A Protocol for the Non-invasive Method of Ultrasound Separation During the Sociosexual Vocal-Non-contact Model in Rats

Abstract

Ultrasonic vocalization (USV) is one of the measurable behavioral parameters of sociosexual interactions in rats. To precisely and accurately describe the neurobehavioral properties of USV and the potentially related specific emotional responsiveness of animals, we need to know which animals vocalize and what is their exact behavioral and physiological response. To this end, we modified the non-contact cage [non-contact erection model (NCE)] by adding a modification [vocalization-non-contact erection (VOC-NCE)] that makes it possible to assign emitted ultrasonic signals to a particular animal. Typically, the NCE cage consists of two compartments separated by perforated baffles. A male is placed in one section, and a receptive female is placed in the other section. This makes possible the accurate description of sexual parameters related to the cues controlled by the experimenter. In VOC-NCE, we completely separated the male USV from the female USV by three appropriately perforated baffles and located microphones combined with ultrasonic screening. We recorded emission in both typical bands, the so-called 22- and 50-kHz bands, with various subtypes, thus highlighting the utility of our protocol to investigate the sexual dimorphism of vocalization. Similar to the anticipatory model, we showed that emission can occur without acoustic feedback from concomitants during the VOC-NCE test. Therefore, we propose a relatively simple method for assigning individual vocalization. We discuss its usefulness and limitations in assessing vocal differentiation related to sexual parameters, adaptive changes during conditioning procedures, and further applications.

Neuronal, affective, and sensory correlates of targeted helping behavior in male and female Sprague Dawley rats

“…Further, the distinction of distress from appetitive calls may not be as concise in complex prosocial behaviors, making strong conclusions difficult. For example, the canonical 22 kHz distress call is often observed in the post-ejaculation period in male rats ( Bialy et al, 2016 ), calling the distinct grouping of these calls into question ( Bogacki-Rychlik et al, 2022 ). However, taken together, these experiments indicate sex differences are present in sensory and affective communication, especially early in acquisition when release is less frequent.…”

Neurophysiology of male sexual arousal—Behavioral perspective

“…As always, subjective and objective parts of emotional responsiveness are challenging during their separation. Previously, it has been described that detailed ultrasonic vocalization analysis could serve as an additional parameter depicting these components ( Barfield et al, 1979 ; Bogacki-Rychlik et al, 2021 , 2022 ).…”

“… Scheme of the chamber for the NCE test. Based on Sachs et al (1994) and Bogacki-Rychlik et al (2022) . …”

“…To reduce the influence of auditory ultrasonic vocalizations, an additional barrier above the chamber eliminates the detection of vocalizations emitted by another animal ( Bogacki-Rychlik et al, 2022 ).…”