Predicting Pharmacist Dispensing Practices and Comfort Related to Pre-exposure Prophylaxis for HIV Prevention (PrEP).

To identify factors associated with pharmacist dispensing practice and comfort counseling patients about pre-exposure prophylaxis for HIV prevention (PrEP). Cross-sectional 2016 census of Indiana managing pharmacists measured PrEP awareness, comfort dispensing and counseling patients. Modified Poisson models with robust error variance estimated relative risks and confidence intervals. 15.8% of 284 pharmacists had dispensed PrEP and 11.6% had consulted about it. Dispensing and comfort counseling were associated with confidence in knowledge about PrEP medication adherence and adverse effects of PrEP medication; awareness about PrEP before the survey, number of full time pharmacists in their pharmacy, and increases in new HIV cases from 2015 to 2016 in communities served. Comfort counseling about PrEP was associated with the belief that pharmacists can be an important resource for HIV and HCV treatment.

The role of the dorsolateral funiculi in the pain relieving effect of spinal cord stimulation: a study in a rat model of neuropathic pain.

Activation of the dorsal columns is relayed to supraspinal centers, involved in pain modulation, probably via the descending fibers in the dorsolateral funiculi (DLF). The present study examines the role of the DLF in the attenuation of pain-related signs by spinal cord stimulation (SCS). Several groups of rats were subjected to nerve injury and to chronic bilateral DLF lesions at C5-7 level. In each animal, two sets of miniature electrodes were implanted, a caudal system placed in the dorsal epidural space at low thoracic level and another implanted over the dorsal column nuclei, rostral to the lesions. Stimulation (50 Hz, 0.2 ms; 70 % of motor threshold) was applied for 5 min via either of the electrodes. Behavioral tests were used to assess the effects of SCS on the nerve injury-induced mechanical and cold hypersensitivity and heat hyperalgesia. Prior to application of SCS, antagonists to either of GABAA or B, 5-HT1 or 1-2 or α/ß-adrenergic receptors were injected i.p. Both stimulations produced comparable decreases (80-90 % of the control) of neuropathic manifestations in rats with intact spinal cords. DLF lesions attenuated the effects of both types of stimulation by about 50 %. Pretreatment with receptor antagonists differentially counteracted the effects of rostral and caudal stimulation; the inhibition with rostral stimulation generally being more prominently influenced. These results provide further support to the notion of important involvement of brainstem pain modulating centers in the effects of SCS. A major component of the inhibitory spinal-supraspinal-spinal loop is mediated by fibers running in the DLF.

Dialing for doctors: Secret shopper study of Arizona methadone and buprenorphine providers, 2022.

INTRODUCTION: Methadone and buprenorphine are effective and safe treatments for opioid use disorder (OUD) and also reduce overdose and all-cause mortality. Identifying and reaching providers of medication for opioid use disorder (MOUD) has proven difficult for prospective patients and researchers. OBJECTIVES: To assess the accuracy of government-maintained lists of Arizona (AZ) providers prescribing MOUD, and the extent to which these providers are accessible for treatment. METHODS: A two-phase study used a listing of 2376 AZ MOUD providers obtained from the U.S. Drug Enforcement Administration and the Substance Abuse and Mental Health Services Administration. Phase 1 assessed the accuracy of the listing using internet confirmatory research from May-October 2022. Phase 2 used the resulting list of 838 providers to assess provider availability, type of MOUD treatment provided, and accepted payment through secret shopper calls between November 16 and 30, 2022. RESULTS: Just over half (52.2 %, n = 1240) of providers were removed from the original listing during Phase 1. One quarter (25.9 %) were no longer in practice. Among the 833 eligible for the secret shopper Phase 2 study, 36.6 % (n = 307) were reached and identified as providing MOUD. A vast majority (88.1 %) of MOUD providers indicating treatment type were accepting new patients, however methadone was identified far more frequently than was likely permitted or provided for OUD. Providers were 5.5 times more likely to accept new patients if they accepted cash payment for services, and 4.9 times more likely if they accepted Medicaid. Rural areas remained underserved. CONCLUSIONS: The active population of MOUD providers is far smaller than surmised. DEA and SAMHSA provider listings are not sufficiently accurate for survey research sampling. Other means of representative sampling will need to be devised, and trusted lists of providers for prospective patients should be promoted, publicly available, and regularly maintained for accuracy. Providers that offer treatment should assure that public-facing staff have basic information about the practice, the treatment offered, and conditions for taking new patients. Concerted efforts must assure rural access at the most local levels to reduce patient travel burden.

ASAP: A pharmacy-level intervention to increase nonprescription syringe sales to reduce bloodborne illnesses.

BACKGROUND: Pharmacy syringe sales are effective structural interventions to reduce bloodborne illnesses in populations, and are legal in all but two states. Yet evidence indicates reduced syringe sales in recent years. This study was designed as a feasibility test of an intervention to promote syringe sales by pharmacies in Arizona. METHODS: A four-month pilot among three Arizona pharmacies measured feasibility and acceptability through monthly surveys to 18 enrolled pharmacy staff members. RESULTS: Pharmacy staff reported increased ease of dispensing syringes across the study. Rankings of syringe dispensing as 'easiest' among 6 measured pharmacy practices increased from 38.9 % at baseline to 50.1 % post intervention module training, and to 83.3 % at pilot conclusion. The majority (72.2 %) of pharmacy staff agreed that intervention materials were easy to use. Over 70 % indicated that the intervention was influential in their "being more open to selling syringes without a prescription to someone who might use them for illicit drug use," and 61.1 % reported that in the future, they were highly likely to dispense syringes to customers who would use them to inject drugs. A vast majority (92 %) reported being likely to dispense subsidized naloxone if available to their pharmacy at no cost. CONCLUSIONS: An education-based intervention was found to be feasible and acceptable to pharmacy staff and had an observed impact on perceptions of ease and likelihood of dispensing syringes without a prescription to people who may use them to inject drugs.

Feasibility and acceptability of a proposed pharmacy-based harm reduction intervention to reduce opioid overdose, HIV and hepatitis C.

BACKGROUND: Evidence-based harm reduction intervention components which might benefit pharmacy patients have not been integrated and studied. OBJECTIVE: To investigate the feasibility and acceptability of a proposed pharmacy-based harm reduction intervention to reduce opioid overdose, HIV and hepatitis C called PharmNet. METHODS: Indiana managing pharmacists were surveyed in 2018 to assess the feasibility and acceptability of an intervention for opioid misuse screening, brief intervention, syringe and naloxone dispensing, and referrals provision. The Consolidated Framework for Implementation Research informed the survey development and analysis. RESULTS: The sample included 303 (30.8%) pharmacists; 215 (70.9%) provided detailed written comments. Intervention Characteristics: 83.3% believed PharmNet would benefit patients, and that staff could deliver the intervention with adequate training (70.0%). Inner Setting: While 77.2% believed their pharmacy culture supported practice change, 57.5% of chain pharmacists believed their pharmacies would not have time for PharmNet. Outer Setting: 73.3% believed additional addiction and overdose screening is needed in their community, and pharmacies should offer new services to help reduce opioid overdose and addiction among their patients (79.5%). A vast majority (97.7%) were asked by patients in the past 2 years about syringe related issues; 67.7% were asked about syringes for non-prescription injection drug use. Individuals Involved: While 62.4% believed PharmNet was within pharmacy scope of practice and 90.1% were comfortable consulting about syringe use, pharmacists reported that they had limited control over the implementation environment. PROCESS: 38.0% of pharmacists indicated interest in advising the development of PharmNet. CONCLUSIONS: An implementation trial of a modified version of PharmNet is likely feasible; yet will be challenged by structural pressures particularly in chain pharmacies. Successful implementation will involve the development of resources and policy components to manage outer and inner setting characteristics and align the intervention to the implementation environment.

Multicentre European study of thalamic stimulation for parkinsonian tremor: a 6 year follow-up.

AIM: To evaluate the results of ventral intermediate (Vim) thalamic deep brain stimulation (DBS) in patients with tremor predominant Parkinson's disease (PD) at 6 years post surgery. METHODS: This was a prolonged follow-up study of 38 patients from eight centres who participated in a multicentre study, the 1 year results of which have been published previously. Total scores as well as scores for individual items of the motor part and the disability part of the Unified Parkinson's Disease Rating Scale were used for evaluation. RESULTS: Tremor was still effectively controlled by DBS and appendicular rigidity and akinesia remained stable compared with baseline. Axial scores (speech, gait and postural instability), however, worsened, and in parallel the initial improvement in activities of daily living scores at the 1 year follow-up had disappeared at 6 years, despite sustained improvement of tremor. Remarkably, neither daily doses of dopaminergic medication nor fluctuations and dyskinesias had changed at 6 years compared with baseline in this particular patient group. CONCLUSION: This study confirms that patients with tremor dominant PD who do not present with fluctuations and dyskinesias may have a relatively benign progression of the disease. Vim DBS, although having no effect on akinesia and rigidity, is a relatively lenient surgical procedure and may still have a place for long term symptomatic control of PD tremor in selected patients.

Assessing HIV care and unmet need: eight data bases and a bit of perseverance.

This study integrated healthcare information from multiple data sources to measure access to HIV primary care in the St. Louis, Missouri area between 1998-2002. We describe the process of creating the collective database and the degree to which each dataset contributed to the calculation of global variables such as evidence of HIV primary care. Descriptive analyses were used to measure evidence of HIV primary among the included data sources. This study was the first of its kind to study HIV primary healthcare access over a period of five years with integrated databases. Findings reinforce the importance of HIV laboratory values as indicators of access to HIV primary healthcare, particularly in the absence of other health data sets. Limitations to the study were posed by data availability and integration of data sources with varying purposes and sophistication.

Predicting pharmacy naloxone stocking and dispensing following a statewide standing order, Indiana 2016.

BACKGROUND: While naloxone, the overdose reversal medication, has been available for decades, factors associated with its availability through pharmacies remain unclear. Studies suggest that policy and pharmacist beliefs may impact availability. Indiana passed a standing order law for naloxone in 2015 to increase access to naloxone. OBJECTIVE: To identify factors associated with community pharmacy naloxone stocking and dispensing following the enactment of a statewide naloxone standing order. METHODS: A 2016 cross-sectional census of Indiana community pharmacists was conducted following a naloxone standing order. Community, pharmacy, and pharmacist characteristics, and pharmacist attitudes about naloxone dispensing, access, and perceptions of the standing order were measured. Modified Poisson and binary logistic regression models attempted to predict naloxone stocking and dispensing, respectively. RESULTS: Over half (58.1%) of pharmacies stocked naloxone, yet 23.6% of pharmacists dispensed it. Most (72.5%) pharmacists believed the standing order would increase naloxone stocking, and 66.5% believed it would increase dispensing. Chain pharmacies were 3.2 times as likely to stock naloxone. Naloxone stocking was 1.6 times as likely in pharmacies with more than one full-time pharmacist. Pharmacies where pharmacists received naloxone continuing education in the past two years were 1.3 times as likely to stock naloxone. The attempted dispensing model yielded no improvement over the constant-only model. CONCLUSIONS: Pharmacies with larger capacity took advantage of the naloxone standing order. Predictors of pharmacist naloxone dispensing should continue to be explored to maximize naloxone access.

Intraputaminal infusion of nerve growth factor to support adrenal medullary autografts in Parkinson's disease. One-year follow-up of first clinical trial.

Experimental studies in rodents show that beta-nerve growth factor can increase the survival, neurite outgrowth, and functional effect of grafts of adrenal chromaffin cells to the basal ganglia. We, therefore, have begun to investigate whether treatment with nerve growth factor might also increase the functional effect of autografts of adrenal medullary tissue in patients with Parkinson's disease. Previous studies have shown that stereotactic implantation of adrenal tissue pieces produces a transient functional improvement that lasts for a few months. This report describes a trial of grafting of adrenal chromaffin tissue into the putamen, supported by infusion of nerve growth factor. The patient is a 63-year-old woman with a 19-year history of Parkinson's disease, now complicated by on-off phenomena and drug-induced hyperkinesia, despite optimized medical management. The left adrenal gland was removed, and the medulla was dissected into 1- to 2-mm3 pieces in a solution containing nerve growth factor purified from mouse submandibular gland. Pieces were implanted in six tracts 3 to 4 mm from a previously placed cannula in the left putamen. Through the cannula, nerve growth factor was infused for 23 days for a total dose of 3.3 mg. Clinical assessment consisted of global ratings for rigidity and/or hypokinesia and for drug-induced hyperkinesia. Measures of gait and fine-motor control were also made. The motor readiness potential and auditory evoked potentials were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of analgesic effect of opioids on neuropathic and idiopathic forms of pain.

The aim of the present study has been to assess the responsiveness of various types of chronic pain to opioids given i.v. and tested against placebo in a double-blind, randomized fashion. Pain classified as primary nociceptive was effectively alleviated (P greater than 0.001) while neuropathic deafferentation pain was not significantly influenced by morphine or equivalent doses of other opioids. Also 'idiopathic' pain, defined as chronic pain with no or little demonstrable pathology, failed to respond. The results were not related to whether the patients were regular users of narcotic analgesics or not. The outcome of our double-blind opioid test has proved useful to justify a continued, or discontinued, use of narcotic medication in individual patients. It may also support the indication and choice of invasive stimulation procedures (spinal cord or brain). The results of the study illustrate the misconception of chronic pain as an entity and highlight the importance of recognizing different neurobiological mechanisms and differences in responsiveness to analgesic drugs as well as to non-pharmacological modes of treatment. The opioid test has thus become a valuable tool in pain analysis and helpful as a guide for further treatment.

Influence on touch, vibration and cutaneous pain of dorsal column stimulation in man.

Five patients out of a group of ten who had dorsal column electrodes implanted for the relief of chronic pain were examined for the influence of the stimulation on the spontaneous pain and on the thresholds for touch, vibration and cutaneous pain induced by pinching. Stimulation producing paraesthesias resulted in an almost immediate abolishment of spontaneous pain and was accompanied by significant elevations of both tactile and vibratory thresholds. Elevation of thresholds was confined to segments below the site of implantation and occurred bilaterally also when the paraesthesias were restricted to one side. The changes of thresholds generally persisted for some time after the stimulation but these effects were short lasting in comparison with the effect on spontaneous pain. Elevation of sensory thresholds is presumably not due to blocking of the primary neurones but to central inhibitory mechanisms. The thresholds for induced cutaneous pain were not influenced by dorsal column stimulation except for one case in whom an abnormally low threshold within an hyperaestethic area became normalized.

Effects of spinal cord stimulation on touch-evoked allodynia involve GABAergic mechanisms. An experimental study in the mononeuropathic rat.

There is much evidence that tactile allodynia in rat models of mononeuropathy produced by sciatic nerve constriction is linked to disturbance of spinal GABAergic functions. Spinal cord stimulation (SCS) applied to such animals via chronically implanted electrodes may in some of the animals induce a significant increase of the withdrawal threshold in response to innocuous mechanical stimulation with von Frey filaments applied to the paw of the nerve ligated leg. The present study was performed in mononeuropathic animals with definite signs of tactile allodynia, which did not respond to SCS, GABA and the GABAB-agonist baclofen were administered intrathecally, in doses per se insufficient to influence the withdrawal thresholds, together with the previously ineffective SCS. This combination resulted in a marked and long-lasting increase of the thresholds. The GABAA-agonist muscimol given together with SCS also produced a similar, but less prominent threshold increase. The GABAB-antagonist 5-aminovaleric acid (5-AVA) produced a transient suppression of the threshold increase induced by SCS together with either GABA or baclofen. In contrast, the GABAA-antagonist bicuculline had no apparent inhibitory effect on the threshold augmentation produced by SCS combined with GABA or baclofen. It is concluded that SCS may operate by upgrading the spinal GABAergic systems and that its potential for producing pain relief is dependent upon the availability of responsive GABA-containing inhibitory interneurons. Moreover, it seems that the effects of SCS are more linked to the GABAB-than to the GABAA-receptor system.

Spinal cord stimulation attenuates dorsal horn neuronal hyperexcitability in a rat model of mononeuropathy.

The mechanisms underlying the relief of neuropathic pain of peripheral origin by spinal cord stimulation (SCS) are poorly understood. The present study was designed to investigate the effects of SCS on evoked and spontaneous discharges in dorsal horn neurons in intact and in nerve-injured rats subjected to partial sciatic nerve ligation according to Seltzer et al. (1990). Tactile sensitivity in the hind paw was assessed in behavioral tests using von Frey filaments. The presence of 'allodynia' was defined as a withdrawal response to a filament of 10 g or less. Under halothane/oxygen anesthesia the effects of SCS (50 Hz, 0.2 ms, 80-620 microA, 5 min.) on mechanically evoked (brush and innocuous press on the hind paw) responses and spontaneous discharges were investigated in wide-dynamic range (WDR) neurons in three groups of animals: (1) rats that displayed 'allodynia' after nerve ligation (2) rats without signs of 'allodynia' after surgery and (3) control, intact rats. A significantly increased frequency of spontaneous discharge and of responsiveness to brush and press was found in the group of allodynic, as compared with non-allodynic and control rats. The majority (63%) of the investigated neurons in these animals displayed afterdischarge in response to press stimulation. SCS induced a significant depression of both the principal response and the afterdischarge in allodynic rats: the discharge during brush stimulation was reduced to 86 +/- 8.2% and during press to 77.4 +/- 4.5% as compared with the prestimulation value. These depressive effects on evoked responses in allodynic rats outlasted SCS by 10.5 +/- 1.7 min during which time the responses gradually recovered. The frequency of spontaneous discharge was markedly decreased in approximately one third of the neurons, whereas in another third it was increased. In non-allodynic and control rats, SCS had no significant depressive effects on the evoked responses and spontaneous discharge. The results suggest that SCS may provide a suppressive action on dorsal horn neuronal hyperexcitability associated with signs of peripheral neuropathy. The suppressive effect of SCS on tactile allodynia, as previously observed in behavioral experiments, presumably corresponds to a normalization of the excitability of WDR cells in response to innocuous stimuli.

Spinal cord stimulation in animal models of mononeuropathy: effects on the withdrawal response and the flexor reflex.

Spinal cord stimulation (SCS) is efficacious for pain due to injury of peripheral nerves, and therefore models of mononeuropathy appear to be particularly suitable for an experimental approach to the study of mechanisms underlying the clinical effect of this mode of treatment in chronic neuropathic pain. Virtually all previous experimental studies on SCS have utilized acute and nociceptive types of peripheral pain stimuli to explore the attenuating effects of SCS. In the present study we made use of the two models of supposedly painful neuropathy developed by Bennett and Xie (1988) and Seltzer et al. (1990) to explore the effect of SCS applied with stimulus parameters similar to those used in clinical practice. In rats subjected to ligatures of the sciatic nerve according to these two methods, SCS was applied via chronically implanted electrodes, or acutely via a laminectomy in the lower thoracic region. In awake, freely moving animals SCS produced a marked increase of the withdrawal thresholds to innocuous mechanical stimuli in the form of von Frey filaments. This threshold elevation lasted for up to 40 min after 10 min of SCS. In about one-half of the animals there was also a moderate, but short-lasting increase in the intact leg. The degree and duration of the withdrawal threshold elevation was clearly related to the intensity of SCS which was kept below the level of which a response in the thoracic or leg musculature was produced. In a second series of experiments the effect of SCS, applied acutely via a laminectomy, on the early component (latency: 8-12 msec) of the flexor reflex was studied. As a result of nerve ligation with either of the methods used, the thresholds for evoking the early as well as the late component in the nerve-ligated leg were significantly lower than in the intact one. SCS resulted in a marked and long-lasting increase of the threshold of the early component in the nerve-ligated leg. On the intact side only a slight and short-lasting increase was observed. The late, C fibre-mediated component was not influenced by SCS. The first component of the flexor reflex is conceivably mediated by A beta-fibre activation and it presumably corresponds to the withdrawal response induced by innocuous mechanical stimuli. The lack of effect of SCS on the late reflex component indicates that it selectively influences transmission of A-fibre activity. (ABSTRACT TRUNCATED AT 400 WORDS)

Spinal cord stimulation attenuates augmented dorsal horn release of excitatory amino acids in mononeuropathy via a GABAergic mechanism.

Neuropathic pain may be effectively relieved by electric stimulation of the spinal cord (SCS). However, the underlying mechanisms for the ensuing pain relief are poorly understood. In a rat model of neuropathy displaying hypersensitivity to innocuous tactile stimuli, (allodynia), we have earlier demonstrated that SCS may normalise withdrawal response thresholds. In the present study, using microdialysis, it is shown that SCS induces a decreased release of the dorsal horn excitatory amino acids (EAA), glutamate and aspartate, concomitant with an increase of the GABA release. Local perfusion with a GABA(B)-receptor antagonist in the dorsal horn transiently abolishes the SCS-induced suppression of the EAA release. Thus, the effect of SCS on neuropathic pain and allodynia may be due to an activation of local GABAergic mechanisms inhibiting the EAA release which is chronically elevated in such conditions.

The ontogeny of tolerance to the 5-HT1A agonist 8-OH-DPAT: a study in the rat.

The 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) induces hypothermia and a flat body posture in rats. Tolerance to 8-OH-DPAT develops in adult rats with regard to these responses. The ontogeny of the ability to induce tolerance to the hypothermia and the flat body posture elicited by 8-OH-DPAT was studied. Rat pups of both sexes were given 8-OH-DPAT, 100 micrograms/kg (0.352 mumol/kg) or saline for 1, 4 or 12 days between 22 and 34 days of age. At 26 days of age no attenuation was induced by treatment during the previous 4 days. In contrast, at 34 days of age there was a clear attenuation of both responses induced by 8-OH-DPAT after an analogous 4 day treatment. The data indicate that the ability to induce tolerance to 8-OH-DPAT is not developed before 26 days of age in the rat.

Daily spinal cord stimulation suppresses autotomy behavior in rats following peripheral deafferentation.

Autotomy in experimental animals following peripheral nerve section has been interpreted as a sign of pain corresponding to the chronic pain observed in patients with extensive nerve lesions. Such pain may be alleviated by spinal cord stimulation. In the present study, the effect of such stimulation, via chronically implanted electrodes, on autotomy behavior following sciatic nerve section was assessed in the rat. The stimulation was applied for 30 min daily during a 10-day period. There were four groups of animals, 16 in each, half of them females. Stimulating electrodes were implanted in all and one group served as control, receiving sham stimulation. In one group, the stimulation was started when autotomy was observed, one received stimulation from the day of nerve section, and in one it was begun three days before section. The onset of autotomy was significantly delayed in the latter two groups. When stimulation was applied as "treatment", autotomy ceased but reappeared after the 10-day stimulation period. The incidence and severity of autotomy was markedly delayed and reduced when the stimulation had been applied just after the nerve section or before. In the latter groups, the diminished degree of autotomy persisted for the entire observation period, lasting 60 days after the stimulation was stopped. It seems that spinal cord stimulation, albeit applied only once daily and during a limited time period, can protect the spinal cord from developing the state of hyperexcitability believed to be the major cause of autotomy behavior. Peripheral mechanisms may also play a role by the antidromic activity evoked by the stimulation in the sectioned peripheral nerve. This study shows that spinal cord stimulation, which is a commonly employed method for treating chronic neurogenic pain, may have long-lasting effects on plasticity changes in the spinal cord following peripheral nerve injury, even when the stimulation is applied for short periods of time.

Regulation of galanin and neuropeptide Y in dorsal root ganglia and dorsal horn in rat mononeuropathic models: possible relation to tactile hypersensitivity.

The expression of galanin and neuropeptide Y in rat lumbar 5 (L5) dorsal root ganglia and dorsal horn (L4-5) was studied after four types of peripheral nerve injury using immunohistochemistry and in situ hybridization. The possible correlation between these two peptides and tactile allodynia-like behaviour was analysed as well. The models employed were the Gazelius (photochemical lesion) and Seltzer and Bennett (constriction lesions) models, as well as complete sciatic nerve transection (axotomy). Two weeks after surgery, the Gazelius model rats more frequently displayed a greater tactile allodynia than the rats from the Seltzer and Bennett models. Tactile allodynia was not observed in any of the axotomized rats. A marked increase in the number of galanin-immunoreactive and galanin messenger RNA-positive neuron profiles was observed in ipsilateral dorsal root ganglia in all types of models. The increase in allodynic rats (Gazelius, Seltzer and Bennett models) was less pronounced than that after axotomy. In addition, in the Bennett model the number of galanin-immunoreactive neurons was significantly lower in allodynic rats as compared to non-allodynic rats, and the same tendency, but less obvious was found in the Seltzer model. Furthermore, an increase in galanin-immunoreactive fibres was found in the superficial laminae of the ipsilateral dorsal horn in all lesion models, especially in lamina II. A dramatic increase in the number of neuropeptide Y and neuropeptide Y messenger RNA-positive neuron profiles was also found in the ipsilateral dorsal root ganglia in all models, but no significant difference was found in peptide levels between allodynic and non-allodynic rats in any of the models. The present results suggest that the levels of endogenous galanin may play a role in whether or not allodynia develops in the Bennett model.

Functional changes in GABAA receptor stimulation during the oestrous cycle of the rat.

1. Slices of rat cuneate nucleus were used to study whether or not gonadal steroids influence the gamma-aminobutyric acid (GABA) system in vivo. Females in different stages of the oestrous cycle as well as steroid-treated (oestrogen, progesterone or both) ovariectomized animals were used. 2. Functional changes in the GABAA receptors were assayed using the effects of potentiators (benzodiazepine, barbiturate) and antagonists (picrotoxin) on the muscimol control dose-response curves. 3. The potentiating effect of the benzodiazepine, flurazepam was unchanged during the oestrous cycle, and the hormone treatments did not alter this effect. 4. During oestrus, an increase was seen in the potentiating effect of the barbiturate (pentobarbitone). This suggests a synergistic effect between barbiturates and gonadal steroids. Progesterone treatment also increased the effect of pentobarbitone. 5. The antagonistic action of picrotoxin was unaffected during the oestrous cycle. However, progesterone (or progesterone and oestrogen) treatment reduced the potency of picrotoxin. 6. This study supports the idea that endogenous steroids (presumably progesterone) affect the GABAA receptors during the oestrous cycle by a mechanism associated with the barbiturate site of the GABAA receptor complex.

Influence of early beta-endorphin treatment on the behavior and reaction to beta-endorphin in the adult male rat.

A study was made of the influence of early exposure to beta-endorphin (beta-END) on the adult behavior and response to beta-END in male rats. beta-END was given during a neonatal period, at 1-5 days of age (1 microgram/animal/day s.c.). Recordings of the development of home-nest-orientation ability, body weights, and sex-specific approach behavior showed that the early beta-END treatment did not have debilitating or other non-specific effects. The early beta-END treatment did cause significant changes in the establishment of the adult pattern of sex-specific approach behavior. Copulatory behavior was not apparently influenced. Intracerebroventricular injection of beta-END (1 microgram) at an adult age induced changes in exploratory and copulatory behaviors and in the pattern of sex-specific approach behavior. The reaction to this treatment with respect to components of socio-sexual behavior differed significantly between males treated early with beta-END and their corresponding controls. No differences were observed in behaviors in the exploratory test situation. It is concluded that early beta-END treatment in rats influences components of socio-sexual behavior and the response to exogenous beta-END in adulthood.