Drugs online research references
Dev Psychobiol. 1978 Sep;11(5):405-12.
Exploration in immature rats: effects of drugs.
File SE.
The effects of d-amphetamine (4 mg/kg), scopolamine (1 mg/kg), methylscopolamine (1 mg/kg), and parachlorophenylalanine (400 mg/kg) on exploration were studied in male rats at 16, 21, and 28 days of age. Amphetamine elicited stereotypy at all ages tested, reduced exploration (measured by the time spent head-dipping during a 10-min trial in a holeboard) from Day 21, but did not significantly increase rearing at the ages tested. (Reduced head-dipping, accompanied by stereotypy, is the pattern of results previously seen in adult rats with this dose of amphetamine.) An interesting difference emerged with scopolamine, which reduced head-dipping at all the ages tested, whereas in adults it produced an increase. The age-related difference in drug effects suggests that muscarinic pathways are functioning from Day 16, but that the system concerned with exploration functions differently in mature and immature rats. Both scopolamine and methylscopolamine reduced rearing which suggests that the change is due to peripheral actions of the drugs. Parachlorophenylalanine, which decreases serotonin levels, increased head-dipping, as it has been found to do in adult rats.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=150988&dopt=Abstract
Physiol Behav. 1992 Feb;51(2):381-90.
Perceptual bisection in rats: the effects of physostigmine, scopolamine and pirenzepine.
Shurtleff D, Raslear TG, Genovese RF, Simmons L.
Thermal Stress Adaptation Program, Naval Medical Research Institute, Bethesda, MD 20889-5055.
The effects of cholinergic drugs on three different perceptual bisection tasks were studied in rats. Physostigmine (0.056-0.56 mg/kg), a reversible anticholinesterase, produced dose-dependent decrements in discriminability (A'), but did not affect the bisection point (BP) in visual duration, auditory duration, and auditory intensity bisection tasks. This finding is consistent with results previously obtained in an auditory duration bisection task with an irreversible anticholinesterase, diisopropyl phosphofluoridate. Scopolamine (0.075-0.422 mg/kg), a muscarinic cholinergic-receptor antagonist, produced dose-dependent decrements in both A' and BP in visual and auditory duration bisection tasks. The behavioral antagonism between physostigmine (0.56 mg/kg) and scopolamine (0.075-0.237 mg/kg) was studied in the visual and auditory duration bisection tasks. The BP was not affected by physostigmine alone or in combination with scopolamine, except at the largest dose of scopolamine, which produced a reliable decrement in the BP. A', however, was equally decreased by physostigmine alone and all combinations of physostigmine and scopolamine. Pirenzepine (1, 3 and 10 mg/kg), a selective high-affinity M1 muscarinic antagonist, had no effect on A' or the BP in the duration bisection tasks, suggesting changes in perception produced by muscarinic antagonists do not involve the M1 receptor subtype. The similar drug effects in different sensory modalities (visual and auditory) and perceptual systems (subjective duration and loudness) suggest that cholinergic drugs may affect perceptual mechanisms responsible for sensory coding, such as the output of a neural generator.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1557449&dopt=Abstract
Eur J Pharmacol. 1988 Nov 8;156(3):351-9.
Physostigmine induces in rats a phenomenon resembling long-term potentiation.
Ito T, Miura Y, Kadokawa T.
Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Osaka, Japan.
The study dealt with a phenomenon similar to long-term potentiation of hippocampal population spikes that was observed with a high dose of physostigmine given to rats. The population spikes in the dentate granule cells in anesthetized rats were enhanced to 135, 152 and 167% of the control level 60, 120 and 240 min after the administration of physostigmine (0.1 mg/kg i.v.), respectively. The time course of the enhancement was consistent with that of blocked paired pulse inhibition by physostigmine in anesthetized rats. Such a block of paired pulse inhibition was seen at the observation of the long-term potentiation phenomenon to tetanic stimulation (100 Hz, 2 s). Perfusion of physostigmine (10(-5) M) or bicuculline (10(-6) M) elicited second spikes following the population spikes in CA1 pyramidal cells. The second spikes elicited by physostigmine were decreased by scopolamine (10(-6) M) and muscimol (5 x 10(-7) M), while those caused by bicuculline were decreased by muscimol but not by scopolamine. It is suggested that physostigmine induces a long-term potentiation-like phenomenon through a transient, abrupt increase in excitability and the subsequent block of recurrent GABAergic inhibition in the hippocampus.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3215282&dopt=Abstract
Herbs and Pharmaceuticals Online ||
Hair Million herbal formula for hair loss and hair growth ||
Wellstreet online pharmacy for click-order prescription medications ||
Altace Online Pharmacy ||
Rx Drugs USA, Prescription Drugs Online Pharmacy ||
Insurance plans and information ||
Insurance policies for all purposes ||
Antibiotics and prescription medications online literature ||