Changes in progressive ratio responding for intravenous cocaine throughout the reproductive process in female rats

Hecht, Gerald S.; Spear, Norman E.; Spear, Linda P.

doi:10.1002/(sici)1098-2302(199909)35:2<136::aid-dev6>3.3.co;2-b

Cited by 25 publications

(37 citation statements)

References 2 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Early postpartum is characterized by very low concentrations of estrogen and high concentrations of progesterone and prolactin; concentrations gradually shift back to the normal cycling state during late postpartum (Grota and Eik-Nes 1967;Smith and Neill 1977;Taya and Greenwald 1982). Although low estrogen concentrations are associated with reduced cocaine self-administration (Roberts et al 1989;Hecht et al 1999) and high progesterone concentrations with attenuated cocaine CPP (Russo et al 2003a(Russo et al , 2008, cocaine CPP remains nearly identical in early and late postpartum, suggesting that cocaine CPP may be relatively insensitive to subtle hormonal changes occurring across the postpartum period. Collectively, however, we believe that the unique endogenous combinations and concentrations of gonadal and lactogenic hormones present across postpartum may establish a prolonged period that subtly alters and increases the incentive value of cocaine.…”

Section: Discussionmentioning

confidence: 99%

“…While cocaine CPP is influenced by sex (Russo et al 2003b;Carroll et al 2004;Jackson et al 2006), estrus cycle stage (Roberts et al 1989;Hecht et al 1999), and exogenous administration of ovarian hormones (Russo et al 2003a(Russo et al , 2008, little research exists on cocaine CPP across the postpartum period, a complex phase characterized by subtle fluctuations in endogenous ovarian hormones and neuroactive peptides and influenced uniquely by biologically relevant stimuli (i.e., pups). The present study constitutes the first systematic examination of cocaine's incentive value across this unique period in the natural lifecycle of the female rat.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Incentive salience of cocaine across the postpartum period of the female rat

et al. 2008

View full text Add to dashboard Cite

Rationale-Objectives-Our prior conditioned place preference (CPP) work demonstrates that late (day16) postpartum female rats consistently prefer cocaine-over pup-associated chambers, whereas far fewer early postpartum (day8) females prefer the cocaine-associated chamber. The present study examines early and late postpartum females' preference for a cocaine-associated chamber when contrasted with a chamber associated with saline (rather than pups).Materials and methods-Postpartum females were tested for conditioned preference for chambers associated with cocaine (10 mg/kg subcutaneous (SC) or 0.5, 5, 10, or 20 mg/kg intraperitoneal (IP) injections) versus saline; preferences of virgin female and male rats for select cocaine stimuli (10mg/kg SC or IP) were also tested. Locomotion was recorded during CPP conditioning and testing.Results-Early and late postpartum females expressed strikingly similar preference for the cocaineassociated chamber across all administration routes and doses. IP cocaine produced an orderly, inverted U-shaped dose-preference curve, with preference peaking at the 5 mg/kg dose (83% of females). While many postpartum females preferred 10mg/kg cocaine administered either SC or IP, both virgin females and males expressed strong aversion to SC cocaine and, while virgin females strongly preferred IP cocaine, males remained relatively indifferent. Across 10mg/kg IP cocaineconditioning sessions, locomotor sensitization occurred exclusively in cocaine-but not salinepreferring postpartum females. Locomotor rate was lower in preferred versus nonpreferred chambers at CPP test.Conclusions-Early and late postpartum females may be equally and uniquely susceptible to sampling and/or abuse of modestly salient doses of cocaine (10mg/kg SC; 5mg/kg IP) compared to virgin females and/or males.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Incentive salience of cocaine across the postpartum period of the female rat

et al. 2008

View full text Add to dashboard Cite

show abstract

“…When tested under a progressive ratio schedule of responding for cocaine, female rats reach a greater ratio of lever presses to infusions of cocaine (ie a higher breaking point) on behavioral estrus, than they do during other phases of the cycle; females also have higher breaking points than male rats (Roberts et al, 1989). In contrast, sucrose self-administration does not vary across the estrous cycle (Hecht et al, 1999). Although estrous/menstrual cycle effects demonstrate the involvement of ovarian hormones, they do not identify which specific ovarian hormones are involved.…”

Section: Introductionmentioning

confidence: 93%

Sex Differences and Hormonal Influences on Acquisition of Cocaine Self-Administration in Rats

Jackson

Robinson

Becker

2005

Neuropsychopharmacol

282

272

View full text Add to dashboard Cite

Men and women differ in their response to cocaine, and a woman's response varies with the menstrual cycle. For example, women have greater subjective responses to cocaine in the follicular phase of the menstrual cycle when estradiol is predominant, than they do during the luteal phase when both estradiol and progesterone are elevated. Similarly, female rats show significantly more cocaine-induced locomotor behavior and cocaine self-administration during behavioral estrus, shortly after estradiol peaks, than during other stages of the cycle, and estradiol administration to ovariectomized (OVX) females enhances the acquisition of cocaine self-administration. The purpose of this study was to expand upon these findings by studying the effects of progesterone administration to females, and estradiol administration to males, on acquisition of cocaine self-administration. We report here that there are both sex differences in and effects of circulating ovarian hormones on acquisition of cocaine self-administration. We demonstrate that although estradiol administration enhances acquisition of cocaine self-administration in OVX female rats, concurrent administration of progesterone with estradiol inhibits this effect of estradiol. In a separate experiment, we demonstrate that estradiol administration does not enhance acquisition of cocaine self-administration in castrated male rats. We conclude that (1) there is a sex difference in the effects of estradiol on cocaine selfadministration: it facilitates acquisition in female, but not male rats; and that (2) in females concurrent progesterone treatment counteracts the facilitory effect of estradiol on cocaine self-administration.

show abstract

“…During the rat estrus phase, when estrogen and progesterone levels begin to decline, rats respond more for infusions of cocaine under a progressive ratio schedule of reinforcement (Hecht et al, 1999;Roberts et al, 1989), while responding maintained by a non-drug reinforcer remains unchanged (Hecht et al, 1999). Ongoing cocaine self-administration becomes highly dysregulated during estrus compared to other phases of the estrous cycle (Lynch et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

Effects of menstrual cycle phase on the reinforcing effects of phencyclidine (PCP) in rhesus monkeys

Newman

Thorne

Batulis

et al. 2006

Pharmacology Biochemistry and Behavior

View full text Add to dashboard Cite

Substantive evidence indicates that there are sex differences in the reinforcing effects of drugs and gonadal steroid hormones, such as estrogen and progesterone, likely contribute to these differences. Among females, subjective effects of drugs differ as a function of menstrual cycle phase. The purpose of the present study was to compare oral self-administration of phencyclidine (PCP) in female rhesus monkeys (Macaca mulatta) across different phases of the menstrual cycle. Since the 28-day menstrual cycle of nonhuman primates is similar to that of humans, this model could provide important evidence supporting the implication that changes in the levels of gonadal hormones across menstrual phases can alter a drug's reinforcing effects. Oral self-administration of several concentrations of PCP (0.125, 0.25, and 0.5 mg/ml) was examined in three sexually mature female monkeys during 3-h experimental sessions. Menstrual cycle phase was determined by onset of menses, and verified by examining vaginal cytology. Overall, PCP self-administration was greater during the luteal phase, which is normally characterized by high levels of progesterone and moderate levels of estrogen, than the follicular phase, when levels of estrogen are increasing and progesterone levels are low. When examined within each phase, numbers of PCP deliveries were highest during the mid-luteal phase, compared to the early and mid-follicular phases. No differences in selfadministration were observed between early and mid-follicular phases, but a significant difference in PCP deliveries was found between mid-and late luteal phases at the lowest concentration of PCP tested. The results from this study suggest that PCP's reinforcing effects in female monkeys differ as a function of menstrual cycle phase.

show abstract

Changes in progressive ratio responding for intravenous cocaine throughout the reproductive process in female rats

Cited by 25 publications

References 2 publications

Incentive salience of cocaine across the postpartum period of the female rat

Incentive salience of cocaine across the postpartum period of the female rat

Sex Differences and Hormonal Influences on Acquisition of Cocaine Self-Administration in Rats

Effects of menstrual cycle phase on the reinforcing effects of phencyclidine (PCP) in rhesus monkeys

Contact Info

Product

Resources

About