The effect of infant vocalization in alloparental responsiveness of common marmosets (Callithrix jacchus)

Abstract

Among mammals, alloparental care can be influenced by hormones as well as by previous experience and sensory stimuli from the infants, such as sight and sound, smell, and physical contact with the infant. To determine the responsiveness of common marmoset (Callithrix jacchus) nonreproductive females and males with and without previous experience in caretaking to infant sensory cues, we exposed 12 females and 12 males to vocalization recordings for 10 min under two conditions: (1) exposure to adult conspecific vocalization recordings, and (2) exposure to infant vocalization recordings. We recorded the frequency of approach toward the sound source, the time spent near it and locomotion frequency of males and females in the cage under both conditions. Blood samples were collected after each test for cortisol measuring by EIA method. The infant vocalization affects the behavioral and hormonal responses of males and females of common marmosets. The animals approached and spent more time near the sound source and showed an increase in locomotion during infant vocalization exposure compared to the adult vocalization. However, there was no significant difference in the behavioral response of animals when previous experience and the sex were taken into account. In both sexes, cortisol levels were significantly higher following infant vocalization exposure compared to the adult vocalization. These findings suggest that the infant vocalization appears to be an effective cue that facilitates the approach of the caregiver and maintaining their responsiveness and that the cortisol seems to be important for alertness to sensory stimuli, modulating their motivation to interact with the infant.

Vasopressin, but not oxytocin, modulates responses to infant stimuli in marmosets providing care to dependent infants

“…An explanation for the fact that neither of the hypotheses were fully supported may be that AVP and OT altered responses to a potentially anxiety-inducing testing situation in addition to infantspecific responses. Exposure to infant vocalizations alone increases plasma cortisol in marmosets (Barbosa et al, 2017), and it is likely that the capture and removal from the home cage induced some level of stress on the subjects. In general, OT tends to act as an anxiolytic and AVP tends to be anxiogenic and aggressogenic (Neumann, 2008;Neumann & Slattery, 2016;Takayanagi et al, 2005;Viviani & Stoop, 2008), though there are important sex and species differences in the expression of aggression (Been, Gibbons, & Meisel, 2018;Terranova, Ferris, & Albers, 2017).…”

“…Similarly, parentally inexperienced male marmosets initially show an inhibited response to infants and infant stimuli, but with repeated exposure rapidly increase their approach and caregiving behavior to equally experienced marmosets (Barbosa, Mota, & Barbosa, 2017;Barbosa & Da Silva Mota, 2013). Thus, exposure to and experience caring for young are critical determinants of caregiving behavior, even in those individuals that do not experience pregnancy and parturition themselves.…”

“…Exposure to young clearly produces changes in caregiving behavior, but there remains a question of whether these changes are permanent and stable, or are dynamic and dependent on the individual's current demand for caregiving behavior. Experience effects, in particular those that demonstrate enhancements in care from the first litter to the second (Barbosa et al., 2017;Barbosa & Da Silva Mota, 2013;Perea-Rodriguez et al, 2015) or those that result from exposure to younger siblings (Kelley, Castelli, Mabry, & Solomon, 2013;Salo & French, 1989;Stone et al, 2010;Tardif et al, 1984) suggest that these changes are permanent. However there is evidence that caregiving behavior, and the underlying neurobiology that mediates these changes, are responsive to differences in parenting demand.…”

“…Sexually naïve female rats and mice initially fail to care for unrelated pups, but repeated exposure to pups will show spontaneous caregiving behavior (Okabe, Kitano, Nagasawa, Mogi, & Kikusui, ; Okabe et al, ; Rosenblatt, Hazelwood, & Poole, ; Stolzenberg & Champagne, ). Similarly, parentally inexperienced male marmosets initially show an inhibited response to infants and infant stimuli, but with repeated exposure rapidly increase their approach and caregiving behavior to equally experienced marmosets (Barbosa, Mota, & Barbosa, ; Barbosa & Da Silva Mota, ). Thus, exposure to and experience caring for young are critical determinants of caregiving behavior, even in those individuals that do not experience pregnancy and parturition themselves.…”