Lynda Uphouse

• Texas Woman's University

These studies were designed to develop a paradigm for the detection of antidepressant-induced sexual dysfunction in female rats. Ovariectomized, Fischer rats were conditioned to nose poke to open a guillotine door to gain access to a sexually active male. To develop the procedure, we examined the acquisition and stability of the response with a 15-...

The following experiment was designed to test two specific questions: (1) Does the antiprogestin, RU486, reduce emergence of lordosis behavior and/or proceptivity in rats given repeated treatment with 10μg estradiol benzoate (EB) and/or a single high dose (40μg) of EB? (2) Does RU486 accentuate the effects of a 5min restraint experience on sexual b...

Regularly cycling Fischer female rats were treated with either a low (5mg/kg) or high (5mg/RAT; approximately 30mg/kg) dose of the antiprogestin, RU486, before the morning of proestrus or on the morning of proestrus. The emergence of sexual behavior after treatment with RU486 was examined in a mating test with a sexually active male rat. Lordosis b...

A brief restraint experience reduces lordosis behavior in ovariectomized females that have been hormonally primed with estradiol benzoate. The addition of progesterone to the priming prevents the lordosis inhibition. Based on prior studies with an inhibitor of progesterone metabolism, we have implicated the intracellular progesterone receptor, rath...

In this review, first a historical perspective of serotonin's (5-HT) involvement in female sexual behavior is presented. Then an overview of studies implicating 5-HT is presented. The effect of drugs that increase or decrease CNS levels of 5-HT is reviewed. Evidence is presented that drugs which increase 5-HT have negative effects on female sexual...

These experiments were designed to determine if prior sexual experience reduced the negative effect of mild stress on female sexual behavior. In the first experiment, ovariectomized rats were hormonally primed with estradiol benzoate and progesterone for 3 consecutive weeks during which they received 6 mating experiences in a male's home cage or re...

These experiments were designed to test the hypothesis that a progesterone receptor antagonist would block progesterone's ability to reduce the negative effects of a 5min restraint on female rat sexual behavior. Ovariectomized Fisher rats were injected with 10μg estradiol benzoate. Two days later, rats were injected subcutaneously (sc) with the pro...

Introduction. The selective serotonin reuptake inhibitor (SSRI), fluoxetine, leads to sexual dysfunction in a substantial proportion of women. In studies with the Fischer inbred rat, the 5-HT1A receptor has been implicated in this sexual dysfunction. Whether this association with 5-HT1A receptors holds for other rat strains is not known. Aim. The e...

Treatment with selective serotonin reuptake inhibitors, such as fluoxetine, produces sexual side effects with low sexual desire being the most prevalent effect in females. In few studies have preclinical models for such antidepressant-induced sexual dysfunction been fruitful. In the current manuscript, the effects of fluoxetine on multiple measures...

Successful reproduction in mammals, as in other vertebrates, requires coordination among behavioral and physiological processes so that the act of mating occurs coincident with physiological readiness to produce offspring. In the male, successful reproduction requires the maintenance of spermatogenesis and appropriate mating activity. In the female...

Ovariectomized rats, hormonally primed with 10 μg estradiol benzoate and 500 μg progesterone are resistant to the lordosis-inhibiting effects of a 5 min restraint experience. However, modulation of the serotonergic (5-HT) system alters this resistance to stress. In the following experiment, ovariectomized Fischer inbred rats were hormonally primed...

When ovariectomized Fischer female rats are hormonally primed with 10 μg estradiol benzoate, a 5 min restraint experience rapidly inhibits lordosis behavior. Addition of progesterone to the hormonal priming prevents this restraint-induced inhibition. In prior work, we reported evidence that progesterone receptors (PR) may contribute to this protect...

Progestins and antiprogestins are widely used therapeutic agents in humans. In many cases, these are indicated for the treatment of reproductive activities. However, progesterone has widespread physiological effects including a reduction of the response to stress. We have reported that 5 min of restraint reduced lordosis behavior of ovariectomized...

Ovariectomized, Fischer rats were hormonally primed with 10 μg estradiol benzoate and 50 μg progesterone or were treated with the sesame seed oil vehicle. Food intake was measured 2 h and 24 h after treatment with 0.25 mg/kg of the 5-HT(1A) receptor agonist, (±)-8-hydroxy 2-(di-n-propylamino) tetralin (8-OH-DPAT), 5 mg/kg of the selective serotonin...

Serotonin's (5-HT) classical role in regulation of sexual behavior is to inhibit copulation. However, the neurotransmitter exerts a more complex influence on the behavior dependent on the particular aspect of the behavior examined. In this chapter, the historical basis for consideration of 5-HT as a major player in sexual behavior is discussed. Cur...

Ovariectomized Fischer inbred rats were hormonally primed with 10μg estradiol benzoate and sesame seed oil (EO rats) or with estradiol benzoate and 500μg progesterone (EP rats). Four to six hours after progesterone or oil, rats were pretested for sexual behavior and then infused bilaterally into the ventromedial nucleus of the hypothalamus with 0,...

The selective serotonin reuptake inhibitor (SSRI), fluoxetine (Prozac(R)), is an effective antidepressant that is also prescribed for other disorders (e.g. anorexia, bulimia, and premenstrual dysphoria) that are prevalent in females. However, fluoxetine also produces sexual side effects that may lead patients to discontinue treatment. The current s...

In an earlier study, we reported that daily fluoxetine treatment (10 mg/kg/day) rapidly disrupted estrous cyclicity and sexual receptivity in adult, regularly cycling Fischer rats. The current study was designed to investigate if comparable fluoxetine treatment would similarly affect intact, regularly cycling Sprague Dawley rats. In the first exper...

Ovariectomized rats were hormonally primed with 10 microg estradiol benzoate or with estradiol benzoate plus 500 microg progesterone. Rats received a bilateral infusion with 200 ng of the 5-HT(1B/1D) receptor antagonist, N-[4-methoxy-3-(4-methyl-1-piperazinyl)phenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)-1-1'-biphenyl-4-carboxamide hydrochlo...

The partner preference paradigm was used to test the hypothesis that mild restraint reduced sexual motivation of female rats. Ovariectomized rats were primed with 10 µg estradiol benzoate or estradiol benzoate and 500 µg progesterone. Additional rats were injected with sesame seed oil. These three groups of rats (oil–oil, estradiol benzoate–oil, or...

Fluoxetine (Prozac) produces sexual dysfunction in a substantial number of patients. In the few animal studies designed to address this sexual dysfunction in females, data have been inconsistent. Some investigators report that the drug disrupts sexual behavior without affecting the estrous cycle while we have reported robust effects of fluoxetine o...

These experiments were designed to evaluate the hypothesis that fluoxetine-induced sexual dysfunction in female rats derived from disruption of neuroendocrine events that normally facilitate sexual behavior. If so, exogenous hormonal priming to ovariectomized rats should eliminate fluoxetine's effect. Ovariectomized rats were subchronically treated...

Ovariectomized Fischer (CDF-344) rats, with bilateral cannulae in the mediobasal hypothalamus (MBH) near the ventromedial nucleus of the hypothalamus (VMN), were used to test the hypothesis that serotonin receptors in the VMN contribute to the lordosis-inhibiting effects of mild restraint. Rats were hormonally primed with 10 microg estradiol benzoa...

Ovariectomized rats with bilateral cannulae near the ventromedial nucleus of the hypothalamus were hormonally primed with 10 microg estradiol benzoate and 500 microg progesterone. Sexually receptive females were infused bilaterally with 200 ng of the 5-HT(1A) receptor agonist, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), or with a combinati...

Ovariectomized female rats were used to test the possibility that the 5-HT(1A) receptor agonist, 8-hydroxy-2-(di-N-propylamino) tetralin (8-OH-DPAT), inhibits cyclic AMP (cAMP) accumulation in the mediobasal hypothalamus. Tissue slices were incubated with forskolin or with the beta-adrenergic receptor agonist, isoproterenol, to stimulate accumulati...

Adult, regularly cycling female Fischer rats were injected daily with 10 mg/kg fluoxetine for 12-23 days. In the first experiment, body weight and vaginal smears were monitored daily. Fluoxetine treatment reduced body weight within the first 24 h of treatment. Fluoxetine treatment also elongated the estrous cycle, reduced blood levels of progestero...

The effect of 5 min of restraint on the time sexually-receptive females spend in the compartment of a sexually active male was examined. Ovariectomized females, hormonally primed with 10 microg estradiol benzoate and 500 microg progesterone (EP) or primed only with estradiol benzoate (EO) were used. After the restraint or home-cage experience, fema...

Both serotonin (5-HT) and gamma-aminobutyric acid (GABA) modulate female rat lordosis behavior and appear to interact in their control of the behavior. The current experiments were designed to investigate the interaction between these two neurotransmitters in sexually receptive female rats. Ovariectomized female rats, with bilateral cannulae direct...

Sexually receptive proestrous rats with bilateral cannulae in the ventromedial nucleus of the hypothalamus (VMN) were infused with 200 ng of (+/-)-8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) or with 8-OH-DPAT plus varying concentrations (200 to 2000 ng) of the 5-HT1A receptor antagonist, N-[2[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]N-(2-pyr...

The effects of the 5-HT(2A/2C) receptor antagonist, ketanserin, and the 5-HT(2C) receptor antagonist, SB 206553, on lordosis behavior were investigated in ovariectomized rats hormonally primed with estradiol benzoate (EB) (0.5 or 25 microg) and progesterone (500 microg). Both ketanserin and SB 206553 inhibited lordosis behavior after infusion into...

Ovariectomized rats were hormonally primed with various doses of estradiol benzoate (EB; 0.5-10 microg) in combination with various doses of progesterone (2.5-500 microg) to induce sexual receptivity. Females were then subjected to 5 min restraint and the effect on lordosis behavior was monitored for the next 30 min. Such mild stress has been previ...

The effect of restraint on lordosis behavior was examined in proestrous and ovariectomized, hormone-primed rats. Restraint durations from 5 to 60 min had no effect on lordosis behavior of proestrous rats. There was also no effect of 5 min restraint on lordosis behavior of ovariectomized rats hormonally primed with 10 microg estradiol benzoate and 5...

Ovariectomized, hormone-primed rats were used to test the hypothesis that progesterone treatment attenuated the effects of the 5-HT(1A) receptor agonist, (+/-)-8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), on female rat lordosis behavior. Based upon prior evidence that prepriming with estradiol benzoate (EB) reduced the ability of 8-OH-DPAT t...

The effect of restraint on lordosis behavior was examined in proestrous and ovariectomized, hormone-primed rats. Restraint durations from 5 to 60 min had no effect on lordosis behavior of proestrous rats. There was also no effect of 5 min restraint on lordosis behavior of ovariectomized rats hormonally primed with 10 μg estradiol benzoate and 500 μ...

Fischer and Sprague-Dawley ovariectomized rats were hormonally primed with estradiol benzoate (EB) and progesterone, and the ability of the 5-HT(1A) receptor agonist, (+/-) 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), to inhibit lordosis behavior was examined. Both strains showed rapid inhibition of lordosis behavior following either intrape...

The inhibitory and facilitatory effect of serotonergic (5-HT) receptor agonists and antagonists on the female rat lordosis reflex is reviewed. Emphasis is placed on the role of 5-HT(1A) and 5-HT(2) receptors. The effect of estrogen and progesterone on the lordosis response to 5-HT receptor-selective compounds is reviewed and potential mechanisms fo...

The effects of a soluble derivative of forskolin and of two membrane-permeable analogs of cAMP, dibutyryl cAMP, and 8-bromo-cAMP, on the ability of a serotonin (5-HT)(1A) receptor agonist to inhibit lordosis behavior were examined. Sexually receptive, proestrous rats received a bilateral infusion into the ventromedial nucleus of the hypothalamus (V...

The effects of bilateral VMN infusion with the 5-HT1A receptor agonist, (+/-)-8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 200, 1000, or 2000 ng), on lordosis behavior were examined in hormonally primed ovariectomized rats. When rats were given a single injection with 25 microg estradiol benzoate followed 48 h later with 500 microg progestero...

In vivo microdialysis was used to examine extracellular serotonin (5-HT) in the mediobasal hypothalamus (MBH) of male and female Fischer (CDF-344) rats. Females from the stages of diestrus, proestrus, and estrus were used. Additionally, ovariectomized rats, primed subcutaneously (s.c.) with estradiol benzoate or estradiol benzoate plus progesterone...

Adult, hormone-primed, ovariectomized rats (CDF-344) with bilateral implants within the ventromedial nucleus of the hypothalamus (VMN), were injected with 0.5 microgram estradiol benzoate followed 48 h later with 500 microgram progesterone. This priming produced rats with 2 different levels of sexual receptivity. Rats with a lordosis to mount ratio...

Regularly cycling, proestrous female rats received infusions of 200 ng of the serotonin (5-HT) 1A receptor agonist, (+/-) 8-hydroxy 2-(di-n-propylamino) tetralin-HBr (8-OH-DPAT), or 200 ng 8-OH-DPAT and 1000 or 2000 ng of N-(3-trifluoro-methylphenyl) piperazine hydrochloride (TFMPP) or 2-(1-piperazinyl) quinoline dimaleate (quipazine). Infusions we...

Serotonin (5-HT) receptor interaction in the control of female rat lordosis behavior was examined. Ovariectomized rats, with bilateral implants in the ventromedial nucleus of the hypothalamus (VMN), were hormonally primed with 25 μg estradiol benzoate and 500 μg progesterone. Rats were infused with the 5-HT3 receptor antagonist, 3-tropanyl-indole-3...

The lordosis-inhibiting effects of the 5-HT1A receptor agonist, (+/-)8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), were examined in ovariectomized rats, hormone primed with 2.5, 7.5, or 25 micrograms estradiol benzoate plus 500 micrograms progesterone. 8-OH-DPAT (50, 100 or 200 ng per bilateral site) infused into the ventromedial nucleus of...

Ovariectomized rats were hormonally primed with 0.5 microg estradiol benzoate and 500 microg progesterone to produce two groups of rats differing in their lordosis behavior. Females with a lordosis to mount (L/M) ratio < 0.5 were used to test the hypothesis that 5-HT(2A/2C) receptor agonists could facilitate lordosis behavior. Females with L/M rati...

MASWOOD N., AND L. UPHOUSE. Modulation of the behavioral effects of 8-OH-DPAT by estrogen and DOI. PHARMACOL BIOCHEM BEHAV 58(4) 859–866, 1997.—The effects of female gonadal hormones on 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT)-induced flat body posture, hypothermia, and eating behavior were examined. Ovariectomized rats were injected with...

The effects of prior treatment with 8-OH-DPAT on 8-OH-DPAT-induced eating behavior, hypothermia, flat body posture and forepaw treading were examined in ovariectomized rats. Twenty-four hours after a single pretreatment with 0.25 mg/kg of the drug, the eating behavior and flat body posture induced by 8-OH-DPAT were reduced relative to that seen fol...

Within the ventromedial nucleus of the hypothalamus (VMN), serotonin exerts a dual role in the control of female rat lordosis behavior. Most emphasis has been placed on 5-HT1A and 5-HT2 receptors, which inhibit and facilitate the behavior, respectively. In the current experiment, a potential role for VMN 5-HT3 receptors in the control of lordosis b...

In this manuscript, current knowledge about central nervous system serotonin (5-HT) receptors is discussed with an emphasis toward describing the functional significance of the multiple 5-HT receptors. Five characteristics of 5-HT receptors, which are hypothesized to contribute to this functional significance, are discussed: (a) 5-HT has varying af...

The effects of repeated treatment with estradiol benzoate to ovariectomized rats on the lordosis-inhibiting action of the 5-HT1A agonist, 8-hydroxy-2(di-n-propylamino) tetralin (8-OH-DPAT), were examined. In the first week of hormonal priming, when rats were injected with estradiol benzoate (2.5-50 micrograms) plus 500 micrograms progesterone, all...

In proestrous rats, serotonin 1A (5-HT1A) receptor agonists inhibit lordosis behavior within 5-15 min following infusion into the ventromedial nucleus of the hypothalamus (VMN). In the present report, the lordosis-inhibiting effects of the 5-HT1A agonist [(+/-) 8-hydroxy-2- (di-n-propylamino) tetralin) (8-OH-DPAT] were shown to be attenuated with 5...

The effects of the 5-HT2A/2C antagonists, mianserin and ketanserin, were investigated in proestrous rats and in ovariectomized rats hormonally primed with estradiol benzoate and progesterone. Drugs were administered systemically or by infusion into the vicinity of the ventromedial nucleus of the hypothalamus (VMN). By both routes of administration,...

Sexually receptive proestrous rats were infused bilaterally into the ventromedial nucleus of the hypothalamus (VMN) with 200 ng of 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), 1000 or 2000 ng of 5-methoxy-3-(di-n-propylamino) chroman (5-MEO-DPAC), or 1000 or 2000 ng of serotonin (5-HT) plus or minus the agonist, (2,5-dimethoxy-4-iodophenyl)...

Effects of the 5-HT1A agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 0.04, 0.25, or 1.0 mg/kg), on hypothalamic serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), and their ratio were determined in adult male rats and in diestrous, proestrous, and estrous female rats. Consistent with its action at the somatodendritic 5-HT1A autorec...

Proestrous rats were infused unilaterally into the median raphe nucleus with 200-2,000 ng of the 5-HT1A agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). Inhibition of the lordosis to mount ratio occurred within 15 and 10 min, respectively, following infusion with 1,000 or 2,000 ng of the drug. Infusion of 2,000 ng of the 5-HT2 agonist,...

Sexually receptive, intact, proestrous rats were infused bilaterally into the ventromedial nucleus of the hypothalamus (VMN) with 200 ng of the 5-HT1A agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), with 2000 ng of the 5-HT2/1C agonist, (+/-)-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane HCl (DOI), or with both 8-OH-DPAT and DOI. Alone,...

Ovariectomized rats were treated for consecutive weeks with 25 μg estradiol benzoate followed 48 h later with 500 μg progesterone. Bilateral infusions of 200 ng 8-hydoxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) into the ventromedial nucleus of the hypothalamus (VMN) inhibited female sexual behavior on the first but not the second week of hormone pr...

Sexually receptive, intact, proestrous rats were infused bilaterally into the ventromedial nucleus of the hypothalamus with one of several serotonin (5-HT) agonists and with the endogenous ligand, 5-HT. Serotonin (2000 ng) and the 5-HT1A agonists, 8-hydroxy-2-(di-n-propylamino)tetralin [8-OH-DPAT (200 ng)], 5-methoxy-3-(di-n-propylamino)chroman [5-...

The effects of intracerebral infusions of the 5-HT1A agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), on sexual behaviors of intact, proestrous rats were examined. When administered into either the rostral or the caudal portions of the medial preoptic area (mPOA), bilateral infusions of 200, 500, or 2,000 ng of 8-OH-DPAT reduced lordosi...

Sexually receptive female rats were infused intracranially with 500-2,000 ng 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) into the midbrain central gray (MCG), in the vicinity of the dorsal raphe nucleus (DRN), or directly into the DRN. When cannulae were located within the DRN, there was little evidence of change in lordosis behavior but a d...

Ovariectomized rats were primed with sesame oil or estradiol benzoate followed 48 h later by either sesame oil or progesterone. Four hours later, rats were treated with either saline or 0.25 mg/kg 8-hydroxy-2-9(di-n-propylamino)tetralin (8-OH-DPAT). Rats were allowed to eat for 4 h after this final treatment. Animals in all hormonal conditions show...

Proestrous rats were infused intracerebrally with 50-1000 ng 8-OH-DPAT, 500 or 2000 ng buspirone or 125-500 ng NAN-190. For each drug, bilateral infusions into the mediobasal hypothalamus inhibited female lordosis behavior and proceptivity and initiated resistive behavior. The effects of the drugs were evident within 5-20 min of infusion and genera...

The effects of the chlorinated pesticide chlordecone on food intake, body weight, and water intake were examined in adult male rats. Chlordecone treatment produced a dose dependent suppression of food intake. Loss of body weight accompanied the reduced food intake. However, chlordecone did not suppress water intake. Chlordecone treated animals main...

Intact, adult female rats were injected for 21 days with 10 mg/kg of the tricyclic antidepressant imipramine. During this time, there was almost total suppression of reproductive cyclicity as indicated by the absence of vaginal proestrus and by the absence of sexual receptivity. However, there was no evidence for a permanent disturbance in the fema...

The effects of the 5-HT1A agonist, 8-hydroxy-2-9(di-n-propylamino)tetralin (8-OH-DPAT) on eating behavior and on rectal temperature were examined in adult male rats and in diestrous, proestrous, and estrous female rats. The 5-HT1A agonist produced evidence of hyperphagia at some dose (0.125, 0.25, 0.5 and 1.0 mg/kg) in all groups examined. However,...

The effect of the estrogen-like chlorinated pesticide chlordecone (Kepone) on sexual behavior was examined in proestrous rats following treatment with 25, 50, or 75 mg/kg chlordecone. In most animals, sexual behavior, both receptivity and proceptivity, was reduced within 60 min following the higher dosage of chlordecone. Reduced sexual receptivity...

The effects of the 5-HT1A agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), were examined in intact, proestrous rats. Although this compound has been reported to inhibit sexual receptivity of hormonally primed, ovariectomized rats, this is the first report of its effect in intact females. After intraperitoneal treatment with 8-OH-DPAT (0...

The effects of 25, 50, or 75 mg/kg chlordecone on vaginal and behavioral estrus were examined following treatment of intact rats during estrus, diestrus 1, or diestrus 2. Chlordecone accelerated vaginal estrus, but sexual behavior was eliminated, delayed, or reduced. Chlordecone treatment led to the presence of vaginal estrus within 2 days, but red...

The effects of 25 and 75 mg/kg p,p'-DDT on the CNS serotonergic system were examined in proestrous female rats. Females were treated with p,p'-DDT on the morning of proestrus and were sacrificed that evening. Levels of serotonin (5-HT) and its major metabolite, 5-hydroxyindoleacetic acid (5-HIAA), were examined in cortex, hippocampus, hypothalamus...

The ability of the chlorinated pesticide chlordecone to induce the CNS (hypothalamus and preoptic area) plus pituitary and uterine progesterone receptors was examined in CDF-344 female rats following treatment with 25 micrograms estradiol or with 75 mg/kg chlordecone. In adult ovariectomized rats and in intact immature rats, estradiol increased pro...

The binding of 3H-5-HT to hypothalamic, hippocampal and striatal membranes from female rats was examined. During the day of proestrus, there was a significant increase in binding from morning to evening. The increase reflected changes in both Kc and Bmax. Effects of estradiol were examined in ovariectomized rats, and changes in 3H-5-HT binding resu...

Regularly cycling, adult female rats were treated during diestrus with 10, 25, 33 or 50 mg/kg lindane or with 2.5 mg/kg picrotoxin. The effects of the treatments on estrous cyclicity and on sexual behavior were examined. Doses of lindane greater than or equal to 25 mg/kg significantly increased the length of the vaginal cycle. Sexual receptivity wa...

The in vivo and in vitro effects of the chlorinated pesticide, chlordecone, on the estradiol receptor of adult ovariectomized CDF-344 rats were examined. Chlordecone's competition with [3H]estradiol for binding to the estradiol receptor in vitro was similar whether receptors were derived from neural or uterine tissue. In vivo, chlordecone led to nu...

Sexual behavior of adult, female rats was tested following treatment with o,p'-DDT or with p,p'-DDT during either diestrus or proestrus. Both chlorinated compounds decreased lordosis behavior, but o,p'-DDT did so only after treatment on diestrus. p,p'-DDT in contrast, decreased sexual behavior under all treatment conditions. o,p'-DDT may have alter...

This study concentrates on the role of the serotonin system in mediating the proestrous effects of chlordecone on female rodent sexual behavior. The pesticide was examined within the context of serotonin changes taking place on proestrous. Between morning and evening on the day of proestrus there was an increase in 3H-5-HT binding, an increase in s...

Female rats were injected on the morning of proestrus with 25, 33, 50 or 75 mg/kg lindane or with 1, 2, 2.5 or 3 mg/kg picrotoxin. That evening, females were examined for lordosis behavior with a sexually experienced male. Picrotoxin had no inhibitory effects on lordosis behavior. There was a dose-dependent reduction in sexual receptivity (lordosis...

The chlorinated pesticide, chlordecone, is widely recognized for its production of reproductive deficits. This reproductive sterility has been attributed to chlordecone's apparent "estrogenicity" and its ability to inhibit the release of luteinizing hormone (LH) from the anterior pituitary. However, it was recently noted that the pesticide could al...

The binding of [3H]5-hydroxytryptamine ([3H]5-HT) to cortical membranes was examined in female rats during diestrus, proestrus and estrus. Serotonin binding was lowest during the early afternoon of proestrus and highest during the afternoon of estrus with diestrous values in between. The high estrous values were associated with a significant increa...

The effects of chlordecone on fertility were examined in adult, intact female rats. Rats were treated with 25, 50 or 75 mg/kg chlordecone and initial exposure occurred either on the morning before mating or on the morning after mating. When exposure occurred on the morning of proestrus, mating behavior 8 to 9 hours was significantly reduced by 50 o...

Neonate, female rats pups were injected with varying doses of chlordecone in cotton seed oil or with 1 mg chlordecone in dimethylsulfoxide. The effects of these neonatal treatments on vaginal opening, persistent vaginal estrus and adult sexual behavior were examined. Females treated with chlordecone showed earlier onset of vaginal opening and devel...

The effect of chlordecone on behavioral estrus was examined in adult ovariectomized female rats. Chlordecone has been reported to resemble estrogen in altering pituitary secretions, in producing vaginal cornification, in increasing uterine weight and in competing for binding to the estrogen receptor. In the present study, 10, 25, 50 or 75 mg/kg chl...

Serotonin receptors were examined in various brain regions of female rats 24 hours after treatment with 25, 50 or 75 mg/kg chlordecone. With each dose of chlordecone, there was a significant reduction in the specific binding of 3H-5-HT to striatum. Binding to cortex, hippocampus, hypothalamus, midbrain or brainstem did not systematically vary as a...

The effects of chlordecone on reproductive function was examined in adult females. Chlordecone was shown to mimic estrogen by producing persistent vaginal estrus in ovariectomized and intact females. In ovariectomized females, chlordecone reduced serum levels of luteinizing hormone (LH) and increased prolactin (PRL). In intact females, chlordecone...

The relevance of neurobiology to other scientific disciplines and to sociological studies is described. The emergence of neurobiology as a distinct area of knowledge is a comparatively recent event. The distinctive features of the nervous system and the major regulatory role of such tissue are discussed. The brain's control of endocrine phenomena a...

The purpose of this study was to correlate the chlordecone-elicited tremor activity with alterations of brain neurotransmitters. A single injection of chlordecone (80 mg/kg, ip) significantly increased the brain levels of 5-hydroxyindoleacetic acid (5-HIAA) but did not affect the concentrations of dopamine, dihydroxphenylacetic acid, aspartate, tau...

The effects of chlordecone on vaginal estrus and neuroendocrine responses were examined in adult ovariectomized and intact females. Persistent vaginal estrus was seen in females given 50 mg/kg or more of chlordecone. The development of vaginal estrus was similar to that seen in ovariectomized females after treatment with estrogen. Since chlordecone...

The effects of prior behavioral testing on endocrine function, brain weight, and neurotransmitter receptors were examined. Rats with a history of behavioral testing were significantly different from comparatively naive animals. Prior tested male and females had lower prolactin levels than nontested animals, and serum luteinizing hormone and cortico...

The effect of acute and subchronic acrylamide treatment on levels of dopamine, serotonin, and their metabolites was determined in several brain regions of the rat. Concentrations of several neuropeptides and circulating hormones were also measured. Both a single and repeated doses of acrylamide resulted in elevated levels of 5-hydroxyindolacetic ac...

A procedure based on spectral analysis of whole body movements was developed to quantify chlordecone-induced tremor in rats. Male, Fischer-344 rats were given single or repeated ip doses of chlordecone, and whole body tremor was measured at 2.5-Hz intervals from 2.5 to 20 Hz. The most prevalent frequency and associated magnitude were recorded. Spec...

The roles of estrogen in the regulation of pituitary and brain enkephalin systems were studied. A sex-related difference in the levels of enkephalins was observed in the anterior lobe of rat pituitary. Administration of estradiol to male rats caused a marked reduction in the levels of enkephalins in the anterior lobe. Ovariectomy produced a signifi...

Complications regarding the use of DMSO as a solvent for chlordecone studies are discussed. Data reported here were derived from a study, originally designed to provide further information about the effects of neonatal chlordecone treatment on female reproductive function. Male and female rats were injected at four days of age with water, DMSO, or...

Serum prolactin and corticosterone levels were measured in rats that had been gentled by handling and that had been exposed to 100 mg/kg acrylamide. Handling reduced both corticosterone and prolactin levels. Acrylamide had no effect on corticosterone levels. Prolactin levels were significantly lower in acrylamide-exposed nonhandled animals. These f...

The effects of (1) method of sacrifice, (2) treatment of tissue and membranes, and (3) gavaging on neurotransmitter receptors were assessed. Most variables did not affect binding, but freezing of forebrain tissue decreased protein recovery and therefore estimates of binding sites per brain weight. Serotonin binding was especially sensitive to freez...

Rats were either handled for one week or were left undisturbed in their home cages. Twenty-four hours after exposure to 100 mg/kg acrylamide, rats were sacrificed and spiroperidol binding investigated in the striatum. In handling-gentled rats, spiroperidol binding was reduced by acrylamide. In non-handled animals, no overall drug effects were seen,...

Binding of serotonin to rat brain membranes increased linearly from birth to adulthood, but newborn receptor densities were already 39% of adult levels. These data suggest a postnatal development of serotonin receptors, coincident with synaptic maturation but do not preclude a non-transmitter function for serotonin during early maturation.

Brain, liver, and adrenal weights were measured in rats differentially reared from 28-60 days of age. Relative to the standard colony rats, enriched rats had heavier brains but lighter livers. Relative to the standard animals, impoverished rats had heavier adrenals. These results confirm differential rearing influences on organs other than the brai...