Single unit recording in the midbrain of rats during shock-elicited fighting behavior

Single unit activity was recorded extracellularly from the midbrain of rats during fighting behavior and during non-fighting control manipulations. Fighting behavior was elicited by footshock or startle stimuli or occurred spontaneously as a result of prior footshock presentations.

Seven cells were found in the midbrain reticular formation and central gray which displayed maximum firing rates during fighting behavior. These cells also fired to a limited extent to some of the control manipulations, particularly contralateral vibrissae stimulation. These cells fired phasically during fighting behavior and their firing was correlated with either the approach or paw-strike of the opponent animal or to the response of the recording animal to a tactic of the opponent animal. However, no specific movement or sensory event reliably predicted the firing of these cells during fight sequences.

Cells located in other midbrain areas, such as the deep tectum or the area of the red nucleus, also responded during fighting behavior. However, the discharge of these cells was correlated with specific body movements or sensory events. The activity during fighting was similar in rate and pattern to activity during control manipulations whenever similar movements or sensory stimulation were produced. Cells were also found which did not discharge during fighting behavior although they fired under a variety of other conditions.     

Comparison of outcomes of phase II studies and subsequent randomized control studies using identical chemotherapeutic regimens.

PURPOSE: To determine whether promising results from phase II studies could be reproduced in phase III studies, and to examine which characteristics of phase II studies might be of predictive value for subsequent phase III studies. METHODS: We searched for all phase III studies of chemotherapy in advanced solid malignancies, published in the English language literature from July 1998 to June 2003. Each phase III study was reviewed to identify preceding phase II studies. Phase II and phase III studies included in this analysis must have used identical regimens. Data were extracted from both phase II and phase III studies. RESULTS: Of 181 phase III studies identified, 43 used therapeutic regimens identical to those in 49 preceding phase II studies. Twelve phase III studies (28%) were "positive." The vast majority (81%) of phase III studies have lower response rates than preceding phase II studies, with a mean difference of 12.9% among all studies analyzed. None of the phase II study characteristics evaluated significantly predicted for "positive" phase III studies, but the sample size of phase II studies demonstrated a trend toward being predictive (P = .083). CONCLUSION: Promising results from phase II studies frequently do not translate into "positive" phase III studies. Response rates in most phase III studies are lower than those in preceding phase II studies.     

The antinociceptive and anxiolytic-like effects of the metabotropic glutamate receptor 5 (mGluR5) antagonists, MPEP and MTEP, and the mGluR1 antagonist, LY456236, in rodents: a comparison of efficacy and side-effect profiles

Rationale Modulation of metabotropic glutamate receptor (mGluR) subtypes represents a novel approach for the treatment of neurological and psychiatric disorders.Objectives This study was conducted to investigate the role of the mGluR5 and mGluR1 subtypes in the modulation of pain and anxiety.Methods The mGluR5 antagonists, 2-methyl-6-(phenylethynyl)pyridine (MPEP) and 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP), and the mGluR1 antagonist, (4-methoxy-phenyl)-(6-methoxy-quinazolin-4-yl)-amine HCl (LY456236), were tested in models of pain [mouse formalin test, rat spinal nerve ligation (SNL)] and anxiety [Vogel conflict, conditioned lick suppression (CLS)], and their efficacious effects were compared to any associated side effects.Results The systemic administration of MPEP, MTEP, and LY456236 reduced hyperalgesia induced by formalin and mechanical allodynia following SNL. However, only LY456236 completely reversed the allodynia. In the anxiety models, MPEP (3–30 mg/kg), MTEP (3–10 mg/kg), and LY456236 (10–30 mg/kg) produced anxiolytic-like effects similar to the benzodiazepine, chlordiazepoxide (CDP, 6 mg/kg). However, only MPEP and MTEP were able to produce a level of anxiolysis comparable to CDP. In a series of tests examining potential side effects, MPEP and MTEP reduced body temperature and locomotor activity and impaired operant responding for food and rotarod performance at doses of 3–30 and 1–30 mg/kg, respectively. LY456236 reduced operant responding at 30 mg/kg.Conclusion Both mGluR5 and mGluR1 antagonists are effective in models of pain and anxiety. However, an mGluR1 antagonist was more efficacious than the two mGluR5 antagonists in the pain models, which, conversely, appeared more efficacious in the anxiety models. These findings support the potential utility of mGluR5 and mGluR1 antagonists for both the treatment of chronic pain and as novel anxiolytics.     

Quality of life in schizophrenia: a multicenter, randomized, naturalistic, controlled trial comparing olanzapine to first-generation antipsychotics

OBJECTIVE: To assess the effectiveness of olanzapine for treating schizophrenia and to assess if olanzapine promotes a better quality of life than first-generation antipsychotics (FGAs). METHOD: Multicenter, naturalistic, randomized controlled study, comparing olanzapine with FGAs, at hospitalization and during a 9-month follow-up. Outcome assessors were blind to the allocated drug. The dose of antipsychotic was determined by doctors according to their clinical practice routines. Data collection was performed from April 1999 to August 2001. RESULTS: 197 patients with DSM-IV-diagnosed schizophrenia were allocated to olanzapine (N = 104) and FGA (N = 93). Patients taking olanzapine showed greater improvements in Positive and Negative Syndrome Scale (PANSS) negative symptoms (mean difference = 2.3, 95% CI = 0.6 to 4.1) and general psychopathology (mean difference = 4.0, 95% CI = 0.8 to 7.2) sub-scales and fewer incidences of tardive dyskinesia (RR = 2.4, 95% CI = 1.4 to 4.2, p < .0001). Olanzapine was also associated with greater improvement in a number of health-related quality-of-life outcomes on the Medical Outcomes Study 36-item Short-Form Health Survey, including physical functioning (mean difference = 6.6, 95% CI = 1.2 to 11.9), physical role limitations (mean difference = 13.7, 95% CI = 3.0 to 24.3), and emotional role limitations (mean difference = 12.1, 95% CI = 0.7 to 23.5). Patients taking olanzapine gained significantly more weight during the trial than patients taking FGAs, with a correspondent endpoint increase in the body mass index (BMI) of 28.7 versus 25.3 (p < .001). CONCLUSION: Compared with FGAs, olanzapine has advantages in terms of improvements of negative symptoms and quality of life. It is also associated with fewer incidences of tardive dyskinesia and greater increases in weight and BMI. These findings are highlighted by the naturalistic approach adopted in this trial.