scholarly journals Brain nonapeptide levels are related to social status and affiliative behaviour in a cooperatively breeding cichlid fish

2015 ◽  
Vol 2 (2) ◽  
pp. 140072 ◽  
Author(s):  
Adam R. Reddon ◽  
Constance M. O'Connor ◽  
Susan E. Marsh-Rollo ◽  
Sigal Balshine ◽  
Magdalena Gozdowska ◽  
...  

The mammalian nonapeptide hormones, vasopressin and oxytocin, are known to be potent regulators of social behaviour. Teleost fishes possess vasopressin and oxytocin homologues known as arginine vasotocin (AVT) and isotocin (IT), respectively. The role of these homologous nonapeptides in mediating social behaviour in fishes has received far less attention. The extraordinarily large number of teleost fish species and the impressive diversity of their social systems provide us with a rich test bed for investigating the role of nonapeptides in regulating social behaviour. Existing studies, mostly focused on AVT, have revealed relationships between the nonapeptides, and both social behaviour and dominance status in fishes. To date, much of the work on endogenous nonapeptides in fish brains has measured genomic or neuroanatomical proxies of nonapeptide production rather than the levels of these molecules in the brain. In this study, we measure biologically available AVT and IT levels in the brains of Neolamprologus pulcher , a cooperatively breeding cichlid fish, using high performance liquid chromatography with fluorescence detection. We found that brain AVT levels were higher in the subordinate than in dominant animals, and levels of IT correlated negatively with the expression of affiliative behaviour. We contrast these results with previous studies, and we discuss the role the nonapeptide hormones may play in the regulation of social behaviour in this highly social animal.

2015 ◽  
Vol 85 (3) ◽  
pp. 203-213 ◽  
Author(s):  
Olinda Almeida ◽  
Rui F. Oliveira

The nonapeptide arginine vasotocin (AVT) and its mammalian homologue arginine vasopressin play a key role in the regulation of social behaviour across vertebrates. In teleost fishes, three AVT neuronal populations have been described in the preoptic area (POA): the parvocellular (pPOA), the magnocellular (mPOA) and the gigantocellular (gPOA). Neurons from each of these areas project both to the pituitary and to other brain regions, where AVT is supposed to regulate neural circuits underlying social behaviour. However, in the fish species studied so far, there is considerable variation in which AVT neuronal populations are involved in behavioural modulation and in the direction of the effect. In this study, the association between AVT neuronal phenotypes and social status was investigated in the Mozambique tilapia (Oreochromis mossambicus). This species is an African female mouth-brooding cichlid fish in which males form breeding aggregations in which dominant males establish territories and subordinate males to act as floaters. With respect to sex differences in AVT neuronal phenotypes, females have a larger number of AVT neurons in the pPOA and mPOA. Within males, AVT appeared associated with social subordination, as indicated by the larger cell body areas of AVT neurons in mPOA and gPOA nuclei of non-territorial males. There were also positive correlations between submissive behaviour and the soma size of AVT cells in all three nuclei and AVT cell number in the mPOA. In summary, the results provide evidence for an involvement of AVT in the modulation of social behaviour in tilapia, but it was not possible to identify specific roles for specific AVT neuronal populations. The results presented here also contrast with those previously published for another cichlid species with a similar mating system, which highlights the species-specific nature of the pattern of association between AVT and social behaviour even within the same taxonomic family.


2020 ◽  
Author(s):  
Beau A. Alward ◽  
Vibhav Laud ◽  
Christopher J. Skalnik ◽  
Ryan A. York ◽  
Scott Juntti ◽  
...  

AbstractSocial hierarchies are ubiquitous in social species and profoundly influence physiology and behavior. Androgens like testosterone have been strongly linked to social status, yet the molecular mechanisms regulating social status are not known. The African cichlid fish Astatotilapia burtoni is a powerful model species for elucidating the role of androgens in social status given their rich social hierarchy and genetic tractability. Dominant A. burtoni males possess large testes, bright coloration, and perform aggressive and reproductive behaviors while non-dominant males do not. Social status in A. burtoni is in flux, however, as males alter their status depending on the social environment. Due to a teleost-specific whole-genome duplication, A. burtoni possess two androgen receptor (AR) paralogs, ARα and ARβ, providing a unique opportunity to disentangle the role of gene duplication in the evolution of social systems. Here, we used CRISPR/Cas9 gene editing to generate AR mutant A. burtoni and performed a suite of experiments to interrogate the mechanistic basis of social dominance. We find that ARβ, but not ARα, is required for testes growth and bright coloration, while ARα, but not ARβ, is required for the performance of reproductive behavior and aggressive displays. Both receptors are required to reduce flees from females and either AR is sufficient for attacking males. Thus, social status in A. burtoni is inordinately dissociable and under the modular control of two AR paralogs. This type of non-redundancy may be important in facilitating social plasticity in A. burtoni and other species whose social status relies on social experience.Significance StatementSocial rank along a hierarchy determines physiological state and behavioral performance. A ubiquitous feature of social hierarchies is the communication of rank through non-physical signaling systems (e.g., coloration) and aggression, traits that correlate with the reproductive status of an individual. Despite the links identified between social status, physiology, and behavior, the molecular basis of social status is not known. Here, we genetically dissect social status in the African cichlid fish Astatotilapia burtoni using CRISPR/Cas9 gene editing. We show that two distinct androgen receptor (AR) genes control social status in a highly modular manner. This type of coordination of social status may be fundamental across species that rely on social information to optimally guide physiology and behavior.


Behaviour ◽  
1998 ◽  
Vol 135 (3) ◽  
pp. 369-386 ◽  
Author(s):  
Sigal Balshine-Earn ◽  
Arnon Lotem

AbstractMost theories of social behaviour and cooperation assume that animals can recognise other individuals, but this is rarefy tested. Using Neolamprologus brichardi, a cooperatively breeding cichlid fish, we monitored behavioural responses to (1) real fish versus video images of fish; (2) mate versus neighbour and (3) video images of mate versus video image of neighbour. All tests were controlled for size and sex. Fish reacted appropriately to the playbacks, although responses to videos were not as strong as to real fish. Both males and females fought against the images of stranger and neighbour fish and they courted images of mates. These results confirm that the cooperatively breeding fish, Neolamprologus brichardi, recognises individuals based on vision and that video playbacks contain sufficient information to facilitate recognition.


2017 ◽  
Vol 4 (5) ◽  
pp. 170350 ◽  
Author(s):  
Adam R. Reddon ◽  
Constance M. O'Connor ◽  
Erin Nesjan ◽  
Jason Cameron ◽  
Jennifer K. Hellmann ◽  
...  

Social living has evolved numerous times across a diverse array of animal taxa. An open question is how the transition to a social lifestyle has shaped, and been shaped by, the underlying neurohormonal machinery of social behaviour. The nonapeptide neurohormones, implicated in the regulation of social behaviours, are prime candidates for the neuroendocrine substrates of social evolution. Here, we examined the brains of eight cichlid fish species with divergent social systems, comparing the number and size of preoptic neurons that express the nonapeptides isotocin and vasotocin. While controlling for the influence of phylogeny and body size, we found that the highly social cooperatively breeding species ( n  = 4) had fewer parvocellular isotocin neurons than the less social independently breeding species ( n  = 4), suggesting that the evolutionary transition to group living and cooperative breeding was associated with a reduction in the number of these neurons. In a complementary analysis, we found that the size and number of isotocin neurons significantly differentiated the cooperatively breeding from the independently breeding species. Our results suggest that isotocin is related to sociality in cichlids and may provide a mechanistic substrate for the evolution of sociality.


2020 ◽  
Vol 117 (45) ◽  
pp. 28167-28174
Author(s):  
Beau A. Alward ◽  
Vibhav A. Laud ◽  
Christopher J. Skalnik ◽  
Ryan A. York ◽  
Scott A. Juntti ◽  
...  

Social hierarchies are ubiquitous in social species and profoundly influence physiology and behavior. Androgens like testosterone have been strongly linked to social status, yet the molecular mechanisms regulating social status are not known. The African cichlid fishAstatotilapia burtoniis a powerful model species for elucidating the role of androgens in social status given their rich social hierarchy and genetic tractability. DominantA. burtonimales possess large testes and bright coloration and perform aggressive and reproductive behaviors while nondominant males do not. Social status inA. burtoniis in flux, however, as males alter their status depending on the social environment. Due to a teleost-specific whole-genome duplication,A. burtonipossess two androgen receptor (AR) paralogs,ARαandARβ, providing a unique opportunity to disentangle the role of gene duplication in the evolution of social systems. Here, we used CRISPR/Cas9 gene editing to generate AR mutantA. burtoniand performed a suite of experiments to interrogate the mechanistic basis of social dominance. We find thatARβ,but notARα, is required for testes growth and bright coloration, whileARα, but notARβ, is required for the performance of reproductive behavior and aggressive displays. Both receptors are required to reduce flees from females and either AR is sufficient for attacking males. Thus, social status inA. burtoniis inordinately dissociable and under the modular control of two AR paralogs. This type of nonredundancy may be important in facilitating social plasticity inA. burtoniand other species whose social status relies on social experience.


Author(s):  
J.E. Johnson

Although neuroaxonal dystrophy (NAD) has been examined by light and electron microscopy for years, the nature of the components in the dystrophic axons is not well understood. The present report examines nucleus gracilis and cuneatus (the dorsal column nuclei) in the brain stem of aging mice.Mice (C57BL/6J) were sacrificed by aldehyde perfusion at ages ranging from 3 months to 23 months. Several brain areas and parts of other organs were processed for electron microscopy.At 3 months of age, very little evidence of NAD can be discerned by light microscopy. At the EM level, a few axons are found to contain dystrophic material. By 23 months of age, the entire nucleus gracilis is filled with dystrophic axons. Much less NAD is seen in nucleus cuneatus by comparison. The most recurrent pattern of NAD is an enlarged profile, in the center of which is a mass of reticulated material (reticulated portion; or RP).


Author(s):  
D. E. Newbury ◽  
R. D. Leapman

Trace constituents, which can be very loosely defined as those present at concentration levels below 1 percent, often exert influence on structure, properties, and performance far greater than what might be estimated from their proportion alone. Defining the role of trace constituents in the microstructure, or indeed even determining their location, makes great demands on the available array of microanalytical tools. These demands become increasingly more challenging as the dimensions of the volume element to be probed become smaller. For example, a cubic volume element of silicon with an edge dimension of 1 micrometer contains approximately 5×1010 atoms. High performance secondary ion mass spectrometry (SIMS) can be used to measure trace constituents to levels of hundreds of parts per billion from such a volume element (e. g., detection of at least 100 atoms to give 10% reproducibility with an overall detection efficiency of 1%, considering ionization, transmission, and counting).


2001 ◽  
Vol 17 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Juan Botella ◽  
María José Contreras ◽  
Pei-Chun Shih ◽  
Víctor Rubio

Summary: Deterioration in performance associated with decreased ability to sustain attention may be found in long and tedious task sessions. The necessity for assessing a number of psychological dimensions in a single session often demands “short” tests capable of assessing individual differences in abilities such as vigilance and maintenance of high performance levels. In the present paper two tasks were selected as candidates for playing this role, the Abbreviated Vigilance Task (AVT) by Temple, Warm, Dember, LaGrange and Matthews (1996) and the Continuous Attention Test (CAT) by Tiplady (1992) . However, when applied to a sample of 829 candidates in a job-selection process for air-traffic controllers, neither of them showed discriminative capacity. In a second study, an extended version of the CAT was applied to a similar sample of 667 subjects, but also proved incapable of properly detecting individual differences. In short, at least in a selection context such as that studied here, neither of the tasks appeared appropriate for playing the role of a “short” test for discriminating individual differences in performance deterioration in sustained attention.


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