Anxiolytic effects of mecamylamine in two animal models of anxiety.

Clinical and preclinical evidence suggests that mecamylamine, a nicotinic receptor antagonist, may have anxiolytic properties. The purpose of this study was to further investigate the anxiolytic properties of mecamylamine in rats as measured by the Elevated Plus Maze and the Social Interaction models of anxiety and to determine if manipulation of the testing environment (either brightly lit or dimly lit conditions) influenced the results. Results indicate that mecamylamine had significant anxiolytic effects in both the Elevated Plus Maze and Social Interaction Tests and that these effects were dependent on dose administered and the level of anxiety produced under different testing conditions. If confirmed by further clinical research, nicotinic receptor antagonists like mecamylamine may represent a novel class of anxiolytics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The catalepsy test: Its ups and downs.

The typical catalepsy (CPSY) test consists of placing an animal in an unusual posture and recording the time taken to correct this posture. This time is regarded as an index of the intensity of CPSY. CPSY is a robust behavior, and the lack of standardization does not usually hinder its actual detection. However, the intensity of the cataleptic effect is influenced by minor methodological differences, and interpretation and comparison of results across laboratories are difficult. The behavioral CPSY test can use any of several different apparatus, including wire grids, parallel bars, platforms, or pegs, to situate the animals in unusual positions. The most common is the bar test (BT), and despite its wide use in psychopharmacological research, even parameters of this test are not standardized. The present article reviews parameters chosen by investigators that measure CPSY. The methodological issues of repeated testing, scaling of scores, apparatus, animal weight, maximal test duration, behavioral criteria, and other influences are discussed. A brief review of the neuropharmacological basis of CPSY is included. It is argued that a universal, standardized BT be adopted by researchers. New data on a novel automated BT in the Digiscan Activity Monitoring System is presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Asymmetrical effects of unilateral cortical suction lesions: Behavioral characterization.

Assessed behavioral effects of unilateral frontocortical suction lesions in the right and left hemispheres in 24 male Sprague-Dawley rats, using a computerized activity monitoring system. Lesions of the right frontal cortex produced postoperative hyperactivity consisting of increases in the total distance traveled, average distance per movement, and average speed of movement. Vertical, rotational, and stereotypic measures were not changed. Ss receiving left hemisphere lesions did not differ from sham-operated controls on any behavioral variable. The lateralized hyperactivity resulting from lesions of the right frontal cortex was confined to increased length and speed of horizontal movement and did not appear to represent a generalized increase in all components of spontaneous activity. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microcarrier enhanced survival of human and rat fetal ventral mesencephalon cells implanted in the rat striatum

The transplantation of tissue containing dopamine-producing cells into the mammalian central nervous system is an emerging treatment for Parkinson's disease, despite relatively poor survival of implanted tissue. Recent evidence has suggested that Cytodex microcarriers enhance the survival of dopaminergic rat chromaffin cells transplanted into the rat striatum in the absence of immunosuppression. The current study was undertaken to evaluate the survival of rat and human fetal ventral mesencephalic neurons (VM) implanted alone or after attachment to microcarriers in the striatum of rats without immunosuppression. Rat fetal VM neurons demonstrated enhanced survival in the rat striatum when transplanted on microcarriers, compared to their transplantation alone during the 3-mo period examined in the present study. Transplants of human fetal VM neurons on microcarriers also survived remarkably well in the rat striatum without systemic immunosuppression. In contrast, human fetal VM cells transplanted alone into the rat striatum did not survive without systemic immunosuppression. There was no evidence of TH fiber sprouting in the vicinity of any transplant site. These data indicated that Cytodex microcarriers provide enhanced survival of both rat allograft and human xenograft fetal mesencephalic cells in the rat striatum without the necessity of systemic immunosuppression, perhaps by inducing a unique neuron-glia environment.     

The topography of amphetamine and scopolamine-induced hyperactivity: Toward an activity print.

The increased locomotor activity induced by systemic injections of d-amphetamine or scopolamine in rats was studied in Digiscan Animal Activity Monitors. This multifactorial analysis of locomotion demonstrated that activity measures of horizontal (ambulatory), vertical (rearing), stereotypic, and rotational behaviors differed depending on dose and drug. The topographies of these activity variables may be unique for the dopaminergic and cholinergic systems underlying hyperactivity. These results are a first step toward a needed increase in the sophistication of behavioral pharmacological techniques, allowing for the development of specific activity prints for different classes of psychoactive agents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dopaminergic and cholinergic influences on motor behavior in chickens.

Examined the effects and interactions of apomorphine (AP; 0–4.0 mg/kg, ip), haloperidol (HAL; 0–2.0 mg/kg, ip), scopolamine (SCO; 0–2.0 mg/kg, ip), and pilocarpine (PIL; 0–50 mg/kg, ip) on stabilimeter activity and tonic immobility in White Leghorn?×?Black Australorp male chickens. The dopamine receptor agonist AP enhanced motor activity and decreased the duration of tonic immobility behavior in a dose-dependent manner. HAL, a dopamine receptor antagonist, increased the duration of tonic immobility and attenuated AP-induced increase in activity. Motor activity could also be increased by the cholinergic antagonist SCO. In addition SCO decreased the duration of tonic immobility. On the other hand, the cholinergic agonist PIL increased tonic immobility behavior and decreased SCO's effect on motor activity. Studies of the interaction of dopaminergic and cholinergic systems showed that HAL could attenuate the activity-stimulating effects of SCO, whereas PIL had a similar, but lesser, effect on AP-induced activity. Results support the suggestion that in birds, as in mammals, the dopaminergic and cholinergic systems are intimately involved in the expression of motor behavior. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cholinergic lesion of the striatum impairs acquisition and retention of a passive avoidance response.

Significant impairments in the acquisition and retention of a step-down passive avoidance task were found in Sprague-Dawley rats with striatal lesions induced by the cholinergic neurotoxin AF64A. No significant differences between control and AF64A-injected Ss were found in sensitivity to electric shock or in various measures of spontaneous locomotor activity. Striatal choline acetyltransferase (CAT) activity was significantly decreased in AF64A-treated Ss compared to controls, whereas glutamic acid decarboxylase (GAD) activities were not. Furthermore, there were no significant differences between groups in CAT and GAD in either the cortex or the hippocampus, supporting the specificity of the lesion to the striatum. The passive avoidance deficits support a role for the striatal cholinergic system in complex behavioral processes. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automated measurement of rearing behavior in adult and neonatal rats.

Three variables constituting an index of rearing behavior from an animal-activity monitoring system were compared with a standard visual rating in 10–30 day old and adult Sprague-Dawley rats. All 3 automated measures correlated significantly with measures rated by visual observation, although only the "number of vertical episodes" was similar in magnitude to the actual number of observed rearings. The height of the vertical sensors was critical in detecting rearings, although reliable results were obtained over a relatively wide range of heights. Analyses in neonates demonstrated developmental progression in rearing behavior, with an onset around Day 15 of age. This automated technique eliminated confounding variables, such as experimenter bias, commonly associated with visual observation techniques. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dietary Supplementations as Neuroprotective Therapies: Focus on NT-020 Diet Benefits in a Rat Model of Stroke

Stroke remains the number one cause of disability in the adult population. Despite scientific progress in our understanding of stroke pathology, only one treatment (tissue plasminogen activator or tPA) is able to afford benefits but to less than 3% of ischemic stroke patients. The development of experimental dietary supplement therapeutics designed to stimulate endogenous mechanisms that confer neuroprotection is likely to open new avenues for exploring stroke therapies. The present review article evaluates the recent literature supporting the benefits of dietary supplementation for the therapy of ischemic stroke. This article focuses on discussing the medical benefits of NT-020 as an adjunct agent for stroke therapy. Based on our preliminary data, a pre-stroke treatment with dietary supplementation promotes neuroprotection by decreasing inflammation and enhancing neurogenesis. However, we recognize that a pre-stroke treatment holds weak clinical relevance. Thus, the main goal of this article is to provide information about recent data that support the assumption of natural compounds as neuroprotective and to evaluate the therapeutic effects of a dietary supplement called NT-020 as in a stroke model. We focus on a systematic assessment of practical treatment parameters so that NT-020 and other dietary supplementations can be developed as an adjunct agent for the prevention or treatment of chronic diseases. We offer rationale for determining the optimal dosage, therapeutic window, and mechanism of action of NT-020 as a dietary supplement to produce neuroprotection when administered immediately after stroke onset. We highlight our long-standing principle in championing both translational and basic science approaches in an effort to fully reveal the therapeutic potential of NT-020 as dietary supplementation in the treatment of stroke. We envision dietary supplementation as an adjunct therapy for stroke at acute, subacute, and even chronic periods.