Serotonin impairs copulation and attenuates ejaculation-induced glutamate activity in the medial preoptic area.

The medial preoptic area (MPOA) is critical for male sexual behavior. Glutamate is released in the MPOA of male rats during copulation, and increasing glutamate levels by reverse dialysis of glutamate uptake inhibitors facilitates mating. Conversely, increased release of serotonin (5-HT) inhibits sexual behavior. In both rats and men, selective serotonin reuptake inhibitors (SSRIs) impair erection, ejaculation, and libido. Here we reverse-dialyzed 5-HT through concentric microdialysis probes in the MPOA of male rats; concurrently we collected 2-min samples for analysis of glutamate and measured sexual behavior. Sexual activity, and especially ejaculation, increased levels of glutamate in the MPOA. However, reverse dialysis of 5-HT into the MPOA impaired ejaculatory ability and attenuated glutamate release. Implications of these results for impairment of sexual behavior that results from administration of SSRIs are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mating activates NMDA receptors in the medial preoptic area of male rats.

Studies have emphasized the role of the medial preoptic area (MPOA) as an important site for the regulation of male sexual behavior. Indeed, ablations of the MPOA impair sexual behavior, whereas stimulation of the MPOA enhances behavior. Furthermore, neural activity in the MPOA increases with mating. The current study tested the hypothesis that activation of N-methyl-D-aspartate (NMDA) receptors occurs in MPOA neurons and is essential for the expression of male sexual behavior in rats. Results indicate that nearly all MPOA neurons that expressed Fos following mating also contained the NR1 subunit of NMDA receptors. Furthermore, mating increased phosphorylation, thus activation, of NR1 in the MPOA. Additionally, blocking NMDA receptors significantly decreased mating-induced Fos expression and mating-induced phosphorylation of NMDA receptors and impaired male sexual behavior. These results provide evidence that mating activates NMDA receptors in the MPOA and that this activation is important for the expression of male sexual behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The substrate for brain-stimulation reward in the lateral preoptic area: III. Connections to the lateral hypothalamic area.

Double-pulse tests were used to estimate the refractory periods and anatomical linkage of the reward-relevant fibers that course between the lateral preoptic and lateral hypothalamic areas. In the 1st study, pairs of conditioning and test pulses were delivered to each site, and the interval between pulses varied; recovery from refractoriness was similar at both sites, with the curves generally rising from 0.6 to 2.0 ms. In the 2nd study, the pairs of pulses were delivered to both sites. Six of 7 rats showed evidence of axonal collision, with estimates of conduction velocity that ranged from 0.48 to 8.95 m/s across rats. These results suggest that a wide spectrum of fiber types characterizes the reward-relevant axons that course uninterruptedly between these 2 regions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estrogen and the neural mediation of female–male mounting in the rat.

Sexually receptive females mount sexually sluggish males to entice them to copulate, and estrogen and male olfactory cues mediate this female–male mounting (FMM) in the rat. This study examined whether brain regions that concentrate steroid hormones and receive olfactory projections were important for the mediation of FMM. Fos induction was observed within the medial amygdala, medial preoptic area, and ventromedial hypothalamus of ovariectomized, hormone-primed rats that displayed FMM compared with rats that did not. Excitotoxic lesions of those regions eliminated FMM, whereas implants of crystalline estradiol benzoate to the ventromedial hypothalamus, but not the medial preoptic area or medial amygdala, restored FMM. These data indicate that the ventromedial hypothalamus is a critical area of convergence of hormonal, olfactory, and somatosensory inputs for FMM. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dopamine D? receptor stimulation of the nucleus accumbens or the medial preoptic area promotes the onset of maternal behavior in pregnancy-terminated rats.

There is good evidence that interference with the mesolimbic dopamine (DA) system results in impaired maternal responding in postpartum female rats. However, whether activation of the mesolimbic DA system is capable of promoting maternal behavior has not been investigated. This study examined whether increasing DA activity in various brain regions of pregnancy-terminated, naive female rats would stimulate the onset of maternal behavior. Experiments 1 and 2 examined the effects of microinjection of various doses (0, 0.2, or 0.5 μg/0.5 μl/side) of a D? DA receptor agonist, SKF 38393, or a D? DA receptor agonist, quinpirole, into the nucleus accumbens (NA) on latency to show full maternal behavior, and Experiment 3 determined the effects of SKF 38393 injection into a control site. Finally, because the medial preoptic area (MPOA) is also important for maternal behavior, receives DA input, and expresses DA receptors, the authors examined whether microinjection of SKF 38393 into MPOA was capable of stimulating the onset of maternal behavior. Results indicated that microinjection of SKF 38393 into either the NA or the MPOA facilitates maternal responding in pregnancy-terminated rats. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"A General Behavioral Syndrome Associated with Persistent Failure to Mate in the Male Laboratory Rat": Erratum.

Reports an error in the original article by Jessica J. G. Pottier and Dan Baran (Journal of Comparative and Physiological Psychology) 1973[Jun], 88[3], 499-509). The values given in Table 1 on p. 501 for "Chamber exploration" under "Test 4" and "Test 5" should have been shown as significant at the p 1974-00676-001.) Tested 31 male hooded rats in 7 experiments to determine if those rats which persistently fail to mate (noncopulators) suffer from a specific deficit in sexual behavior or if they show a general behavioral syndrome which distinguishes them from males which mate readily (copulators). Relative to copulators, noncopulators were less active and less responsive to novel stimuli and displayed slower habituation to novelty. Behavioral differences were not correlated with indices of emotionality, state of health, or early rearing conditions. Results are interpreted in terms of a difference in general arousability between copulators and noncopulators. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of progesterone on the reinstatement of cocaine-seeking behavior in female rats.

Estradiol benzoate (EB) facilitates the acquisition and reinstatement of cocaine-seeking behavior when administered to ovariectomized (OVX) rats. In contrast, progesterone (P) decreases acquisition of cocaine self-administration, but the effects of P on the reinstatement of drug seeking are not known. The purpose of the present study was to compare the effects of EB and P on the reinstatement of cocaine-seeking behavior in female rats. Rats received either OVX or sham surgery (SH) and were trained to lever press for intravenous cocaine infusions (0.4 mg/kg) under a fixed ratio 1, 20-s time-out schedule during daily 2-hr sessions. After 14 days of stable responding, saline replaced cocaine, and a 21-day extinction period began. After extinction, rats were separated into 5 treatment groups (OVX+EB, OVX+EB+P, OVX+vehicle [VEH], SH+P, or SH+VEH), and VEH, EB, or EB+P was administered 30 min prior to each session for 5 days. After 3 days of hormone treatment, rats received a saline or cocaine (10 mg/kg) injection, and reinstatement of lever responding was assessed. Reinstatement responding in the OVX+EB group was greater relative to the OVX+EB+P, SH+P, and OVX+VEH groups, which had low levels of cocaine-primed responding. The SH+VEH and OVX+EB groups displayed similar high levels of cocaine-elicited reinstatement. The suppression of cocaine-induced reinstatement following P treatment suggests a role for P in the prevention of relapse to cocaine self-administration in female cocaine users. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An NMDA antagonist impairs copulation and the experience-induced enhancement of male sexual behavior in the rat.

Sexual experience facilitates subsequent male sexual behavior; activation of the N-methyl-D-aspartate (NMDA) glutamate receptor may play a role in this experience-induced enhancement. In this article, the authors report that systemic injections of MK-801, an NMDA receptor antagonist, impaired male sexual behavior in sexually naive and sexually experienced male rats. Furthermore, saline-treated rats that received 7 daily exposures to an inaccessible estrous female instead of sexual experience displayed enhancement of copulation on the following day. Injections of MK-801 before each of these exposures inhibited the experience-induced enhancement on the drug-free test on Day 8. These data suggest that stimulation of NMDA receptors enhances sexual performance immediately and mediates the experience-induced enhancement of subsequent copulatory behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lesions of the medial preoptic area interfere with the display of a conditioned place preference for vaginocervical stimulation in rats.

The present study examined the effect of ibotenic acid lesions of the medial preoptic area (mPOA) on the expression of a conditioned place preference (CPP) for vaginocervical stimulation. Rats with bilateral lesions of the mPOA failed to display the CPP for vaginocervical stimulation shown by rats with sham or incomplete lesions. These findings provide additional support for the role of the mPOA in the neural circuitry underlying the reinforcing effects of female sexual behavior and raise the possibility that the altered pattern of approach and withdrawal behavior observed following lesions of the mPOA may be attributable in part to a diminution of the reinforcing effects of vaginocervical stimulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Predation and Feeding: Comparisons of Feeding Behavior of Killer and Nonkiller Rats": Erratum.

Reports an error in the original article by Luci Paul and Israel Posner (Journal of Comparative and Physiological Psychology, 1973[Aug], 84[2], 258-264). The reference at the top of column 2 on p. 264 should read as follows: KARLI, P. The Norway rat's killing response to the white mouse: An experimental analysis. Behaviour, 1956, 10, 81-103. (The following abstract of this article originally appeared in record 1974-08844-001.) Studied feeding behavior of 34 killer and 34 nonkiller male Long-Evans rats when (a) hungry, (b) with food available, and (c) with prey and other food of high and low palatability. 3 experiments showed that the act of killing did not potentiate feeding but killers were more responsive to dead prey as food than were nonkillers. Results of this and previous studies suggest that the relationship between attack and feeding is not important to the maintenance of killing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Naloxone blocks place preference conditioning after paced mating in female rats.

Sexual behavior in male rats induces a positive affect as evaluated by conditioned place preference (CPP). In addition, when females control or "pace" the rate of sexual interaction, a clear CPP is also observed. The reward state induced by mating in male rats is blocked by the injection of the opioid antagonist naloxone. In the present experiment, a dose of 4 mg/kg of naloxone completely blocked the CPP induced in females by paced mating. It appears that a common opioid system is involved in the positive affect induced by sexual behavior in both male and female rats. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dopamine D1 and D2 Receptor Antagonism in the Preoptic Area Produces Different Effects on Maternal Behavior in Lactating Rats.

The preoptic area (POA) is critical for maternal behavior in rats but little is known about what neurotransmitters released here influence maternal responding. POA infusion of 10 μg (but not 2 μg) of the dopamine D1 receptor antagonist SCH-23390 greatly impaired retrieval and licking of pups but not other maternal or nonmaternal behaviors in lactating rats. In contrast, POA infusion of 10 μg (but not 2 μg) of the D2 receptor antagonist raclopride facilitated nursing but did not affect oral maternal behaviors. SCH-23390 in the medial hypothalamus tended to impair licking but not retrieval. Raclopride in the medial hypothalamus had no effects. Therefore, D1 and D2 receptor activity, particularly in the POA, is important for regulating different maternal behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Activation of POMC neurons during general arousal but not sexual behavior in male rats.

Exogenous opioids influence male rat sexual behavior, suggesting that endogenous opioid peptides are released during mating. Supporting this hypothesis, the authors recently showed that mating induced activation of mu opioid receptors. However, it is unknown which ligand(s) is acting on these receptors during mating. The current set of experiments tested the hypothesis that beta-endorphin-producing neurons, that is, proopiomelanocortin (POMC) neurons, are activated during sexual behavior. Mating-induced activation of POMC neurons was investigated during either the dark phase or the light phase, following different components of male rat sexual behavior or following control manipulations that resulted in general arousal. Results show activation of POMC neurons in the mediobasal hypothalamus following general arousal but not specifically related to sexual behavior per se. In addition, mating did not activate the subpopulation of POMC neurons that project to the medial preoptic nucleus. These results suggest that it is unlikely that POMC neurons contribute to the action of endogenous opioids in the brain area during sexual behavior but instead may contribute to the change in arousal state essential for the expression of sexual behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of alcohol and alcohol expectancies on male perception of female sexual arousal in a date rape analog.

The impact of alcohol and alcohol expectancies on men's perception of female sexual arousal and men's ability to discriminate accurately female sexual intentions in a dating situation was examined. In a 2 (alcohol)?×?2 (expectancy) balanced placebo design, men were exposed to an audiotape of a date rape and asked to signal when the man should stop making sexual advances. On 4 occasions during the vignette, participants rated how sexually aroused the woman on the tape was at that moment. Relative to controls, participants who consumed alcohol or expected to consume alcohol took significantly longer to identify the inappropriateness of the man's sexual behavior toward his date. Similarly, alcohol participants also rated the woman's sexual arousal level significantly higher at the first 2 refusals. Implications of the results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Women's history of sexual abuse, their sexuality, and sexual self-schemas.

In this study, the authors assessed 48 female survivors of child sexual abuse (CSA) and 71 female control participants using measures of adult sexual function, psychological function (i.e., depression and anxiety), and sexual self-schemas. The primary purpose of this study was to examine whether differences existed between women with and without a history of CSA in the way that they viewed themselves as a sexual person and, if so, whether such differences mediated the link between early unwanted sexual experiences and later adult sexuality. CSA survivors were found to view themselves as less romantic and passionate than women who were not abused. In particular, CSA survivors showed an inverse relationship between romantic/passionate sexual self-schemas and negative sexual affect during sexual arousal. The relationship between CSA and negative sexual affect was independent from symptoms of depression and anxiety, suggesting that the impact of CSA on sexual self-schemas may be independent from the impact that the abuse may have in other areas of the survivor's life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Harmful effects of posttermination sexual romantic relationships between therapists and their former clients": Erratum.

Reports an error in "Harmful effects of posttermination sexual and romantic relationships between therapists and their former clients" by Laura S. Brown (Psychotherapy: Theory, Research, Practice, Training, 1988[Sum], Vol 25[2], 249-255). Reference was made to the Minnesota law regarding reporting of "any sexual or romantic relationship in which the parties were once therapist and client" (p. 250). Upon further review by the author, it was determined that the law is more complicated than conveyed in the article. A detailed explanation of the law is provided in the erratum, although legal counsel is suggested for further interpretation. (The following abstract of the original article appeared in record 1989-02991-001.) Examines anecdotal evidence regarding the harmful effects of posttermination sexual or romantic relationships between therapists and clients, focusing on relationships between female therapists and former clients who are also women. The question of equality of power between therapists and former clients is addressed. The impact of these relationships on the community in which they occur is considered. It is concluded that posttermination relationships between therapists and clients have the potential to do as much harm as relationships initiated during therapy and that such relationships should be defined as unethical. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dopamine release in the medial preoptic area is related to hormonal action and sexual motivation.

To help elucidate how general the role of dopamine (DA) release in the medial preoptic area (mPOA) is for the activation of male sexual behavior in vertebrates, we recently developed an in vivo microdialysis procedure in the mPOA of Japanese quail. Using these techniques in the present experiment, the temporal pattern of DA release in relation to the precopulatory exposure to a female and to the expression of both appetitive and consummatory aspects of male sexual behavior was investigated. Extracellular samples from the mPOA of adult sexually experienced male quail were collected every 6 min before, while viewing, while in physical contact with, and after exposure to a female. In the absence of a precopulatory rise in DA, males failed to copulate when the barrier separating them from the female was removed. In contrast, males that showed a substantial increase in mPOA DA during precopulatory interactions behind the barrier, copulated with females after its removal. However, there was no difference in DA during periods when the quail were copulating as compared to when the female was present but the males were not copulating. In addition, we show that precopulatory DA predicts future DA levels and copulatory behavior frequency. Furthermore, the size of the cloacal gland, an accurate indicator of testosterone action, is positively correlated with precopulatory DA. Taken together, these results provide further support for the hypothesis that DA action in the mPOA is specifically linked to sexual motivation as compared to copulatory behavior per se. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of D1 or D2 dopamine receptor antagonism in the medial preoptic area, ventral pallidum, or nucleus accumbens on the maternal retrieval response and other aspects of maternal behavior in rats.

The medial preoptic area (MPOA), ventral pallidum (VP), and nucleus accumbens (NA) receive dopaminergic afferents and are involved in maternal behavior. Experiments investigated whether dopamine (DA) receptor antagonism in NA disrupts maternal behavior, determined the type of DA receptor involved, and investigated the involvement of drug spread to VP or MPOA. Injection of SCH 23390 (D1 DA receptor antagonist) into NA of postpartum rats disrupted retrieving at dosage levels that were ineffective when injected into MPOA or VP. Motor impairment was not the cause of the deficit. Injection of eticlopride (D2 DA receptor antagonist) into NA or VP was without effect. Results emphasize the importance of DA action on D1 receptors in NA for retrieval behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Erratum to Stricker.

Reports an error in the article "The The Renin-Angiotensin System and Thirst: A Reevaluation. II. Drinking Elicited in Rats by Caval Ligation or Isoproterenol" by Edward M. Stricker (Journal of Comparative and Physiological Psychology, 1977, Vol. 91, No. 6, pp. 1220-1231), one line was printed incorrectly. On page 1228, the third line in the left-hand column reads "protin after 2 U/100 g hog renin"; the entire first sentence should read as follows: Three other nephrectomized rats were anesthetized 50 min after .33 mg/kg isoproterenol, 5 min after 2 U/100 g hog renin had been given. (The following abstract originally appeared in record 2005-09077-001) Ligation of the inferior vena cava and administration of isoproterenol have been shown to stimulate renin secretion and to augment water intake in rats. However, the present experiments suggested that the plasma renin activities produced by these treatments do not account for more than 20% of the observed drinking behavior. Direct measurements of arterial blood pressure further indicated that nephrectomized rats go into hypotensive shock after caval ligation or isoproterenol treatment. Drinking was elicited in these hypotensive animals by systemic injection of hypertonic NaCl solution, renin, or Pitressin, or by intracranial injection of angiotensin, but in each case a rapid increase in blood pressure also was observed. Thus, it appears that nephrectomy reduces water intake in these animals by undermining their general capacity to behave rather than by removing a specific dipsogenic stimulus. These and other results suggested that drinking elicited in rats by caval ligation or isoproterenol is not mediated by the renin-angiotensin system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning about sex: Conditioning of partner preference: Theoretical comment on Coria-Avila et al. (2005).

Sexual partner preference in female rats has been difficult to establish experimentally because the vaginocervical stimulation the female receives during the preference test can be rewarding or aversive depending on the context. G. A. Coria-Avila, A. J. Ouimet, P. Pacheco, J. Manzo, and J. G. Pfaus (2005) (see record 2005-06959-008) reported that female rats can be conditioned to show partner preference for a male that is scented with a sexually neutral odor if they are mated repeatedly with that male in a paced mating test. These results suggest that establishment of a partner preference depends on rewarding characteristics of the vaginocervical stimulation the female receives during an initial mating and that selection of a sexual partner can be determined by olfactory stimuli associated with that stimulation. These results are discussed within the context of the appetitive-consummatory construct of sexual behavior and the evolutionary significance of conditioned partner preference. (PsycINFO Database Record (c) 2010 APA, all rights reserved)