Exploring cognitive apprenticeship and teaching practices in pharmacy education.

Health professions schools in the United States and internationally have engaged in curricular changes to better prepare students for the future of health care. However, designing or selecting evidence-based teaching activities can be a challenge. Research suggests the Cognitive Apprenticeship theory is an effective framework for the health professions to inform instruction design, yet these studies have mainly focused on the clinical setting and not the didactic learning environment. This study used qualitative methods to explore the Cognitive Apprenticeship framework in the didactic learning environment and the teaching practices that pharmacy faculty used to explicate their expert thinking to students. Faculty were observed using all four Cognitive Apprenticeship dimensions (ie, Content, Sequencing, Methods, Sociology) in their teaching practice. Patterns were observed in the data revealing complex, short and sometimes spontaneous teaching practices that faculty used to promote learning.

Positive Allosteric Modulation of the Muscarinic M1 Receptor Improves Efficacy of Antipsychotics in Mouse Glutamatergic Deficit Models of Behavior.

Current antipsychotics are effective in treating the positive symptoms associated with schizophrenia, but they remain suboptimal in targeting cognitive dysfunction. Recent studies have suggested that positive allosteric modulation of the M1 muscarinic acetylcholine receptor (mAChR) may provide a novel means of improving cognition. However, very little is known about the potential of combination therapies in extending coverage across schizophrenic symptom domains. This study investigated the effect of the M1 mAChR positive allosteric modulator BQCA [1-(4-methoxybenzyl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid], alone or in combination with haloperidol (a first-generation antipsychotic), clozapine (a second-generation atypical antipsychotic), or aripiprazole (a third-generation atypical antipsychotic), in reversing deficits in sensorimotor gating and spatial memory induced by the N-methyl-d-aspartate receptor antagonist, MK-801 [(5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine]. Sensorimotor gating and spatial memory induction are two models that represent aspects of schizophrenia modeled in rodents. In prepulse inhibition (an operational measure of sensorimotor gating), BQCA alone had minimal effects but exhibited different levels of efficacy in reversing MK-801-induced prepulse inhibition disruptions when combined with a subeffective dose of each of the three (currently prescribed) antipsychotics. Furthermore, the combined effect of BQCA and clozapine was absent in M1-/- mice. Interestingly, although BQCA alone had no effect in reversing MK-801-induced memory impairments in a Y-maze spatial test, we observed a reversal upon the combination of BQCA with atypical antipsychotics, but not with haloperidol. These findings provide proof of concept that a judicious combination of existing antipsychotics with a selective M1 mAChR positive allosteric modulator can extend antipsychotic efficacy in glutamatergic deficit models of behavior.

Male contraception via simultaneous knockout of α1A-adrenoceptors and P2X1-purinoceptors in mice.

Therapeutic targets for male contraception are associated with numerous problems due to their focus on disrupting spermatogenesis or hormonal mechanisms to produce dysfunctional sperm. Here we describe the dual genetic deletion of α1A-adrenergic G protein-coupled receptors (adrenoceptors) and P2X1-purinoceptor ligand gated ion channels in male mice, thereby blocking sympathetically mediated sperm transport through the vas deferens during the emission phase of ejaculation. This modification produced 100% infertility without effects on sexual behavior or function. Sperm taken from the cauda epididymides of double knockout mice were microscopically normal and motile. Furthermore, double knockout sperm were capable of producing normal offspring following intracytoplasmic sperm injection into wild-type ova and implantation of the fertilized eggs into foster mothers. Blood pressure and baroreflex function was reduced in double knockout mice, but no more than single knockout of α1A-adrenoceptors alone. These results suggest that this autonomic method of male contraception appears free of major physiological and behavioral side effects. In addition, they provide conclusive proof of concept that pharmacological antagonism of the P2X1-purinoceptor and α1A-adrenoceptor provides a safe and effective therapeutic target for a nonhormonal, readily reversible male contraceptive.

Biased Agonism and Biased Allosteric Modulation at the CB1 Cannabinoid Receptor.

CB1 cannabinoid receptors (CB1Rs) are attractive therapeutic targets for numerous central nervous system disorders. However, clinical application of cannabinoid ligands has been hampered owing to their adverse on-target effects. Ligand-biased signaling from, and allosteric modulation of, CB1Rs offer pharmacological approaches that may enable the development of improved CB1R drugs, through modulation of only therapeutically desirable CB1R signaling pathways. There is growing evidence that CB1Rs are subject to ligand-biased signaling and allosterism. Therefore, in the present study, we quantified ligand-biased signaling and allosteric modulation at CB1Rs. Cannabinoid agonists displayed distinct biased signaling profiles at CB1Rs. For instance, whereas 2-arachidonylglycerol and WIN55,212-2 [(R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-napthalenylmethanone] showed little preference for inhibition of cAMP and phosphorylation of extracellular signal-regulated kinase 1/2 (pERK1/2), N-arachidonoylethanolamine (anandamide), methanandamide, CP55940 [2-[(1R,2R,5R)-5-hydroxy-2-(3-hydroxypropyl)cyclohexyl]-5-(2-methyloctan-2-yl)phenol], and HU-210 [11-hydroxy-Δ(8)-THC-dimethylheptyl] were biased toward cAMP inhibition. The small-molecule allosteric modulator Org27569 [5-chloro-3-ethyl-1H-indole-2-carboxylic acid [2-(4-piperidin-1-yl-phenyl)ethyl]amide] displayed biased allosteric effects by blocking cAMP inhibition mediated by all cannabinoid ligands tested, at the same time having little or no effect on ERK1/2 phosphorylation mediated by a subset of these ligands. Org27569 also displayed negative binding cooperativity with [(3)H]SR141716A [5-(4-chlorophenyl)-1-(2,4-dichloro-phenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide]; however, it had minimal effects on binding of cannabinoid agonists. Furthermore, we highlight the need to validate the reported allosteric effects of the endogenous ligands lipoxin A4 and pregnenolone at CB1Rs. Pregnenolone but not lipoxin A4 displaced [(3)H]SR141716A, but there was no functional interaction between either of these ligands and cannabinoid agonists. This study demonstrates an approach to validating and quantifying ligand-biased signaling and allosteric modulation at CB1Rs, revealing ligand-biased "fingerprints" that may ultimately allow the development of improved CB1R-targeted therapies.

Pharmacist-led screening for mental illness: A systematic review.

BACKGROUND: Early identification and treatment of mental illnesses is imperative for optimal patient outcomes. Pharmacists may play an important role in mental healthcare through the provision of screening services for mental illnesses. OBJECTIVE: (s): To systematically review the impact of pharmacist-led mental illness screening on clinical or patient-reported outcomes and identify and report any follow-up or referral systems used in pharmacist-led screening interventions for mental illnesses. METHODS: A systematic review was conducted by searching MEDLINE, CINAHL, Embase and APA PsycInfo via EBSCOhost from inception to 9 March 2023 to identify studies involving pharmacist-led screening interventions for mental illnesses. Data was collected on the mental illness in question, setting and population characteristics, screening tools used, clinical or patient-reported outcomes, and follow-up and referral systems reported. RESULTS: Twenty six studies were identified that related to screening for mental illnesses, such as depressive disorders and substance use disorders. There were a variety of study designs, including uncontrolled studies (n = 23), pre-post studies (n = 2) and randomised controlled trials (n = 1). Screening was conducted in different settings, with most studies conducted in community pharmacies (n = 21/26, 87.8 %) and focusing on depression screening (n = 12/26, 46.1 %). A range of follow-up and referral methods to other healthcare professionals were reported, including verbal (n = 3/26, 11.5 %), both written and verbal (n = 3/26, 11.5 %), communications via electronic health record (n = 2/26, 7.7 %) and written (n = 1/26, 3.8 %). CONCLUSIONS: Pharmacists provide screening for a variety of mental illnesses in different settings. Various referral methods and follow-up pathways may be utilised for post-screening patient care. However, current evidence is insufficient to establish improvements in early detection, treatment, or outcomes. Further large, well-designed studies are required to support the role of pharmacists in mental illness screening, provide evidence on the impact of pharmacist-led mental illness screening services and inform the most effective follow up and referral methods.

Barriers and facilitators to implementing simulation into pharmacy programs globally.

BACKGROUND: MyDispense is a simulation software developed by Monash University that has been utilized by over 200 institutions worldwide to educate pharmacy students. However, little is known about the processes by which it is used to teach dispensing skills to students and how they use it to facilitate critical thinking in an authentic environment. This study aimed to understand and investigate how simulations are used to teach dispensing skills in pharmacy programs globally, and to determine the opinions, attitudes and experiences of pharmacy educators towards MyDispense and other simulation software within their pharmacy program. METHODS: Purposive sampling was used to identify pharmacy institutions for the study. A total of 57 educators were contacted, 18 responded to the study invitation, 12 were MyDispense users and 6 were non-users. Two investigators conducted an inductive thematic analysis to generate key themes and subthemes to provide insight into the opinions, attitudes and experiences towards MyDispense and other simulation software used specifically for dispensing within pharmacy programs. RESULTS: 26 pharmacy educators were interviewed, of which 14 were individual interviews and four were group interviews. Intercoder reliability was investigated and a Kappa coefficient of 0.72 indicated substantial agreement between both coders. Five main themes were identified: "dispensing and counseling", which encompassed discussions about how dispensing techniques were taught, the time allocated for students to practice their skills and the use of software other than MyDispense; "description of MyDispense use" includes discussions about the setup of the software, how dispensing skills were taught prior to using MyDispense as well as its use in student assessments; "barriers to MyDispense use", covers discussions about the obstacles users have faced; "facilitators to use MyDispense", includes discussion about the various motivators to using MyDispense and lastly "future use and suggested improvements" of MyDispense are covered by the interviewees. CONCLUSION: The initial outcomes of this project evaluated the awareness and utilization of MyDispense and other dispensing simulations by pharmacy programs globally. By addressing the barriers of use, promotion of the sharing of MyDispense cases can assist in creating more authentic assessments, as well as improving staff workload management. The outcomes of this research will also facilitate the development of a framework for MyDispense implementation, thus streamlining and improving the uptake of MyDispense by pharmacy institutions globally.

Preceptor Perceptions of Pharmacy Student Performance Before and After a Curriculum Transformation.

Objective. To explore preceptors' perceptions about the performance of undergraduate pharmacy students during experiential placements in Australia, before and after curricular transformation.Methods. Using a semi-structured approach, we interviewed 26 preceptors who had recently supervised students who took part in the transformed curriculum and students from the previous curriculum. A directed content analysis approach was used to analyze the transcripts.Results. Preceptors described students from the transformed curriculum as having improved professional skills, behaviors, and attitudes and as having an increased ability to perform clinical activities compared to students of the previous curriculum. Preceptors also perceived that students in the transformed curriculum had improved clinical knowledge and knowledge application. They less frequently expressed that students in the transformed curriculum had lower-than-expected knowledge levels.Conclusion. The results of this study suggest that curricular transformation with a focus on skill-based and active learning can improve the performance of pharmacy students in terms of their professional behaviors and attitudes, skills, knowledge, and clinical abilities, as perceived by preceptors.

Design considerations for cases used in pharmacy teaching and learning using the case difficulty cube.

INTRODUCTION: Learner-centered authentic learning opportunities in health science disciplines can be provided using cases to allow integration of theoretical knowledge across multiple subject areas and development of problem-solving skills. We have previously described the adaptation of the case difficulty cube (CDC), a model from business education, that proposes assignment of case difficulty based on three dimensions (analytical, conceptual, and presentation) in pharmacy education. METHODS: The CDC for use in health science disciplines (modCDC) was evaluated using 13 cases from summative undergraduate pharmacy examinations. Inter-rater agreement (IRA) and inter-rater reliability (IRR) for modCDC ratings were first determined, then a post hoc investigation of the relationship between the modCDC score and student marks was undertaken. RESULTS: First, the IRA for each dimension of the modCDC was adequate for aggregating ratings. IRR was excellent for the conceptual axis, good for the presentation axis, and poor for the analytical axis. Second, analysis of the relationship between the modCDC score and student marks indicated that there was a significant difference between student marks awarded at each level of case difficulty, except for the lower levels of difficulty. The results indicate that the modCDC is a relatively robust tool that could be used to determine case difficulty prior to cases being used in assessments. CONCLUSIONS: The modCDC is a simple tool that can assist academic staff in providing consistent learning opportunities for, and assessment of, pharmacy students at an appropriate level.

The design, synthesis and biological evaluation of novel URB602 analogues as potential monoacylglycerol lipase inhibitors.

We have synthesised an extensive series of URB602 analogues as inhibitors of monoacylglycerol lipase (MAGL), which is the major enzyme responsible for metabolising the endocannabinoid 2-arachidonylglycerol. The recently identified crystal structure of MAGL was used in the design strategy and revealed three possible binding sites for URB602 and the proposed analogues. A test series of carbamate analogues were docked into the identified sites to predict the most favourable binding location. The synthesised analogues of URB602 explored the biological effects of isosteric replacement, ring size and substitution, para substitution of the biphenyl moiety and the incorporation of a bicyclic element. The compounds were tested for their ability to inhibit human MAGL. The carbamate analogue 16 displayed the most significant inhibitory activity, reducing MAGL activity to 26% of controls at 100 µM compared to 73% for the parent compound URB602.

Effect of Changing From Closed-Book to Formulary-Allowed Examinations.

Objective. To determine whether allowing final-year Bachelor of Pharmacy students to use a medicines formulary during examinations modified their learning behaviors and performance, and to investigate students' perceptions about having this resource available during examinations.Methods. Student performance and examination difficulty (as measured by classification of examination questions as high or low according to Bloom's taxonomy of learning) in second semester examinations (formulary allowed) was compared with first semester examinations (closed book) in successive years. Students completed a survey regarding their study and examination approaches and experiences after both semesters.Results. Examinations in semester two had more questions rated higher on Bloom's taxonomy than did examinations in semester one. Data were collected from student surveys for closed book examinations (response rate of 25% and 19% in 2015 and 2016, respectively) and open book examinations (response rate of 22% and 15% in 2015 and 2016, respectively). Students' study approaches, hours studied per week, and anxiety (all self-reported) did not differ between semesters one and two, but students in semester two spent more time studying with a formulary compared with students in semester one. Qualitative analysis of student comments revealed students preferred the formulary-allowed examinations over the closed-book examinations. The majority of students (68%) agreed with the statement: "Knowing that I will have access to the AMH [Australian Medicines Handbook] during the exams allowed me to pay more attention to higher level skills such as analysis and evaluation."Conclusion. When students were allowed to use a formulary for examinations, they studied more using their formulary prior to the examination. Students performed similarly on examinations with a greater proportion of questions addressing higher levels of Bloom's taxonomy and on closed-book examinations that were comparatively less cognitively challenging.

Predictors of Pharmacy Student Performance on Written and Clinical Examinations in a Flipped Classroom Curriculum.

Objective. To examine the effects of student demographics, prior academic performance, course engagement, and time management on pharmacy students' performance on course examinations and objective structured clinical examinations (OSCEs).Methods. Study participants were one cohort of pharmacy students enrolled in a five-year combined Bachelor and Master of Pharmacy degree program at one institution. Variables included student demographics, baseline factors (language assessment and situational judgement test scores), prior academic performance (high school admission rank), course engagement, and student time management of pre-class online activities. Data were collected from course, learning management system, and institutional databases. Data were analyzed for univariate, bivariate, and multivariate associations (four linear regression models) between explanatory factors and outcome variables.Results. Three years of data on 159 pharmacy students were obtained and entered in the dataset. Significant positive predictors of OSCE communication performance included domestic (ie, Australian) student designation, higher baseline written English proficiency, and pre-class online activity completion. Positive predictors of OSCE problem-solving included workshop attendance and low empathy as measured by a baseline situational judgment test (SJT). Positive predictors of performance on year 2 end-of-course examinations included the Australian Tertiary Academic Rank, completing pre-class online activities prior to lectures, and high integrity as measured by an SJT.Conclusion. Several explanatory factors predicted pharmacy students' examination and OSCE performance in the regression models. Future research should continue to study additional contexts, explanatory factors, and outcome variables.

Altered Amygdala Excitation and CB1 Receptor Modulation of Aggressive Behavior in the Neuroligin-3R451C Mouse Model of Autism.

Understanding neuronal mechanisms underlying aggression in patients with autism spectrum disorder (ASD) could lead to better treatments and prognosis. The Neuroligin-3 (NL3)R451C mouse model of ASD has a heightened aggressive phenotype, however the biological mechanisms underlying this behavior are unknown. It is well established that NL3R451C mice have imbalanced excitatory and inhibitory synaptic activity in the hippocampus and somatosensory cortex. The amygdala plays a role in modulating aggressive behavior, however potential changes in synaptic activity in this region have not previously been assessed in this model. We investigated whether aggressive behavior is robustly present in mice expressing the R451C mutation, following back-crossing onto a congenic background strain. Endocannabinoids influence social interaction and aggressive behavior, therefore we also studied the effects of cannabinoid receptor 1 (CB1) agonist on NL3R451C mice. We report that NL3R451C mice have increased amplitude of miniature excitatory postsynaptic currents (EPSCs) with a concomitant decrease in the amplitude of inhibitory postsynaptic currents (IPSCs) in the basolateral amygdala. Importantly, we demonstrated that NL3R451C mice bred on a C57Bl/6 background strain exhibit an aggressive phenotype. Following non-sedating doses (0.3 and 1.0 mg/kg) of the CB1 receptor agonist WIN55,212-2 (WIN), we observed a significant reduction in aggressive behavior in NL3R451C mice. These findings demonstrate altered synaptic activity in the basolateral amygdala and suggest that the NL3R451C mouse model is a useful preclinical tool to understand the role of CB1 receptor function in aggressive behavior.

Impact of a Virtual Dementia Experience on Medical and Pharmacy Students' Knowledge and Attitudes Toward People with Dementia: A Controlled Study.

BACKGROUND: Clinical practice guidelines for dementia highlight the importance of providing patient-centered care. This can be achieved by improving health professionals' attitudes and knowledge toward people with dementia. OBJECTIVE: Quantitatively evaluate the impact of a virtual dementia experience on medical and pharmacy students' knowledge and attitudes toward people with dementia. METHODS: A non-randomized controlled study from September-October 2016. The intervention group received a 1.5-hour multisensory, virtual simulation of light, sound, color, and visual content to experience the cognitive and perceptual difficulties faced by people with dementia. Controls participated in the standard curriculum only. All students were invited to complete the 20-item Dementia Attitudes Scale (DAS) pre- and post-intervention. RESULTS: A total of 278 students (n = 64 medical, n = 214 pharmacy) were analyzed (n = 80 intervention, n = 198 control). The majority of students were female (n = 184, 66.2%), with an average age of 22.5 years. The intervention improved the DAS total score and subdomains of comfort and knowledge (p < 0.001). CONCLUSION: The intervention had a positive impact on medical and pharmacy students' knowledge and attitudes toward people with dementia.

Cannabidiol reverses MK-801-induced disruption of prepulse inhibition in mice.

Cannabidiol, a nonpsychoactive constituent of the Cannabis sativa plant, has been reported to act as an agonist of the vanilloid 1 channel in the transient receptor potential family (TRPV1) and also to inhibit the hydrolysis and cellular uptake of the endogenous cannabinoid anandamide. Cannabidiol has also been reported to have potential as an antipsychotic. We investigated the effect of cannabidiol on sensorimotor gating deficits in mice induced by the noncompetitive NMDA receptor antagonist, MK-801. Sensorimotor gating is deficient in psychotic disorders such as schizophrenia and may be reliably measured by prepulse inhibition (PPI) of the startle response in rodents and humans. MK-801 (0.3-1 mg/kg i.p.) dose dependently disrupted PPI while cannabidiol (1-15 mg/kg i.p.), when administered with vehicle, had no effect on PPI. Cannabidiol (5 mg/kg i.p.) successfully reversed disruptions in PPI induced by MK-801 (1 mg/kg i.p.), as did the atypical antipsychotic clozapine (4 mg/kg i.p.). Pretreatment with capsazepine (20 mg/kg i.p.) prevented the reversal of MK-801-induced disruption of PPI by cannabidiol, providing preliminary evidence that TRPV1 receptors are involved in the reversal of MK-801-induced sensorimotor gating deficits by cannabidiol.

Developing a Framework for Objective Structured Clinical Examinations Using the Nominal Group Technique.

Objective. To use the nominal group technique to develop a framework to improve existing and develop new objective structured clinical examinations (OSCEs) within a four-year bachelor of pharmacy course. Design. Using the nominal group technique, a unique method of group interview that combines qualitative and quantitative data collection, focus groups were conducted with faculty members, practicing pharmacists, and undergraduate pharmacy students. Five draft OSCEs frameworks were suggested and participants were asked to generate new framework ideas. Assessment. Two focus groups (n=9 and n=7) generated nine extra frameworks. Two of these frameworks, one from each focus group, ranked highest (mean scores of 4.4 and 4.1 on a 5-point scale) and were similar in nature. The project team used these two frameworks to produce the final framework, which includes an OSCE in every year of the course, earlier implementation of teaching OSCEs, and the use of independent simulated patients who are not examiners. Conclusions. The new OSCE framework provides a consistent structure from course entry to exit and ensures graduates meet internship requirements.

Detection and quantification of allosteric modulation of endogenous m4 muscarinic acetylcholine receptor using impedance-based label-free technology in a neuronal cell line.

Allosteric modulators of G protein-coupled receptors have the potential to achieve greater receptor subtype selectivity compared with ligands targeting the orthosteric site of this receptor family. However, the high attrition rate in GPCR drug discovery programs has highlighted the need to better characterize lead compounds in terms of their allosteric action, as well as the signals they elicit. Recently, the use of label-free technologies has been proposed as an approach to overcome some limitations of endpoint-based assays and detect global changes in the ligand-stimulated cell. In this study, we assessed the ability of an impedance-based label-free technology, xCELLigence, to detect allosteric modulation in a neuronal cell line natively expressing rodent M4 muscarinic acetylcholine receptors. We were able to demonstrate that positive allosteric modulation of the endogenous M4 muscarinic acetylcholine receptor can be detected using this technology. Importantly, the allosteric parameters estimated from the label-free approach are comparable to those estimated from endpoint-based assays.

The effect of SR 141716 and apomorphine on sensorimotor gating in Swiss mice.

The aim of the present study was to investigate in Swiss mice the acute effects of the CB(1) receptor antagonist N-piperidino-5-(4-chlorphenyl)-1-(2,4-dichlorophenyl)-4-methyl-3-pyrazole-carboxamide (SR 141716) alone and in combination with apomorphine, a D(1)/D(2) receptor agonist, on prepulse inhibition (PPI) of the acoustic startle response, an operational measure of sensorimotor gating. SR 141716 (1 and 3 mg/kg i.p.) had no significant effect on PPI. Apomorphine (3 mg/kg i.p.) significantly disrupted PPI. The PPI of mice injected with SR 141716 (1 mg/kg i.p.) plus apomorphine (3 mg/kg i.p.) was not significantly different to that of vehicle plus apomorphine (3 mg/kg i.p.)-treated mice. However, the higher dose of SR 141716 used (3 mg/kg i.p.) significantly inhibited the disruption of PPI produced by apomorphine. These results suggest that antagonism of CB(1) receptors with SR 141716 has no significant effect on sensorimotor gating in Swiss mice. However, CB(1) receptors appear to be important in the effect of apomorphine on sensorimotor gating, as antagonism of CB(1) receptors with SR 141716 inhibits apomorphine-induced disruptions.

CB2 receptor agonism reverses MK-801-induced disruptions of prepulse inhibition in mice.

RATIONALE: Whilst cannabinoid CB2 receptors were thought to exist predominantly in immune cells in the periphery, the recent discovery of CB2 receptors in the brain has led to an increased interest in the role of these central CB2 receptors. Several studies have reported an association with CB2 receptors and schizophrenia. Sensorimotor gating deficits occur in schizophrenia patients and can be induced in animals using psychotomimetic drugs such as N-methyl-D-aspartate (NMDA) receptor antagonists. OBJECTIVES: The aim of this study was to investigate the effect of CB2 ligands on sensorimotor gating, either alone, or on sensorimotor gating deficits induced by the NMDA receptor antagonist MK-801 in mice. METHOD: The effects of CB2 receptor ligands on prepulse inhibition (PPI), an operational measure of sensorimotor gating, alone or when administrated in combination with MK-801, in Balb-C mice were evaluated. RESULTS: The CB2 receptor agonist JWH015 had no significant effect on PPI alone but reversed disruptions in PPI induced by MK-801. This effect was blocked by co-administration of the CB2 receptor antagonist AM630, but not by co-administration of the CB1 receptor antagonist AM251, indicating a CB2-mediated effect. The mixed CB1/CB2 receptor agonist JWH203 was partially able to reverse MK-801-induced PPI disruptions. Neither the CB2 receptor antagonist AM630 nor the CB1 receptor antagonist AM251 had any significant effect alone or on MK-801-induced disruptions in PPI. CONCLUSIONS: CB2 receptor agonism reversed MK-801 disruptions in sensorimotor gating deficits in mice, indicating that CB2 agonism may have a protective effect against aspects of drug-induced psychosis.

Cannabidiol and clozapine reverse MK-801-induced deficits in social interaction and hyperactivity in Sprague-Dawley rats.

Recently, a novel paradigm has been designed to assess social investigative behaviour in pairs of Sprague-Dawley rats, which involves physical separation whilst ensuring they are able to maintain contact through other social cues. We have modified this set-up in order to assess not just social behaviour but also locomotor activity of the rats. Results showed that the MK-801- (0.3 mg/kg) treated rats displayed reduced social investigative behaviour, hyperactivity as well as reduced attention span. Pretreatment with the phytocannabinoid cannabidiol (3 mg/kg) not only normalised social investigative behaviour but increased it beyond control levels. Pretreatment with clozapine (1, 3 mg/kg) also normalised social investigative behaviour. Both cannabidiol and clozapine inhibited MK-801-induced hyperactivity. However, there were no effects of pretreatment on impairments to attention span. Our findings reinforce several aspects of the validity of the MK-801-induced model of social withdrawal and hyperactivity and also support the use of this novel set-up for further investigations to assess the antipsychotic potential of novel compounds.