Movement Trend Alterations in the Periaqueductal Gray(PAG)-Employed Ratbot Navigation Are Correlated with Stimulation Parameters

In previous studies,Periaqueductal Gray(PAG)stimulation was used to stop ratbots from moving.Due to the homology between the PAG and the intercollicular nucleus,which has been used for forward movement in birds,we investigated the possibility of PAG application to induce forward locomotion for the first time.Using a corridor maze,the traveled distances via PAG electrical stimulation were examined in nine Wistar male rats during three sessions.A custom-designed stimulator was developed to apply the stimulation.The results showed reductions in responses to stimulation over time.Accordingly,the traveled distances had negative slopes during the consecutive trials(in 8 out of the 9 rats),and the slope mean was significantly different from zero.There was a strong correlation between the stimulation parameters(electric Charge per Phase(CPP)and the Number of Pulses(NP))and the observed slopes.The negative Movement Slopes(MS)were highly correlated with the CPP and the NP,as the Pearson's linear correlation coefficients were−0.87 and−0.79,respectively.The MS-CPP coefficients of determination(R-squared)were also between 0.76 and 0.95.In addition,the MS-NP coefficients of determination were between 0.63 and 0.87.Thus,it is concluded that the electrical stimulation parameters influence the behavioral outcomes directly.Furthermore,the PAG area may be considered a suitable candidate for forward locomotion control in the future if the area is harnessed effectively to prevent undesirable chaotic behaviors.

Together We Stand-Analyzing Schooling Behavior in Naive Newborn Guppies through Biorobotic Predators

A major advantage of animal aggregations concerns cooperative antipredator strategies.Schooling behavior emerges earlier in many fish species,especially in those cannibalizing their offspring.Experience is fundamental for developing schooling behavior.However,the cognitive ability of naive newborn fish to aggregate remains unclear.Herein,Poecilia reticulata,was selected as model organism to investigate how combinations of biomimetic robotic agents and adult conspecific olfactory cues affect collective responses in newborns.The role of white and brown backgrounds in evoking aggregations was also assessed.Olfactory cues were sufficient for triggering aggregations in P.reticulata newborns,although robotic agents had a higher influence on the group coalescence.The combination of robotic agents and olfactory cues increased schooling behavior duration.Notably,schooling was longer in the escape compartment when robotic agents were presented,except for the combination of the male-mimicking robotic fish plus adult guppy olfactory cues,with longer schooling behavior in the exploring compartment.Regardless of the tested cues,newborn fish aggregated preferentially on the brown areas of the arena.Overall,this research provides novel insights on the early collective cognitive ability of newborn fish,paving the way to the use of biomimetic robots in behavioral ecology experiments,as substitutes for real predators.