Ultrasonic Vocalization

 

Empirical evidence suggests that ultrasonic vocalization (USV) can be used as a measure of motivational and emotional state (Knutson et al. 2002).

For instance, rodent pups emit distress USVs as a consequence of maternal severance or hypothermia (Blumberg & Alberts, 1990; Hofer & Shair, 1993; Sokoloff & Blumberg, 2005) and maternal responsiveness is proportional to the number of calls mouse pups emit (D’Amato et al. 2005). Brudzynski & Pniak (2002) observed that mature laboratory rats emit USVs in anticipation of social contact. Furthermore, USVs are produced as a result of painful stimulation during fear conditioning (Antoniadis & McDonald, 1999; Lee et al, 2001) and as a result of morphine or ethanol withdrawal (Vivian & Miczek, 1991; Moy et al. 2000, respectively).

Although the empirical evidence is somewhat inconclusive, one theory of motivation states that rat USVs can be divided between two different kHz bandwidths. Vocalizations ranging between 50-70 kHz represent positive affective states, but those in the 22 kHz range are characteristic of negative affective states (Knutson et al. 2002).

Whether or not this theory continues to garner empirical support, the evidence is clear that USVs are good indicators of underlying motivational state.

Therefore, our USV system is designed for behavioral applications, and is an affordable solution for accurately measuring both the amplitude and frequency of these ultrasonic vocalizations emitted by laboratory rodents.


Designed to measure motivational behavior in paradigms such as:

  • Drug addiction
  • Mother-pup separation
  • Isolation stress
  • Social interactions
  • Sexual encounters
  • …and more

 

Distress Call

  • Neonatal rat pups emit distress USVs at the average frequency of 40 kHz (Sokoloff & Blumberg, 2005) and this frequency decreases with age.
  • Mature rats produce long calls that are just above the audible range at 22 kHz (65-85 dB), and these calls last for 300-4000 ms and have a narrow bandwidth of 1-6 kHz (Sales 1972).

Alarm Call (22 kHz)
Communicates the presence of a predator or are produced as the result of experiencing a painful event (Blanchard et al. 1991; Antoniadis & McDonald, 1999; respectively).

Short Call (32-96 kHz, 30-65 ms)

  • Occurs during high levels of physical activity, arousal, and social contact (Knutson et al. 1998).

Long Call

  • Associated with sexual behavior and aggression (Barfield et al 1979).