Papers by Catherine Ulibarri

Life Sciences, Oct 26, 2006
The purpose of this study was to determine whether testosterone (T) concurrently modulates reprod... more The purpose of this study was to determine whether testosterone (T) concurrently modulates reproductive and nociceptive systems in the adult male. Male Sprague-Dawley rats were orchidectomized, and then 28 days later implanted with capsules containing T or nothing (blanks). After 2, 7, 14 or 28 days' exposure to T-filled or blank capsules, rats were tested for male sexual and nociceptive behaviors in a counter-balanced design. As the duration of T exposure lengthened, the percentage of rats showing male sexual behaviors and the weights of steroid-sensitive organs systematically increased, and latencies to show sexual behaviors decreased. T treatment did not affect basal nociception on either the hotplate or tail withdrawal tests, but significantly increased morphine's antinociceptive potency on the tail withdrawal testhowever, this effect was small, and independent of duration of T exposure. Thus, T treatment that altered male sexual behavior and reproductive physiology in a systematic, duration-dependent manner did not similarly alter basal nociception or morphine antinociception. These findings suggest that in adult male rats, although T may modulate both male sexual behaviors and opioid antinociceptive sensitivity, these T effects do not occur in concert.
Journal of General Virology, Sep 1, 1999
1993). Thrombotic thrombocytopenic purpura associated with human immunodeficiency virus infection... more 1993). Thrombotic thrombocytopenic purpura associated with human immunodeficiency virus infection : demonstration of p24 antigen in endothelial cells.

Journal of Neurobiology, Jul 1, 1990
The neuropeptide cholecystokinin (CCK) inhibits lordosis behavior when infused into the ventromed... more The neuropeptide cholecystokinin (CCK) inhibits lordosis behavior when infused into the ventromedial nucleus of the hypothalamus (VMN) of female rats and has no effect when infused into the VMN of male rats. To test whether this sex difference develops under the control of perinatal steroids, male rats were castrated or given sham surgeries within 3 h of birth and female rats were injected with either 0 or 100 micrograms testosterone propionate on postnatal day 5. As adults, these rats were castrated as necessary, implanted with unilateral cannulae directed at the VMN, and tested for their ability to display female sexual behavior and to respond to CCK. Neonatal castration of males prevented defeminization of this response. When treated with 5 micrograms estradiol benzoate (EB), neonatally castrated males showed both lordosis behavior and a profound inhibition of that behavior after infusions of CCK. Neonatally castrated males did not display lordosis behavior when treated with 2 micrograms EB. Control males showed no lordosis behavior and, therefore, no response to CCK. Both doses of EB induced lordosis behavior in neonatally androgenized females. Significantly, these neonatally androgenized females were less responsive to CCK's inhibition of lordosis and were also anovulatory. These results imply that androgens alter the development of CCK responsive circuits as well as defeminize cyclic gonadotropin release. Levels of 125I-sCCK-8 binding in the VMN were correlated closely with an individual's ability to respond to sCCK-8. In summary, the inhibition of female sexual behavior caused by exogenously administered CCK in normal adult female rats appears to be controlled at least partially by levels of CCK receptors in the VMN and to differentiate under the control of perinatally present testosterone.

The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology, 2003
The spinal nucleus of the bulbocavernosus (SNB) of Mongolian gerbils (Meriones unguiculatus) beco... more The spinal nucleus of the bulbocavernosus (SNB) of Mongolian gerbils (Meriones unguiculatus) becomes sexually dimorphic during postnatal life, rather than prenatally as in rats. We therefore examined the early postnatal ontogeny of Mongolian gerbils, focusing on growth, serum testosterone (T) levels, and the sexually dimorphic perineal musculature innervated by the SNB. Serum T levels were higher in males than in females from birth through adulthood, with several early postnatal peaks and a large increase in T occurring during puberty in males. The SNB target muscles-the bulbocavernosus (BC) and levator ani (LA)-were present in both sexes on postnatal day 1 (PND1). Cross-sectional areas of BC fibers in males increased with age, and concurrently the myofibers of the BC became more fully developed and organized. In PND10 female pups, the BC muscle was virtually absent, while the LA muscle remained (although it was reduced in size). Postnatal treatment of female gerbils with androgen c...
The Journal of general virology, 1999
Equine infectious anaemia virus (EIAV) infection of horses is characterized clinically by recurre... more Equine infectious anaemia virus (EIAV) infection of horses is characterized clinically by recurrent episodes of fever, thrombocytopenia and anaemia. In vivo, the only site of virus replication that has been previously demonstrated for EIAV is the tissue macrophage. In this study, in situ hybridization for EIAV was combined with immunohistochemistry for cell-type-specific markers to identify infected endothelial cells. EIAV-infected endothelial cells and macrophages were detected in horses infected with either virulent wild-type or with weakly virulent tissue culture-adapted strains of EIAV. The role of endothelial cell infection in the pathogenesis of EIAV remains undefined, but could contribute to the development of thrombocytopenia. However, endothelial cell infection does not appear to be a determinant of virulence for EIAV.

Journal of virology, 1998
The equine infectious anemia virus (EIAV) often results in lifelong subclinical infection followi... more The equine infectious anemia virus (EIAV) often results in lifelong subclinical infection following early episodes of clinical disease. To identify the cellular reservoirs of EIAV during subclinical infection, horses were infected with EIAV and allowed to develop subclinical infections. Horses with acute disease served as a basis for comparison. The tissue distribution, replication status, location of infected cells, and viral load were characterized by PCR for proviral DNA and reverse transcriptase PCR for viral RNA, in situ hybridization, and in situ PCR. Proviral DNA was widespread in tissues regardless of disease status. Viral gag and env RNAs were also detected in tissues of all horses regardless of disease status. Plasma viral RNA (viremia) could be detected in some, but not all, horses with subclinical infections. In situ assays determined that a primary cellular reservoir and site of viral replication during subclinical infection is the macrophage. During subclinical infecti...

Behavioral and neural biology, 1988
Gerbils display a sexually dimorphic scent marking behavior that responds to testosterone (T) in ... more Gerbils display a sexually dimorphic scent marking behavior that responds to testosterone (T) in adulthood and develops under the influence of testosterone perinatally. A complex of cell groups between the preoptic area and anterior hypothalamus of the gerbil brain is also sexually dimorphic and responsive to testosterone. One of these cell groups, the sexually dimorphic area pars compacta (SDApc), usually exists only in males. Even when given testosterone, adult female gerbils rarely have an SDApc. To determine if the SDApc develops under the influence of testosterone, male gerbils were castrated or given sham operations on the day they were born or 1 day later, or were not manipulated. Female gerbils were injected subcutaneously with 0, 50, or 100 micrograms testosterone propionate (TP) on the day after birth. When given ovarian transplants as adults, neonatally castrated males scent marked at low levels typical of females. Neonatally androgenized females given testosterone as adu...

Life Sciences, 2006
The purpose of this study was to determine whether testosterone (T) concurrently modulates reprod... more The purpose of this study was to determine whether testosterone (T) concurrently modulates reproductive and nociceptive systems in the adult male. Male Sprague-Dawley rats were orchidectomized, and then 28 days later implanted with capsules containing T or nothing (blanks). After 2, 7, 14 or 28 days' exposure to T-filled or blank capsules, rats were tested for male sexual and nociceptive behaviors in a counter-balanced design. As the duration of T exposure lengthened, the percentage of rats showing male sexual behaviors and the weights of steroid-sensitive organs systematically increased, and latencies to show sexual behaviors decreased. T treatment did not affect basal nociception on either the hotplate or tail withdrawal tests, but significantly increased morphine's antinociceptive potency on the tail withdrawal testhowever, this effect was small, and independent of duration of T exposure. Thus, T treatment that altered male sexual behavior and reproductive physiology in a systematic, duration-dependent manner did not similarly alter basal nociception or morphine antinociception. These findings suggest that in adult male rats, although T may modulate both male sexual behaviors and opioid antinociceptive sensitivity, these T effects do not occur in concert.

Brain Research - BRAIN RES, 1994
Calcitonin gene-related peptide (CGRP) is found in motoneurons of the mammalian spinal cord, incl... more Calcitonin gene-related peptide (CGRP) is found in motoneurons of the mammalian spinal cord, including motoneurons of the androgen-dependent spinal nucleus of the bulbocavernosus (SNB) of the mouse. Motoneurons of the SNB innervate the bulbocavernosus (BC), a striated muscle involved in penile reflexes. CGRP is thought to be a trophic factor produced by motoneurons to regulate the expression of the acetylcholine receptor at the neuromuscular junction. In rats, the number of SNB motoneurons containing CGRP is increased by gonadal steroids. This regulation appears to rely on an activity-dependent factor produced by the BC muscle. The purpose of the present study was to examine, using immunohistochemistry, the steroid dependence of CGRP in the SNB of male house mice. Genotypic differences in the steroid regulation of CGRP immunoreactivity were examined in three strains of mice that differ in their behavioral sensitivity to castration. The results demonstrate that castration reduces the number of CGRP-positive SNB motoneurons in mice. The magnitude of the change in CGRP in response to castration and the length of time required following castration to alter CGRP were dependent on genotype. Interestingly, the effect of castration in mice, to reduce the number of CGRP-immunoreactive SNB motoneurons, is opposite in direction from the increase in CGRP SNB motoneurons observed in rats observed following castration. These experiments suggest that androgens may alter neuromuscular junction function of mouse SNB by regulating the production of CGRP in a species-specific, genotypically dependent fashion.
Toxicology, 1996
... Author Contact Information , James R. Willis b , Thomas C. Nowatka a , Catherine Ulibarri a ,... more ... Author Contact Information , James R. Willis b , Thomas C. Nowatka a , Catherine Ulibarri a , Ronald E. See b and Hal H. Westberg c. a Program in Neuroscience, Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Washington State University ...

Synapse, 1995
Recent evidence implicates a crucial role for the ventral tegmental area (VTA) in the initiation ... more Recent evidence implicates a crucial role for the ventral tegmental area (VTA) in the initiation of behavioral sensitization produced by repeated psychostimulant exposure, while changes in the nucleus accumbens (NAcc) are not critical during the initiation stage. We investigated whether the development of behavioral sensitization to repeated daily cocaine could be prevented by daily administration of the protein synthesis inhibitor, anisomycin, delivered onto VTA neurons. Rats were given five daily treatments as follows: obturators containing crystalline anisomycin or no compound (sham) were placed directly into the VTA 15 min prior to a saline (1 ml/kg, i.p.) or cocaine (15 mg/kg, i.p.) injection. After withdrawal for 8-9 days, the locomotor response to the same dose of saline or cocaine was monitored. No differences in the locomotor response to an acute saline challenge were found across the four groups. Animals given sham treatments in the VTA and daily cocaine demonstrated a significant augmentation in the locomotor response to a cocaine challenge compared to saline controls. Anisomycin treatments alone produced no effects on acute cocaine-induced locomotion. Further, a cocaine challenge in animals receiving daily anisomycin and cocaine elicited a non-augmented response similar to that of saline controls. Thus, the sensitized locomotor response to a cocaine challenge in daily cocaine pretreated animals was completely blocked by daily anisomycin treatment in the VTA. When daily anisomycin was administered into the NAcc along with daily cocaine, no blockade of behavioral sensitization was observed. These results provide support for a critical role of long-term changes in gene expression in the vicinity of VTA neurons mediating the development of sensitization to psychostimulants.

Psychopharmacology, 1996
The role of corticosterone in the initiation and expression phases of sensitization to cocaine wa... more The role of corticosterone in the initiation and expression phases of sensitization to cocaine was examined. To determine the effect of corticosterone on the initiation of sensitization, male Sprague-Dawley rats were given a sham adrenalectomy (ADX), or ADX surgery. Approximately 1 week later, rats were given a cocaine (15 mg/kg, IP) injection on day 1. On days 2-6, rats were given cocaine (30 mg/kg, IP), and the next day, a cocaine challenge (15 mg/kg) was administered (= early withdrawal). Four days later, 50% of the ADX rats were given corticosterone pellets and corticosterone in the evening drinking water to mimic the circadian variation in corticosterone levels. After 1 week, rats were given a final saline challenge followed by a cocaine challenge (15 mg/kg) the next day (= late withdrawal). Locomotor activity was monitored after cocaine treatment on day 1 and after challenge at early and late withdrawal. Sham controls demonstrated a sensitized locomotor response to the cocaine challenge at early withdrawal, with a slight increase in this behavioral sensitization at the late withdrawal time. In contrast, sensitization was not observed in ADX rats after early withdrawal from cocaine, but this attenuation was not permanent, since ADX animals demonstrated control levels of sensitization by the late withdrawal time 12 days later. Animals given corticosterone replacement 1 week prior to the late cocaine challenge also demonstrated a sensitized response similar to control levels. The effect of corticosterone on the expression of sensitization was examined by administering daily cocaine as before followed by surgery a few days later. The treatment groups were sham, ADX and ADX+corticosterone replacement as described. Fourteen days later, a saline injection was given followed by a cocaine challenge the next day. Behavioral sensitization to a cocaine challenge was found in all three treatment groups. These data suggest that adrenal hormones are necessary during the initiation phase of sensitization when observed after early withdrawal (1 day), but not when sensitization is examined at a later withdrawal time (12 days). In addition, corticosterone levels do not significantly affect the expression phase of behavioral sensitization to cocaine.

Psychopharmacology, 1998
We have recently shown that adrenalectomy (ADX) in rats blocks the appearance of cocaine-induced ... more We have recently shown that adrenalectomy (ADX) in rats blocks the appearance of cocaine-induced sensitization when this behavioral response is tested at early withdrawal times (1-2 days), but not after later withdrawal from cocaine (12 days). To determine if a similar phenomenon occurred with stress-induced sensitization, male Sprague-Dawley rats were given a sham ADX, ADX surgery, or ADX plus s.c. implanted corticosterone (CORT) pellets (CORT 12.5% pellets or CORT 50% pellets). A fifth group was given ADX surgery, but CORT 50% pellets were implanted after repeated stress treatment. One week after surgery, each group was divided into two additional groups, naive and stress. Naive animals remained unhandled, while stress rats were given a variety of daily stressors administered twice per day for 6 consecutive days. One day after the last stress, rats were given a saline injection followed by a cocaine injection (15 mg/kg, i.p.) the next day, and locomotor activity was monitored (early withdrawal). Two weeks after the last stress, the locomotor responses to an additional saline and cocaine injection were monitored (late withdrawal). At early withdrawal, no significant sensitization occurred for horizontal activity, but cross-sensitization was demonstrated for vertical activity. At late withdrawal, sham controls showed a stress-induced elevation in horizontal activity, with only a trend toward increased vertical activity. Animals given ADX surgery or ADX and CORT 12.5% pellets did not demonstrate sensitization to repeated stress, while CORT 50% pellets in ADX rats restored the sensitized horizontal response to cocaine challenge at late withdrawal. In contrast, stress-pretreated rats which were given CORT 50% pellets during the 2-week withdrawal period after the stress showed a marked decrease in horizontal activity in response to cocaine challenge at late withdrawal. The results provide evidence for a necessary role for adrenal hormones in long term, but not short-term, stress-induced cross-sensitization. Together with our previous study on the role of CORT in cocaine-induced sensitization, the results indicate that CORT is not the common factor mediating the long-term sensitization to cocaine and stress.

Physiology & Behavior, 1993
Microinjections of sulphated cholecystokinin octapeptide (sCCK-8) into the ventromedial nucleus o... more Microinjections of sulphated cholecystokinin octapeptide (sCCK-8) into the ventromedial nucleus of the hypothalamus inhibit lordosis behavior in receptive female rats. This effect of sCCK-8 seems to differentiate under the control of gonadal steroids shortly after birth. Neonatally castrated males and normal females show similar responses, while androgenized females are less sensitive to sCCK-8. The current study investigated estrogen's role on the differentiation of the response to sCCK-8. On the day of birth male rat pups were castrated, given sham surgeries, or implanted with the antiestrogen tamoxifen or the aromatase inhibitor androst-1, 4, 6-triene-3, 17-dione (ATD). Females were implanted with testosterone propionate or tamoxifen, or given sham surgeries. Implants were removed 10 days later. As adults, rats were tested for female sexual behavior after microinjections of sCCK-8 into the ventromedial nucleus of the hypothalamus. Neonatally castrated males, ATD-treated males, and control females showed profound inhibition of lordosis behavior after sCCK-8. These results suggest that elimination of estrogen postnatally prevents defeminization of the reproductive circuitry that responds to sCCK-8.

Physiology & Behavior, 1987
To test the hypothesis that testosterone (T) sexually differentiates gonadotropin secretion and s... more To test the hypothesis that testosterone (T) sexually differentiates gonadotropin secretion and sexual behavior by inducing synthesis of messenger RNA (mRNA), newborn female rats received intrahypothalamic infusions of saline or cordycepin, an adenosine analogue that preferentially inhibits synthesis of polyadenylated mRNA, an hour before they received T propionate (TP) systemically. As adults, controls were anovulatory and did not become sexually receptive when given estradiol benzoate (EB) and progesterone (P). Cordycepin-treated females obtained lordosis quotients (LQs) three times those of controls and most of them ovulated. Cordycepin also curtailed the defeminizing effects of some doses of moxestrol, an artificial estrogen; thus it does not simply block aromatization. Some groups were retested for lordosis using EB and methysergide to bypass P receptors. Methysergide increased LQs in one group that received moxestrol + cordycepin as neonates and that was moderately responsive to P, but it did not increase sexual receptivity among the saline-treated controls. These data suggest that defeminization of sexual behaviour involves more than defeminization of P receptor synthesis.

Pharmacology Biochemistry and Behavior, 2000
To determine whether sex differences in the effects of mixed-action opioids could be due to diffe... more To determine whether sex differences in the effects of mixed-action opioids could be due to differential activity at mu or kappa receptors, agonist/antagonist properties of nalbuphine, butorphanol and ( À )-pentazocine were compared in male vs. female rats using a diuresis test. In water-loaded rats (2-h test), nalbuphine and ( À )-pentazocine dose-dependently increased urination similarly in both sexes, whereas butorphanol increased urination more in females than in males on a ml/kg basis. The diuretic effects of all three opioids were at least partially blocked by the kappa receptor-selective antagonist nor-binaltorphimine (nor-BNI, 5 mg/kg) in both sexes. Kappa receptor-mediated antagonism of diuresis induced by U69,593 (0.56 mg/kg) was only observed with butorphanol in males. In water-loaded rats (1-h test), nalbuphine did not suppress, and butorphanol and ( À )-pentazocine significantly suppressed urination in males only; all three mixed-action opioids dose-dependently blocked the antidiuretic effect of the selective mu agonist fentanyl (0.056 mg/kg) in both sexes. The ability of nalbuphine and ( À )-pentazocine to block fentanyl-induced antidiuresis was not affected by pretreatment with nor-BNI in either sex. In contrast, the ability of butorphanol to block fentanyl-induced antidiuresis was attenuated by pretreatment with nor-BNI in males but not in females. These results suggest that sex differences in the effects of these mixed-action opioids are primarily due to their greater relative efficacy at the mu receptor in male than in female rats; butorphanol also may have greater efficacy at kappa receptors in females than in males. D (R.M. Craft).

Pain, 2003
The purpose of this study was to examine how gonadal steroid hormones modulate basal nociception ... more The purpose of this study was to examine how gonadal steroid hormones modulate basal nociception and morphine antinociception relative to regulating reproduction in the adult rat. Male and female Sprague-Dawley rats were either gonadectomized (GDX) or sham-gonadectomized (sham); GDX males were implanted subcutaneously with capsules containing testosterone (T), estradiol (E2), dihydrotestosterone (DHT), E2 and DHT, or nothing (0). GDX females received E2, T, or empty (0) capsules immediately after surgery, and vehicle or progesterone (P4) injections at 4-day intervals. Basal nociception and morphine antinociception were tested 28 days after surgery on 50 degrees C and 54 degrees C hotplate tests, and reproductive behavior and physiology were assessed shortly thereafter. There were no significant differences in baseline hotplate latencies among the male treatment groups, but morphine was significantly more potent in sham and GDX+T males than in GDX+0 males. The ability of T to increase morphine's potency was approximated by its major metabolites E2 and DHT, given together but not alone. Baseline hotplate latencies were higher in sham females tested during diestrus than in those tested during estrus. Morphine was significantly more potent in sham females tested during proestrus and diestrus than in those tested during estrus. Baseline hotplate latencies were significantly higher, and morphine was significantly less potent in GDX+E2, GDX+E2/P4 and GDX+T females than in GDX+0 females. All group differences in basal nociception and morphine antinociception observed on the 50 degrees C hotplate test were smaller and generally non-significant on the 54 degrees C hotplate test. Steroid manipulations produced the expected changes in reproductive behaviors and steroid-sensitive organs. These results demonstrate that in adult rats, gonadal steroid manipulations, that are physiologically relevant, modulate (1) basal nociception in females but not males, and (2) morphine's antinociceptive potency in both males and females.

Neuroscience Letters, 2008
Homeostatic plasticity is a powerful cellular mechanism through which neurons adjust intracellula... more Homeostatic plasticity is a powerful cellular mechanism through which neurons adjust intracellular and intercellular resources to stabilize their functional output through the ever-changing environment. Here, we report a novel form of homeostatic plasticity that nucleus accumbens (NAc) neurons use to regain their functionally active state once it is lost. In vivo, NAc neurons periodically alternate between a functionally active upstate and a functionally quiescent downstate. The upstate of NAc neurons is immediately lost following severe environmental changes, such as deep anesthesia and truncation of excitatory synaptic inputs. Using short-term slice cultures, our current study demonstrates that NAc neurons initially lose but gradually recover their upstate-downstate cycling after shifting to the in vitro condition. Furthermore, we show that this homeostatic recovery of the upstate is mediated by increased synchronization of presynaptic activity. Given that being in the upstate is required for in vivo NAc neurons to fire action potentials, the homeostatic recovery of upstate may underlie an important cellular mechanism for NAc neurons to maintain their functional output against severe environmental fluctuations.

Muscle & Nerve, 1996
Previous studies have reported that motoneurons from the sixth spinal nerve (C6) innervate the ma... more Previous studies have reported that motoneurons from the sixth spinal nerve (C6) innervate the majority of muscle fibers in the rat serratus anterior (SA) muscle. The seventh spinal nerve (C7) innervates a limited number of SA fibers, increasing caudally. This topographic map is partially reestablished following denervation. In the present study, muscle fibers of the SA were stained with monoclonal antibodies for the muscle-specific fast myosin heavy chain (F-MHC) and slow myosin heavy chain (S-MHC) proteins. We found that the majority of fibers in the SA muscle stained for F-MHC antibody, and the percentage of muscle fibers staining for S-MHC antibody increased caudally. When newborn SA muscles were denervated and then reinnervated by the entire long thoracic (LT) nerve or only the C6 branch to the LT nerve, the reinnervated muscle had the normal proportion of muscle fibers expressing S-MHC protein. However, if the LT nerve was crushed and only C7 motoneurons allowed to reinnervate the SA muscle, a greater percentage of muscle fibers stained for S-MHC antibody than normal. We conclude that there is a correlation between muscle fiber type and innervation topography in the SA muscle of the rat.
Journal of the American Veterinary Medical Association, 2004
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Papers by Catherine Ulibarri