Medicine and Health Sciences Commons^™

Behavioral And Pharmacological Investigation Of Anxiety And Maternal Responsiveness Of Postpartum Female Rats In A Pup Elevated Plus Maze, Yu Yang, Jingxue Qin, Weihai Chen, Hong Chen, Ming Li

Department of Psychology: Faculty Publications

The present study investigated the validity of a novel pup-based repeated elevated plus maze task to detect reduced anxiety and increased maternal responsiveness in postpartum female rats and explored the roles of dopamine D2, serotonin transporter and GABA/benzodiazepine receptors in the mediation of these processes. Sprague–Dawley postpartum or nulliparous female rats were tested 4 times every other day on postpartum days 4, 6 and 8 in an elevated plus maze with 4 pups or 4 pup-size erasers placed on each end of the two open arms. When tested with erasers, untreated postpartum mother rats entered the open arms proportionally more …

Drug–Drug Conditioning Between Citalopram And Haloperidol Or Olanzapine In A Conditioned Avoidance Response Model: Implications For Polypharmacy In Schizophrenia, Nathan L. Sparkman, Ming Li

Department of Psychology: Faculty Publications

Patients with schizophrenia often have anxiety and depression, and thus are treated with multiple psychotherapeutic medications. This practice of polypharmacy increases the possibility for drug–drug interactions. However, the pharmacological and behavioral mechanisms underlying drug–drug interactions in schizophrenia remain poorly understood. In the present study, we adopted a preclinical approach and examined a less known behavioral mechanism, drug–drug conditioning (DDC) between haloperidol (a typical antipsychotic) or olanzapine (atypical antipsychotic) and citalopram (a selective serotonin reuptake inhibitor). A rat two-way conditioned avoidance response paradigm was used to measure antipsychotic activity and determine how DDC may alter the antipsychotic efficacy in this model. …

Parametric Studies Of Antipsychotic-Induced Sensitization In The Conditioned Avoidance Response Model: Roles Of Number Of Drug Exposure, Drug Dose, And Test–Retest Interval, Natashia Swalve, Ming Li

Department of Psychology: Faculty Publications

Repeated haloperidol and olanzapine treatment produces an enhanced disruption of avoidance responding, a validated measure of antipsychotic activity. Experimental parameters affecting this sensitization-like effect have not been thoroughly examined. The present study investigated the role of three parameters (number of injections, dose, and interval between initial exposure and challenge) in antipsychotic sensitization in the conditioned avoidance response paradigm. Well-trained Sprague–Dawley rats received different numbers of drug treatment (1–5 days) or different doses of haloperidol (0.025–0.10 mg/kg, subcutaneously) or olanzapine (0.5–2.0 mg/kg, subcutaneously). After certain time intervals (4, 10 or 17 days), they were tested for the expression of haloperidol or …

Neural Basis Of The Potentiated Inhibition Of Repeated Haloperidol And Clozapine Treatment On The Phencyclidine-Induced Hyperlocomotion, Changjiu Zhao, Tao Sun, Ming Li

Department of Psychology: Faculty Publications

Clinical observations suggest that antipsychotic effect starts early and increases progressively over time. This time course of antipsychotic effect can be captured in a rat phencyclidine (PCP)-induced hyperlocomotion model, as repeated antipsychotic treatment progressively increases its inhibition of the repeated PCP-induced hyperlocomotion. Although the neural basis of acute antipsychotic action has been studied extensively, the system that mediates the potentiated effect of repeated antipsychotic treatment has not been elucidated. In the present study, we investigated the neuroanatomical basis of the potentiated action of haloperidol (HAL) and clozapine (CLZ) treatment in the repeated PCP-induced hyperlocomotion. Once daily for five consecutive days, …

Contextual And Behavioral Control Of Antipsychotic Sensitization Induced By Haloperidol And Olanzapine, Chen Zhang, Ming Li

Department of Psychology: Faculty Publications

Repeated administration of haloperidol (HAL) and olanzapine (OLZ) causes a progressively enhanced disruption of the conditioned avoidance response (CAR) and a progressively enhanced inhibition of phencyclidine (PCP)-induced hyperlocomotion in rats (termed antipsychotic sensitization). Both actions are thought to reflect intrinsic antipsychotic activity. The present study examined the extent to which antipsychotic- induced sensitization in one model (e.g. CAR) can be transferred or maintained in another (e.g. PCP hyperlocomotion) as a means of investigating the contextual and behavioral controls of antipsychotic sensitization. Well-trained male Sprague-Dawley rats were first repeatedly tested in the CAR or the PCP (3.2 mg/kg, subcutaneously) hyperlocomotion model …

Time Course Of The Attenuation Effect Of Repeated Antipsychotic Treatment On Prepulse Inhibition Disruption Induced By Repeated Phencyclidine Treatment, Ming Li, Erik He, Nick Volf

Department of Psychology: Faculty Publications

Antagonism of prepulse inhibition (PPI) deficits produced by psychotomimetic drugs has been widely used as an effective tool for the study of the mechanisms of antipsychotic action and identifying potential antipsychotic drugs. Many studies have relied on the acute effect of a single administration of antipsychotics, whereas patients with schizophrenia are treated chronically with antipsychotic drugs. The clinical relevance of acute antipsychotic effect in this model is still an open question. In this study, we investigated the time course of repeated antipsychotic treatment on persistent PPI deficit induced by repeated phencyclidine (PCP) treatment. After a baseline test with saline, male …

Anxiolytic-Like Property Of Risperidone And Olanzapine As Examined In Multiple Measures Of Fear In Rats, Tao Sun, Wei He, Gang Hu, Ming Li

Department of Psychology: Faculty Publications

Atypical antipsychotics are also used in the treatment of anxiety-related disorders. Clinical and preclinical evidence regarding their intrinsic anxiolytic efficacy has been mixed. In this study, we examined the potential anxiolytic-like effects of risperidone and olanzapine, and compared them with haloperidol, chlordiazepoxide (a prototype of sedative–anxiolytic drug) or citalopram (a selective serotonin reuptake inhibitor). We used a composite of two-way avoidance conditioning and acoustic startle reflex model and examined the effects of drug treatments during the acquisition phase (Experiment 1) or extinction phase (Experiments 2 and 3) on multiple measures of conditioned and unconditioned fear/anxiety-like responses. In Experiment 4, we …

Distinct Neural Mechanisms Underlying Acute And Repeated Administration Of Antipsychotic Drugs In Rat Avoidance Conditioning, Ming Li, Tao Sun, Chen Zhang, Gang Hu

Department of Psychology: Faculty Publications

Rationale — Acute antipsychotic treatment disrupts conditioned avoidance responding, and repeated treatment induces a sensitization- or tolerance-like effect. However, the neurochemical mechanisms underlying both acute and repeated antipsychotic effects remain to be determined.

Objective — The present study examined the neuroreceptor mechanisms of haloperidol, clozapine, and olanzapine effect in a rat two-way conditioned avoidance model.

Methods — Well-trained Sprague–Dawley rats were administered with haloperidol (0.05 mg/kg, sc), clozapine (10.0 mg/ kg, sc), or olanzapine (1.0 mg/kg, sc) together with either saline, quinpirole (a selective dopamine D2/3 agonist, 1.0 mg/ kg, sc), or 2,5-dimethoxy-4-iodo-amphetamine (DOI; a selective 5-HT2A/2C agonist, 2.5 mg/kg, …

The Receptor Mechanisms Underlying The Disruptive Effects Of Haloperidol And Clozapine On Rat Maternal Behavior: A Double Dissociation Between Dopamine D2 And 5-Ht2a/2c Receptors, Changjiu Zhao, Ming Li

Department of Psychology: Faculty Publications

Many antipsychotic drugs disrupt active components of maternal behavior such as pup approach, pup retrieval and nest building at clinically relevant doses in postpartum female rats. However, the neurochemical mechanisms underlying such a disruptive effect remain to be determined. This study examined the neurochemical mechanisms that mediate the disruptive effects of haloperidol (a typical antipsychotic) and clozapine (an atypical antipsychotic) on rat maternal behavior. Postpartum rats were administered with haloperidol (0.2 mg/kg, sc) or clozapine (10.0 mg/kg, sc) together with either vehicle (saline or water), quinpirole (a selective dopamine D₂/D₃ agonist, 0.5 or 1.0 mg/kg, sc), or …