Medicine and Health Sciences Commons^™

Effects Of Repeated Quetiapine Treatment On Conditioned Avoidance Responding In Rats, Jun Gao, Min Feng, Natashia Swalve, Collin Davis, Nan Sui, Ming Li

Department of Psychology: Faculty Publications

The present study characterized the behavioral mechanisms of avoidance–disruptive effect of quetiapine in the conditioned avoidance response test under two behavioral testing (2 warning signals vs. 1 warning signal) and two drug administration conditions (subcutaneous vs. intravenous). In Experiments 1 and 2, well-trained adult male Sprague-Dawley rats were tested under the subcutaneous (s.c.) quetiapine treatment (5.0, 15.0, 25.0, 50.0 mg/kg) for 7 days in a novel procedure consisting of two conditioned stimuli (CS) (white noise serving as CS1 and pure tone as CS2). Only the highest dose (50.0 mg/kg) produced a persistent suppression of the avoidance response without impairing the …

Adult Response To Olanzapine Or Clozapine Treatment Is Altered By Adolescent Antipsychotic Exposure: A Preclinical Test In The Phencyclidine Hyperlocomotion Model, Qing Shu, Gang Hu, Ming Li

Department of Psychology: Faculty Publications

This study examined how repeated olanzapine (OLZ) or clozapine (CLZ) treatment in adolescence alters sensitivity to the same drug in adulthood in the phencyclidine (PCP) hyperlocomotion model. Male adolescent Sprague-Dawley rats (postnatal day (P) 44–48) were first treated with OLZ (1.0 or 2.0 mg/kg, subcutaneously (sc)) or CLZ (10.0 or 20.0 mg/kg, sc) and tested in the PCP (3.2 mg/kg, sc)-induced hyperlocomotion model for five consecutive days. Then a challenge test with OLZ (0.5 mg/kg) or CLZ (5.0 mg/kg) was administered either during adolescence (~P 51) or after the rats matured into adults (~P 76 and 91). During adolescence, repeated …

Environmental And Behavioral Controls Of The Expression Of Clozapine Tolerance: Evidence From A Novel Across-Model Transfer Paradigm, Min Feng, Nan Sui, Ming Li

Department of Psychology: Faculty Publications

Repeated administration of antipsychotic drugs induces a sensitization-like or tolerance-like effect in many behavioral tasks, including the conditioned avoidance response (CAR) and the phencyclidine (PCP)-induced hyperlocomotion, two rodent models with high predictive validity for antipsychotic activity. This study investigated the impacts of contextual and behavioral variables on the expression of clozapine tolerance using a recently validated across-model transfer paradigm (Zhang and Li, 2012). Male Sprague-Dawley rats were first repeatedly treated with clozapine (2.5–10.0 mg/kg, sc) in the CAR model or PCP (1.6 mg/kg, sc)-induced hyperlocomotion model for five consecutive days. They were then tested for the expression of clozapine tolerance …

Clozapine, But Not Olanzapine, Disrupts Conditioned Avoidance Response In Rats By Antagonizing 5-Ht2a/2c Receptors, Ming Li, Tao Sun, Alexa Mead

Department of Psychology: Faculty Publications

The present study was designed to assess the role of 5-HT_2A/2C receptors in the acute and repeated effect of clozapine and olanzapine in a rat conditioned avoidance response model, a validated model of antipsychotic activity. Male Sprague–Dawley rats that were previously treated with either phencyclidine (0.5–2.0 mg/kg, sc), amphetamine (1.25–5.0 mg/kg, sc), or saline and tested in a prepulse inhibition of acoustic startle study were used. They were first trained to acquire avoidance response to a white noise (CS1) and a pure tone (CS2) that differed in their ability to predict the occurrence of footshock. Those who acquired avoidance …

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, …

Sedation And Disruption Of Maternal Motivation Underlie The Disruptive Effects Of Antipsychotic Treatment On Rat Maternal Behavior, Changjiu Zhao, Ming Li

Department of Psychology: Faculty Publications

The behavioral mechanisms underlying antipsychotic-induced maternal behavior deficits were examined in the present study. Different groups of postpartum rats were treated with haloperidol (0.1 mg/kg), clozapine (10.0 mg/kg), chlordiazepoxide (5.0 mg/kg, an anxiolytic) or vehicle (0.9% saline) on Days 4 and 6 postpartum and their maternal behaviors were tested under either pup-separation (e.g. pups were removed from their mothers for 4 h before testing) or no-pup-separation condition. Maternal behavior and drug-induced sedation were further tested for 3 days from Day 8 to 12 postpartum. Results show that pup-separation, which putatively increases maternal motivation, did significantly shorten clozapine-elongated pup approach latency, …