. Inoltre maggiore è il grado di attenzione del ricevente, maggiore sarà il numero di espressioni eseguite dall'emettitore: ovvero, solo quando quest'ultimo è consapevole di essere guardato palesa le sue intenzioni attraverso i segnali visivi. Per quanto riguarda invece la sfera emotiva, è stata osservata e confermata la presenza del processo imitativo Rapid Facial Mimicry in questa specie, quando il contatto visivo tra i giocatori è diretto.Il lavoro proseguirà indagando gli stessi fenomeni nei despotici Macaca fuscata e di continuare a condurre altre analisi in parallelo tra le due specie

Mimic Me While Playing! Social Tolerance and Rapid Facial Mimicry in Macaques (Macaca tonkeana and Macaca fuscata)

Social play and tolerance are positively correlated and playful signals are more freely expressed in egalitarian than in despotic species. Macaque species are organized along a continuum from intolerant to tolerant social systems and, for this reason, they are good models to test some hypotheses about the possible linkage between communication and tolerance. We compared facial playful communication in 2 macaque species at opposite ends of the continuum: despotic Japanese macaques, Macaca fuscata, and tolerant Tonkean macaques, Macaca tonkeana. We predicted that tolerance has favored larger facial display repertoires and playful cooperative tendency. Moreover, we evaluated if tolerance could also reflect in the selection for emotional sharing expressed through rapid facial mimicry (RFM). RFM is an automatic, unconscious, and fast (1 s) motor mirror response which favors emotional communication between subjects. Although M. fuscata and M. tonkeana performed play faces (PF) at comparable levels, only Tonkean macaques showed the phenomenon of RFM. The playful sessions characterized by RFM lasted longer than those characterized by the presence of playful signals perceived by a playmate but not followed by mimicry. Interestingly, the duration of playful sessions in Tonkean macaques overcame that of the sessions in Japanese macaques. It is likely that RFM improves communicative exchanges between the playmates and, at the same time, promotes behavioral coordination and cooperation in the sequence of actions. The tolerant nature of Tonkean macaques, also expressed in play, can foster RFM which, at the same time, positively enhances the propensity to cooperate in a sort of positive feedback

Integrating Tinbergen's inquiries: Mimicry and play in humans and other social mammals

Visual signals convey emotions and intentions between individuals. Darwin underlined that human facial expressions represent a shared heritage between our species and many other social mammals. Social play is a fertile field to examine the role and the potential communicative function of facial expressions. The relaxed open-mouth (or play face) is a context-specific playful expression, which is widespread in human and non-human mammals. Here, we focus on playful communication by applying Tinbergen’s four areas of inquiry: proximate causation, ontogeny, function, and evolution. First of all we explore mimicry by focusing on its neural substrates and factors of modulation within playful and non-playful context (proximate causation). Play face is one of the earliest facial expressions to appear and be mimicked in neonates. The motor resonance between infants and their caregivers is essential later in life when individuals begin to engage in increasingly complex social interactions, including play (ontogeny). The success of a playful session can be evaluated by its duration in time. Mirroring facial expressions prolongs the session by favoring individuals to fine-tune their own motor sequences accordingly (function). Finally, through a comparative approach we also demonstrate that the elements constituting play communication and mimicry are sensitive to the quality of interindividual relationships of a species, thus reflecting the nature of its social network and style (evolution). In conclusion, our goal is to integrate Tinbergen’s four areas of ethological inquiry to provide a broader framework regarding the importance of communication and mimicry in the play domain of humans and other social mammals

Physiological effects of stress-releasing behaviours in horses: the resilience hypothesis

No abstract availabl

Physiological outcomes of calming behaviors support the resilience hypothesis in horses.

To manage a stressful stimulus animals react both behaviorally and physiologically to restore the homeostasis. In stable horses, a stressful stimulus can be represented by social separation, riding discomfort or the presence of novel objects in their environment. Although Heart Rate Variability is a common indicator of stress levels in horses, the behavioral mechanisms concurrently occurring under stressful conditions are still unknown. The sudden inflation of a balloon was administered to 33 horses. Video-recording of self-directed behaviors (snore, vacuum chewing, snort, head/body shaking) and monitoring of heart activity (HR and SDRR) were conducted for five minutes before (Pre-test) and after the stimulus administration (Stress-test). During the Stress-test, only snore and vacuum chewing increased and a significant increase was also recorded in both HR and SDRR. Moreover, the snore variation between the two conditions showed a significant correlation with the variation of both HR and SDRR. With the snore acting as stress-releasing behavior to restore basal condition, the homeostasis recovered via the enactment of such behavior could be physiologically expressed by an increasing vagal activity. Hence, the capacity to maintain homeostasis (resilience) could correspond to a prevalence of parasympathetic control on heart activity, intervening when certain behaviors are performed

Relaxed open mouth reciprocity favours playful contacts in south american sea lions (Otaria flavescens)

Fine-tuning communication is well documented in mammalian social play which relies on a large variety of specific and non-specific signals. Facial expressions are one of the most frequent patterns in play communication. The reciprocity of facial signals expressed by the players provides information on their reciprocal attentional state and on the correct perception/decoding of the signal itself. Here, for the first time, we explored the Relaxed Open Mouth (ROM), a widespread playful facial expression among mammals, in the South American sea lion (Otaria flavescens). In this species, like many others, ROM appears to be used as a playful signal as distinct from merely being a biting action. ROM was often reciprocated by players. Even though ROM did not vary in frequency of emission as a function of the number of players involved, it was reciprocated more often during dyadic encounters, in which the players had the highest probability to engage in a face-to-face interaction. Finally, we found that it was the reciprocation of ROMs, more than their frequency performance, that was effective in prolonging playful bouts. In conclusion, ROM is widespread in many social mammals and O. flavescens is not an exception. At least in those species for which quantitative data are available, ROM seems to be characterized by similar design features clearly indicating that the signal underwent to similar selective pressures