DAILY RHYTHMS OF VOCALIZATION CALLS IN MARMOSETS.

VIEIRA C; SIMÕES C; VALENTINUZZI VS; ARAÚJO JF

Natal, RN, Brasil

Congreso; II Simpósio do Instituto Internacional de Neurociência de Natal-IINN; 2007

Instituto Internacional de Neurociência de Natal-IINN

Circadian rhythmicity is expressed in diverse behaviors and physiological variables. Insects, frogs, and birds show this type of temporal expression in their songs as well as in other forms of communication. Since vocalizations are important for species identification and mating, we registered the daily rhythmicity of vocalization calls in Callithrix jacchus. Six subjects were individually housed in the laboratory under a 12:12h light-dark cycle (lights on: 06:00), with sound level and temperature controlled. During a month, general activity was registered by infrared sensors in 5-min intervals and vocalizations were constantly recorded using the Sound Analysis Pro (SA+). Each sound file was read and was determined the number of sound file by hour and total durantion of the sound by hour. The number of sound files per hour was determined as well as the duration of each sound.  The El Temps software was used to evaluate the locomotor activity rhythmic parameters. This activity rhythm showed a diurnal bimodal pattern. The most frequent vocalization was PHEE, with a duration of 0.7 ? 1.2 sec, and fundamental frequencies between 6.5 and 8.5 KHz. This sound ocurred most frequentely during the early morning (acrophase between 0620 and 0800; ANOVA + Scheffe post hoc test showed that the frequency and duration of the vocalization were greater at 0600 and 0700 when compared with other light-phase times). These results strongly suggest a daily rhythmic expression in the vocalization calls of marmosets. Currently we are analyzing in more detail these results in order to understand the potential ecological and physiological bases of this rhythm.   Financial support: CNPq, FAPERN.