Forebrain activation during social exposure in wild-type guppies

Area of Science:

• Neuroscience
• Ethology
• Comparative Biology

Background:

• Social behavior regulation is crucial for fitness, impacting foraging and predator avoidance.
• Research has focused on complex sociality, with less attention on fundamental grouping behaviors.
• The guppy (Poecilia reticulata) serves as a model for studying social behavior in fish.

Purpose of the Study:

• To investigate the neural mechanisms underlying grouping behavior in guppies.
• To determine if brain regions involved in complex sociality also regulate grouping behavior.
• To examine shoal-elicited brain activation in guppies.

Main Methods:

• Guppies were presented with large shoals, small shoals, or no conspecifics.
• Immediate early gene expression (egr-1) was used to measure neuronal activation.
• Activation in four specific brain regions (preoptic area, ventral telencephalon parts, ventral pallium) was assessed.

Main Results:

• Increased neuronal activation was observed in the preoptic area when guppies were exposed to a large shoal compared to no social exposure.
• No significant differences in activation were found in the other examined brain regions.
• Guppies demonstrated a preference for joining larger shoals.

Conclusions:

• The preoptic area plays a significant role in regulating grouping behavior in guppies.
• This finding suggests functional homology of the preoptic area in social behavior across vertebrates.
• Other investigated brain regions may have secondary or no direct role in regulating grouping behavior.