| Title: | Clitoral anesthesia disrupts paced copulation in the female rat |
| Author(s): | Parada M; Sparks LM; Censi S; Pfaus JG; |
| Address: | "Center for Studies in Behavioural Neurobiology, Department of Psychology, Concordia University, Montreal, QC H4B 1R6, Canada. Electronic address: may_para@live.concordia.ca" |
| DOI: | 10.1016/j.physbeh.2013.10.018 |
| ISSN/ISBN: | 1873-507X (Electronic) 0031-9384 (Linking) |
| Abstract: | "Clitoral stimulation produced by sexual contact with a partner or during manual stimulation is associated with pleasure in humans, and produces conditioned place preference in rats. The present experiment investigated the effect of blocking genitosensory stimulation of the clitoris with lidocaine during copulation in female rats on a measure of female sexual motivation: pacing behavior. Sexually naive, ovariectomized female rats were treated with 10mug estradiol benzoate 48h and 500mug progesterone 4h prior to a 30-min copulatory trial with a sexually vigorous stimulus male scheduled every 4days. A total of 10 copulatory sessions were divided into two phases of 5 trails each. In the first phase, females received an injection (0.05ml) of either 2% lidocaine, saline, or no injection to the clitoral sheath under isoflurane anesthesia immediately prior to the start of a copulatory session, and were then placed on one side of a paced mating chamber and allowed to copulate for 30min. In the second phase, females previously injected with lidocaine were switched to saline and vice versa, and the no injection group remained the same. Variables measured included overall time spent with the males, number of solicitations, contact-return latencies following male mounts, intromissions, and ejaculations; the frequency of entrances and exits from the male chamber, and frequency of mounts, intromissions, ejaculations. Sexual behavior was examined at session 1, session 5, and session 10. At test 5, females that received LID had a greater number of entrances/exits but spent significantly less time in the presence of the male during the copulatory bout than CNTL animals. These females also displayed a trend for longer contact return latencies s after ejaculations than VEH and CNTL groups. On session 10, females that received LID and subsequently switched to VEH treatment no longer differed from controls in entrance/exit numbers, time spent with males or ejaculation contact return latency. They did however, receive a greater number of intromissions and displayed shorter inter intromission intervals compared to CNTLs. We suggest that clitoral stimulation in the rat serves as both a reward signal and may contribute to the detection of differences in copulatory stimuli that are critical to pacing and potentially, the initiation of pregnancy" |
| Keywords: | "Analysis of Variance Anesthetics, Local/*pharmacology Animals Clitoris/*drug effects/innervation Copulation/*drug effects/physiology Female Lidocaine/*pharmacology Male Ovariectomy Rats Rats, Long-Evans Time Factors Anesthesia Clitoris Paced mating Sexual;" |
| Notes: | "MedlineParada, M Sparks, L M Censi, S Pfaus, J G eng 2013/11/02 Physiol Behav. 2014 Jan 17; 123:180-6. doi: 10.1016/j.physbeh.2013.10.018. Epub 2013 Oct 29" |
