Social and Ecological Regulation of a Decision-Making Circuit

2010 ◽  
Vol 104 (6) ◽  
pp. 3180-3188 ◽  
Author(s):  
H. Neumeister ◽  
K. W. Whitaker ◽  
H. A. Hofmann ◽  
T. Preuss
Keyword(s):  
Decision Making ◽  
Predation Risk ◽  
Neural Circuit ◽  
Physiological State ◽  
Cichlid Fish ◽  
M Cell ◽  
Body Coloration ◽  
Cryptic Coloration ◽  
Electrophysiological Recordings ◽  
Astatotilapia Burtoni

Ecological context, sensory inputs, and the internal physiological state are all factors that need to be integrated for an animal to make appropriate behavioral decisions. However, these factors have rarely been studied in the same system. In the African cichlid fish Astatotilapia burtoni, males alternate between two phenotypes based on position in a social hierarchy. When dominant (DOM), fish display bright body coloration and a wealth of aggressive and reproductive behavioral patterns that make them conspicuous to predators. Subordinate (SUB) males, on the other hand, decrease predation risk by adopting cryptic coloration and schooling behavior. We therefore hypothesized that DOMs would show enhanced startle-escape responsiveness to compensate for their increased predation risk. Indeed, behavioral responses to sound clicks of various intensities showed a significantly higher mean startle rate in DOMs compared with SUBs. Electrophysiological recordings from the Mauthner cells (M-cells), the neurons triggering startle, were performed in anesthetized animals and showed larger synaptic responses to sound clicks in DOMs, consistent with the behavioral results. In addition, the inhibitory drive mediated by interneurons (passive hyperpolarizing potential [PHP] cells) presynaptic to the M-cell was significantly reduced in DOMs. Taken together, the results suggest that the likelihood for an escape to occur for a given auditory stimulus is higher in DOMs because of a more excitable M-cell. More broadly, this study provides an integrative explanation of an ecological and social trade-off at the level of an identifiable decision-making neural circuit.

scholarly journals The melanocortin system regulates body pigmentation and social behaviour in a colour polymorphic cichlid fish

2017 ◽  
Vol 284 (1851) ◽  
pp. 20162838 ◽  
Author(s):  
Peter D. Dijkstra ◽  
Sean M. Maguire ◽  
Rayna M. Harris ◽  
Agosto A. Rodriguez ◽  
Ross S. DeAngelis ◽  
...  
Keyword(s):  
Cichlid Fish ◽  
Specific Effect ◽  
The Body ◽  
Melanocortin Receptors ◽  
Melanocortin System ◽  
Melanocyte Stimulating Hormone ◽  
Body Coloration ◽  
Astatotilapia Burtoni ◽  
Specific Regulation ◽  
Colour Morphs

The melanocortin system is a neuroendocrine system that regulates a range of physiological and behavioural processes. We examined the extent to which the melanocortin system simultaneously regulates colour and behaviour in the cichlid fish Astatotilapia burtoni . We found that yellow males are more aggressive than blue males, in line with previous studies. We then found that exogenous α-melanocyte-stimulating hormone (α-MSH) increases yellowness of the body and dispersal of xanthophore pigments in both morphs. However, α-MSH had a morph-specific effect on aggression, with only blue males showing an increase in the rate of aggression. Exogenous agouti signalling peptide (ASIP), a melanocortin antagonist, did not affect coloration but reduced the rate of aggression in both colour morphs. Blue males had higher cortisol levels than yellow males. Neural gene expression of melanocortin receptors ( mcr ) and ligands was not differentially regulated between colour morphs. In the skin, however, mc1r and pro-opiomelanocortin ( pomc ) β were upregulated in blue males, while asip 1 was upregulated in yellow males. The effects of α-MSH on behaviour and body coloration, combined with morph-specific regulation of the stress response and the melanocortin system, suggest that the melanocortin system contributes to the polymorphism in behaviour and coloration in A. burtoni .

Serotonergic modulation of startle-escape plasticity in an African cichlid fish: a single-cell molecular and physiological analysis of a vital neural circuit

2011 ◽  
Vol 106 (1) ◽  
pp. 127-137 ◽  
Author(s):  
K. W. Whitaker ◽  
H. Neumeister ◽  
L. S. Huffman ◽  
C. E. Kidd ◽  
T. Preuss ◽  
...  
Keyword(s):  
Single Cell ◽  
Social Life ◽  
Neural Circuit ◽  
Escape Behavior ◽  
Cichlid Fish ◽  
Receptor Subtype ◽  
M Cells ◽  
M Cell ◽  
Trade Off ◽  
Electrophysiological Properties

Social life affects brain function at all levels, including gene expression, neurochemical balance, and neural circuits. We have previously shown that in the cichlid fish Astatotilapia burtoni brightly colored, socially dominant (DOM) males face a trade-off between reproductive opportunities and increased predation risk. Compared with camouflaged subordinate (SUB) males, DOMs exposed to a loud sound pip display higher startle responsiveness and increased excitability of the Mauthner cell (M-cell) circuit that governs this behavior. Using behavioral tests, intracellular recordings, and single-cell molecular analysis, we show here that serotonin (5-HT) modulates this socially regulated plasticity via the 5-HT receptor subtype 2 (5-HTR2). Specifically, SUBs display increased sensitivity to pharmacological manipulation of 5-HTR2 compared with DOMs in both startle-escape behavior and electrophysiological properties of the M-cell. Immunohistochemistry showed serotonergic varicosities around the M-cells, further suggesting that 5-HT impinges directly onto the startle-escape circuitry. To determine whether the effects of 5-HTR2 are pre- or postsynaptic, and whether other 5-HTR subtypes are involved, we harvested the mRNA from single M-cells via cytoplasmic aspiration and found that 5-HTR subtypes 5A and 6 are expressed in the M-cell. 5-HTR2, however, was absent, suggesting that it affects M-cell excitability through a presynaptic mechanism. These results are consistent with a role for 5-HT in modulating startle plasticity and increase our understanding of the neural and molecular basis of a trade-off between reproduction and predation.

scholarly journals Inhibition within a premotor circuit controls the timing of vocal turn-taking in zebra finches

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan I. Benichov ◽  
Daniela Vallentin
Keyword(s):  
Neural Circuit ◽  
Zebra Finches ◽  
Vocal Responses ◽  
Local Inhibition ◽  
Impaired Ability ◽  
Neuron Activation ◽  
Electrophysiological Recordings ◽  
Vocal Signals ◽  
Turn Taking ◽  
Pharmacological Manipulations

AbstractVocal turn-taking is a fundamental organizing principle of human conversation but the neural circuit mechanisms that structure coordinated vocal interactions are unknown. The ability to exchange vocalizations in an alternating fashion is also exhibited by other species, including zebra finches. With a combination of behavioral testing, electrophysiological recordings, and pharmacological manipulations we demonstrate that activity within a cortical premotor nucleus orchestrates the timing of calls in socially interacting zebra finches. Within this circuit, local inhibition precedes premotor neuron activation associated with calling. Blocking inhibition results in faster vocal responses as well as an impaired ability to flexibly avoid overlapping with a partner. These results support a working model in which premotor inhibition regulates context-dependent timing of vocalizations and enables the precise interleaving of vocal signals during turn-taking.

scholarly journals Reward activity in ventral pallidum tracks satiety-sensitive preference and drives choice behavior

2020 ◽  
Vol 6 (45) ◽  
pp. eabc9321
Author(s):  
David J. Ottenheimer ◽  
Karen Wang ◽  
Xiao Tong ◽  
Kurt M. Fraser ◽  
Jocelyn M. Richard ◽  
...  
Keyword(s):  
Decision Making ◽  
Nervous System ◽  
Prediction Error ◽  
Choice Behavior ◽  
Physiological State ◽  
Ventral Pallidum ◽  
Optogenetic Stimulation ◽  
Reward Prediction ◽  
Behavioral Preference ◽  
Stimulation Of

A key function of the nervous system is producing adaptive behavior across changing conditions, like physiological state. Although states like thirst and hunger are known to impact decision-making, the neurobiology of this phenomenon has been studied minimally. Here, we tracked evolving preference for sucrose and water as rats proceeded from a thirsty to sated state. As rats shifted from water choices to sucrose choices across the session, the activity of a majority of neurons in the ventral pallidum, a region crucial for reward-related behaviors, closely matched the evolving behavioral preference. The timing of this signal followed the pattern of a reward prediction error, occurring at the cue or the reward depending on when reward identity was revealed. Additionally, optogenetic stimulation of ventral pallidum neurons at the time of reward was able to reverse behavioral preference. Our results suggest that ventral pallidum neurons guide reward-related decisions across changing physiological states.

scholarly journals Ants show a leftward turning bias when exploring unknown nest sites

2014 ◽  
Vol 10 (12) ◽  
pp. 20140945 ◽  
Author(s):  
Edmund R. Hunt ◽  
Thomas O'Shea-Wheller ◽  
Gregory F. Albery ◽  
Tamsyn H. Bridger ◽  
Mike Gumn ◽  
...  
Keyword(s):  
Decision Making ◽  
Predation Risk ◽  
Temnothorax Albipennis ◽  
Present Evidence ◽  
Nest Sites ◽  
Migration Factors ◽  
Important Field ◽  
And Migration ◽  
Wall Following ◽  
Colony Level

Behavioural lateralization in invertebrates is an important field of study because it may provide insights into the early origins of lateralization seen in a diversity of organisms. Here, we present evidence for a leftward turning bias in Temnothorax albipennis ants exploring nest cavities and in branching mazes, where the bias is initially obscured by thigmotaxis (wall-following) behaviour. Forward travel with a consistent turning bias in either direction is an effective nest exploration method, and a simple decision-making heuristic to employ when faced with multiple directional choices. Replication of the same bias at the colony level would also reduce individual predation risk through aggregation effects, and may lead to a faster attainment of a quorum threshold for nest migration. We suggest the turning bias may be the result of an evolutionary interplay between vision, exploration and migration factors, promoted by the ants' eusociality.

scholarly journals Heritability and adaptive significance of the number of egg-dummies in the cichlid fish Astatotilapia burtoni

2011 ◽  
Vol 278 (1716) ◽  
pp. 2318-2324 ◽  
Author(s):  
Topi K. Lehtonen ◽  
Axel Meyer
Keyword(s):  
Species Recognition ◽  
Cichlid Fish ◽  
Fertilization Success ◽  
Narrow Sense Heritability ◽  
Key Innovation ◽  
Bright Spots ◽  
Spot Number ◽  
Astatotilapia Burtoni ◽  
Important Trait ◽  
High Degree

Cichlid fishes are a textbook example of rapid speciation and exuberant diversity—this applies especially to haplochromines, a lineage with approximately 1800 species. Haplochromine males uniquely possess oval, bright spots on their anal fin, called ‘egg-spots’ or ‘egg-dummies’. These are presumed to be an evolutionary key innovation that contributed to the tribe's evolutionary success. Egg-spots have been proposed to mimic the ova of the mouthbrooding females of the corresponding species, contribute to fertilization success and even facilitate species recognition. Interestingly, egg-spot number varies extensively not only between species, but also within some populations. This high degree of intraspecific variation may appear to be counterintuitive since selection might be expected to act to stabilize traits that are correlated with fitness measures. We addressed this ‘paradox’ experimentally, and found that in the haplochromine cichlid Astatotilapia burtoni , the number of egg-spots was related to male age, body condition and dominance status. Intriguingly, the egg-spot number also had a high heritable component (narrow sense heritability of 0.5). These results suggest that the function of egg-spots might have less to do with fertilization success or species recognition, but rather relate to mate choice and/or male–male competition, helping to explain the high variability in this important trait.

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